Showing papers in "Clinical Cancer Research in 2012"
TL;DR: The current understanding of the PDA tumor microenvironment is reviewed, opportunities for further exploration that may benefit patients are highlighted, and methods that alter stromal composition or function are under active investigation.
Abstract: Pancreatic ductal adenocarcinoma (PDA) is a common and lethal malignancy resulting in more than 250,000 deaths per year worldwide. Despite extensive efforts, cytotoxic and targeted therapies have provided only limited efficacy for patients with PDA to date. One contributing factor to the failure of systemic therapies may be the abundant tumor stromal content that is the characteristic of PDA. The PDA stroma, aptly termed the tumor microenvironment, occupies the majority of the tumor mass, and consists of a dynamic assortment of extracellular matrix components and nonneoplastic cells including fibroblastic, vascular, and immune cells. Recent work has revealed that the PDA stroma supports tumor growth and promotes metastasis and simultaneously serves as a physical barrier to drug delivery. Accordingly, methods that alter stromal composition or function, for instance interference with the vasculature via Notch/Hedgehog pathway inhibition or relief of vascular compression by hyaluronidase, are under active investigation. Here, we will review our current understanding of the PDA tumor microenvironment, and highlight opportunities for further exploration that may benefit patients.
1,078 citations
TL;DR: Crizotinib resistance in ALK+ NSCLC occurs through somatic kinase domain mutations, ALK gene fusion CNG, and emergence of separate oncogenic drivers.
Abstract: Purpose: Patients with anaplastic lymphoma kinase ( ALK ) gene rearrangements often manifest dramatic responses to crizotinib, a small-molecule ALK inhibitor. Unfortunately, not every patient responds and acquired drug resistance inevitably develops in those who do respond. This study aimed to define molecular mechanisms of resistance to crizotinib in patients with ALK + non–small cell lung cancer (NSCLC). Experimental Design: We analyzed tissue obtained from 14 patients with ALK + NSCLC showing evidence of radiologic progression while on crizotinib to define mechanisms of intrinsic and acquired resistance to crizotinib. Results: Eleven patients had material evaluable for molecular analysis. Four patients (36%) developed secondary mutations in the tyrosine kinase domain of ALK . A novel mutation in the ALK domain, encoding a G1269A amino acid substitution that confers resistance to crizotinib in vitro , was identified in two of these cases. Two patients, one with a resistance mutation, exhibited new onset ALK copy number gain (CNG). One patient showed outgrowth of epidermal growth factor receptor ( EGFR ) mutant NSCLC without evidence of a persistent ALK gene rearrangement. Two patients exhibited a KRAS mutation, one of which occurred without evidence of a persisting ALK gene rearrangement. One patient showed the emergence of an ALK gene fusion–negative tumor compared with the baseline sample but with no identifiable alternate driver. Two patients retained ALK positivity with no identifiable resistance mechanism. Conclusions: Crizotinib resistance in ALK + NSCLC occurs through somatic kinase domain mutations, ALK gene fusion CNG, and emergence of separate oncogenic drivers. Clin Cancer Res; 18(5); 1472–82. ©2012 AACR .
1,029 citations
TL;DR: Success will likely lie in treating cancers that are addicted to particular driver oncogene products that are sensitive Hsp90 clients, as well as malignancies in which buffering of proteotoxic stress is critical for survival.
Abstract: Heat shock protein (Hsp) 90 is an ATP-dependent molecular chaperone exploited by malignant cells to support activated oncoproteins, including many cancer-associated kinases and transcription factors, and is essential for oncogenic transformation. Originally viewed with skepticism, Hsp90 inhibitors are now actively pursued by the pharmaceutical industry, with 17 agents having entered clinical trials. Hsp90’s druggability was established using the natural products geldanamycin and radicicol which mimic the unusual ATP structure adopted in the chaperone’s N-terminal nucleotide-binding pocket and cause potent and selective blockade of ATP binding/hydrolysis, inhibit chaperone function, deplete oncogenic clients, and demonstrate antitumor activity. Preclinical data with these natural products have heightened interest in Hsp90 as a drug target, and 17-allylamino-17-demethoxygeldanamycin (17-AAG, tanespimycin) has demonstrated clinical activity (as defined by RECIST criteria) in HER2+ breast cancer. Many optimized synthetic small molecule Hsp90 inhibitors from diverse chemotypes are now in clinical trials. We review the discovery and development of Hsp90 inhibitors and assess their future potential. There has been significant learning from experience in both the basic biology and the translational drug development around Hsp90, enhanced by the use of Hsp90 inhibitors as chemical probes. Success will likely lie in treating cancers addicted to particular driver oncogene products, such as HER2, ALK, EGFR and BRAF, that are sensitive Hsp90 clients, as well as in malignancies, especially multiple myeloma, where buffering of proteotoxic stress is critical for survival. We discuss approaches to enhancing the effectiveness of Hsp90 inhibitors and highlight new chaperone and stress response pathway targets, including HSF1 and Hsp70.
830 citations
TL;DR: Lifetime risks for a variety of cancers, now extending to colorectal cancer, kidney cancer, and melanoma, are increased in patients with PTEN mutations, and a comprehensive approach is proposed to surveillance of patients withPTEN mutations.
Abstract: Purpose: Age-adjusted cancer incidence and age-related penetrance studies have helped guide cancer risk assessment and management. PTEN hamartoma tumor syndrome (PHTS) is a term encompassing subsets of several clinical syndromes with germline mutations in the PTEN tumor suppressor gene. We conducted the first prospective study to clarify corresponding cancer risks to shed biologic insights on human germline PTEN mutations, and to better inform current surveillance recommendations on the basis of expert opinion. Experimental Design: A series of 3,399 individuals meeting relaxed International Cowden Consortium PHTS criteria were prospectively recruited; 368 individuals were found to have deleterious germline PTEN mutations. Age-adjusted standardized incidence ratio (SIR) calculations and genotype–phenotype analyses were carried out. Results: Elevated SIRs were found for carcinomas of the breast [25.4, 95% confidence interval (CI), 19.8–32.0], thyroid (51.1, 38.1–67.1), endometrium (42.9, 28.1–62.8), colorectum (10.3, 5.6–17.4), kidney (30.6, 17.8–49.4), and melanoma (8.5, 4.1–15.6). Estimated lifetime risks were, respectively, 85.2% (95% CI, 71.4%–99.1%), 35.2% (19.7%–50.7%), 28.2% (17.1%–39.3%), 9.0% (3.8%–14.1%), 33.6% (10.4%–56.9%), and 6% (1.6%-9.4%). Promoter mutations were associated with breast cancer, whereas colorectal cancer was associated with nonsense mutations. Conclusion: Lifetime risks for a variety of cancers, now extending to colorectal cancer, kidney cancer, and melanoma, are increased in patients with PTEN mutations. The genotype–phenotype associations here may provide new insights on PTEN structure and function. We propose a comprehensive approach to surveillance of patients with PTEN mutations. Clin Cancer Res; 18(2); 400–7. ©2012 AACR .
711 citations
TL;DR: The molecular subtypes cut across pathologic classification, and class-defining gene signatures show coordinated expression irrespective of pathologic stage and grade, suggesting the molecular phenotypes as intrinsic properties of the tumors.
Abstract: Purpose Even though urothelial cancer is the fourth most common tumor type among males, progress in treatment has been scarce. A problem in day-to-day clinical practice is that precise assessment of individual tumors is still fairly uncertain; consequently efforts have been undertaken to complement tumor evaluation with molecular biomarkers. An extension of this approach would be to base tumor classification primarily on molecular features. Here, we present a molecular taxonomy for urothelial carcinoma based on integrated genomics. Experimental design We use gene expression profiles from 308 tumor cases to define five major urothelial carcinoma subtypes: urobasal A, genomically unstable, urobasal B, squamous cell carcinoma like, and an infiltrated class of tumors. Tumor subtypes were validated in three independent publically available data sets. The expression of 11 key genes was validated at the protein level by immunohistochemistry. Results The subtypes show distinct clinical outcomes and differ with respect to expression of cell-cycle genes, receptor tyrosine kinases particularly FGFR3, ERBB2, and EGFR, cytokeratins, and cell adhesion genes, as well as with respect to FGFR3, PIK3CA, and TP53 mutation frequency. The molecular subtypes cut across pathologic classification, and class-defining gene signatures show coordinated expression irrespective of pathologic stage and grade, suggesting the molecular phenotypes as intrinsic properties of the tumors. Available data indicate that susceptibility to specific drugs is more likely to be associated with the molecular stratification than with pathologic classification. Conclusions We anticipate that the molecular taxonomy will be useful in future clinical investigations.
689 citations
TL;DR: The interesting duality of c-Myc effects places it in the mainstream of transformational changes and gives it a very important role in regulating the “transformed phenotype.”
Abstract: The processes of cellular growth regulation and cellular metabolism are closely interrelated. The c-Myc oncogene is a "master regulator" which controls many aspects of both of these processes. The metabolic changes which occur in transformed cells, many of which are driven by c-Myc overexpression, are necessary to support the increased need for nucleic acids, proteins, and lipids necessary for rapid cellular proliferation. At the same time, c-Myc overexpression results in coordinated changes in level of expression of gene families which result in increased cellular proliferation. This interesting duality of c-Myc effects places it in the mainstream of transformational changes and gives it a very important role in regulating the "transformed phenotype." The effects induced by c-Myc can occur either as a "primary oncogene" which is activated by amplification or translocation or as a downstream effect of other activated oncogenes. In either case, it appears that c-Myc plays a central role in sustaining the changes which occur with transformation. Although efforts to use c-Myc as a therapeutic target have been quite frustrating, it appears that this may change in the next few years.
634 citations
TL;DR: The increase in tumor-infiltrating lymphocytes induced by treatment with BRAf inhibitors provides strong support for conducting trials that combine BRAF inhibitors with immunotherapy in the hope of prolonging clinical responses.
Abstract: Purpose: To evaluate the effects of treatment with the potent mutant BRAF inhibitors GSK2118436 or vemurafenib (PLX4720) on immune responses to metastatic melanoma in tissues taken before and after treatment. Experimental Design: Thirty-seven tumor biopsies were collected from 15 patients with unresectable American Joint Committee on Cancer stage III or IV melanoma immediately before and approximately 7 days after the commencement of BRAF inhibitor treatment and at the time of tumor progression. Immunohistochemical staining was carried out on the biopsies using specific antibodies for CD8, CD4, CD20, CD1a, and Granzyme B. Results: Tumor infiltration by CD4 + and CD8 + lymphocytes increased markedly following BRAF inhibitor treatment (both ρ = 0.015). There was a correlation between the degree of tumor infiltration by CD8 + and Granzyme B–expressing lymphocytes in post–BRAF inhibitor–treated biopsies ( r = 0.690 and ρ = 0.013). Increased intratumoral CD8 + lymphocyte expression was correlated with a reduction in tumor size and an increase in necrosis in posttreatment biopsies ( r = −0.793, ρ = 0.011; and r = 0.761, ρ = 0.004, respectively). Conclusions: The increase in tumor-infiltrating lymphocytes induced by treatment with BRAF inhibitors provides strong support for conducting trials that combine BRAF inhibitors with immunotherapy in the hope of prolonging clinical responses. Clin Cancer Res; 18(5); 1386–94. ©2011 AACR .
577 citations
TL;DR: AP-1 signaling and EBV infection represent alternative mechanisms of PD-L1 induction and extend the spectrum of tumors in which to consider PD-1 blockade.
Abstract: Purpose: Programmed cell death ligand 1 (PD-L1) is a molecule expressed on antigen-presenting cells that engages the PD-1 receptor on T cells and inhibits T-cell receptor signaling. The PD-1 axis can be exploited by tumor cells to dampen host antitumor immune responses and foster tumor cell survival. PD-1 blockade has shown promise in multiple malignancies but should be directed toward patients in whom it will be most effective. In recent studies, we found that the chromosome 9p24.1 amplification increased the gene dosage of PD-L1 and its induction by JAK2 in a subset of patients with classical Hodgkin lymphoma (cHL). However, cHLs with normal 9p24.1 copy numbers also expressed detectable PD-L1, prompting analyses of additional PD-L1 regulatory mechanisms. Experimental Design: Herein, we utilized immunohistochemical, genomic, and functional analyses to define alternative mechanisms of PD-L1 activation in cHL and additional EBV+ lymphoproliferative disorders. Results: We identified an AP-1–responsive enhancer in the PD-L1 gene. In cHL Reed–Sternberg cells, which exhibit constitutive AP-1 activation, the PD-L1 enhancer binds AP-1 components and increases PD-L1 promoter activity. In addition, we defined Epstein–Barr virus (EBV) infection as an alternative mechanism for PD-L1 induction in cHLs with diploid 9p24.1. PD-L1 was also expressed by EBV-transformed lymphoblastoid cell lines as a result of latent membrane protein 1–mediated, JAK/STAT-dependent promoter and AP-1–associated enhancer activity. In addition, more than 70% of EBV+ posttransplant lymphoproliferative disorders expressed detectable PD-L1. Conclusions: AP-1 signaling and EBV infection represent alternative mechanisms of PD-L1 induction and extend the spectrum of tumors in which to consider PD-1 blockade. Clin Cancer Res; 18(6); 1611–8. ©2012 AACR.
555 citations
TL;DR: Preclinical and early data from clinical studies suggest that targeting this pathway can induce durable clinical responses in patients in a variety of tumor types, including lung and colon cancer.
Abstract: The aim of T-cell-based immune therapy for cancer has been to generate durable clinical benefit for patients. Following a generation of therapies that largely showed minimal activity, substantial toxicity, and no biomarkers to identify which patients benefit from treatment, early studies are showing signs that programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) inhibitors are highly active. Preclinical and early data from clinical studies suggest that targeting this pathway can induce durable clinical responses in patients in a variety of tumor types, including lung and colon cancer. Furthermore, correlations with tumor PD-L1 expression may enable selection of patients most likely to benefit from treatment. The emerging data not only offer the hope of better cancer therapy but also provide evidence that changes our understanding of how the host immune system interacts with human cancer.
540 citations
TL;DR: In this paper, β-adrenergic signaling has been found to regulate multiple cellular processes that contribute to the initiation and progression of cancer, including inflammation, angiogenesis, apoptosis/anoikis, cell motility and trafficking, activation of tumorassociated viruses, DNA damage repair, cellular immune response, and epithelial-mesenchymal transition.
Abstract: β-adrenergic signaling has been found to regulate multiple cellular processes that contribute to the initiation and progression of cancer, including inflammation, angiogenesis, apoptosis/anoikis, cell motility and trafficking, activation of tumor-associated viruses, DNA damage repair, cellular immune response, and epithelial-mesenchymal transition. In several experimental cancer models, activation of the sympathetic nervous system promotes the metastasis of solid epithelial tumors and the dissemination of hematopoietic malignancies via β-adrenoreceptor-mediated activation of PKA and EPAC signaling pathways. Within the tumor microenvironment, β-adrenergic receptors on tumor and stromal cells are activated by catecholamines from local sympathetic nerve fibers (norepinephrine) and circulating blood (epinephrine). Tumor-associated macrophages are emerging as key targets of β-adrenergic regulation in several cancer contexts. Sympathetic nervous system regulation of cancer cell biology and the tumor microenvironment has clarified the molecular basis for long-suspected relationships between stress and cancer progression and now suggest a highly leveraged target for therapeutic intervention. Epidemiologic studies have linked the use of β-blockers to reduced rates of progression for several solid tumors, and pre-clinical pharmacologic and biomarker studies are now laying the groundwork for translation of β-blockade as a novel adjuvant to existing therapeutic strategies in clinical oncology.
499 citations
TL;DR: The angiogenesis biomarkers Ang2 and VEGF were independent predictors of survival in patients with advanced HCC, and none of the biomarkers tested significantly predicted response to sorafenib.
Abstract: The angiogenesis biomarkers Ang2 and VEGF were independent predictors of survival in patients with advanced HCC. In contrast, none of the biomarkers tested significantly predicted response to sorafenib.
TL;DR: The distinct types of KRAS mutations in smokers versus never smokers suggest that most KRAS-mutant lung cancers in never smokers are not due to second-hand smoke exposure, and a heightened susceptibility to tobacco carcinogens.
Abstract: Purpose: The molecular epidemiology of most EGFR and KRAS mutations in lung cancer remains unclear. Experimental Design: We genotyped 3,026 lung adenocarcinomas for the major EGFR (exon 19 deletions and L858R) and KRAS (G12, G13) mutations and examined correlations with demographic, clinical, and smoking history data. Results: EGFR mutations were found in 43% of never smokers and in 11% of smokers. KRAS mutations occurred in 34% of smokers and in 6% of never smokers. In patients with smoking histories up to 10 pack-years, EGFR predominated over KRAS . Among former smokers with lung cancer, multivariate analysis showed that, independent of pack-years, increasing smoking-free years raise the likelihood of EGFR mutation. Never smokers were more likely than smokers to have KRAS G > A transition mutation (mostly G12D; 58% vs. 20%, P = 0.0001). KRAS G12C, the most common G > T transversion mutation in smokers, was more frequent in women ( P = 0.007) and these women were younger than men with the same mutation (median 65 vs. 69, P = 0.0008) and had smoked less. Conclusions: The distinct types of KRAS mutations in smokers versus never smokers suggest that most KRAS -mutant lung cancers in never smokers are not due to second-hand smoke exposure. The higher frequency of KRAS G12C in women, their younger age, and lesser smoking history together support a heightened susceptibility to tobacco carcinogens. Clin Cancer Res; 18(22); 6169–77. ©2012 AACR .
TL;DR: The results suggest that identifying specific molecular abnormalities and choosing therapy based on these abnormalities is relevant in phase I clinical trials, using targeted agents matched with tumor molecular aberrations.
Abstract: Purpose: We initiated a personalized medicine program in the context of early clinical trials, using targeted agents matched with tumor molecular aberrations. Herein, we report our observations. Patient and Methods: Patients with advanced cancer were treated in the Clinical Center for Targeted Therapy. Molecular analysis was conducted in the MD Anderson Clinical Laboratory Improvement Amendments (CLIA)–certified laboratory. Patients whose tumors had an aberration were treated with matched targeted therapy, when available. Treatment assignment was not randomized. The clinical outcomes of patients with molecular aberrations treated with matched targeted therapy were compared with those of consecutive patients who were not treated with matched targeted therapy. Results: Of 1,144 patients analyzed, 460 (40.2%) had 1 or more aberration. In patients with 1 molecular aberration, matched therapy ( n = 175) compared with treatment without matching ( n = 116) was associated with a higher overall response rate (27% vs. 5%; P P P = 0.017). Matched targeted therapy was associated with longer TTF compared with their prior systemic therapy in patients with 1 mutation (5.2 vs. 3.1 months, respectively; P P = 0.001) and TTF ( P = 0.0001). Conclusion: Keeping in mind that the study was not randomized and patients had diverse tumor types and a median of 5 prior therapies, our results suggest that identifying specific molecular abnormalities and choosing therapy based on these abnormalities is relevant in phase I clinical trials. Clin Cancer Res; 18(22); 6373–83. ©2012 AACR .
TL;DR: Preclinical models support that navitoclax may enhance sensitivity of SCLC and other solid tumors to standard cytotoxics and Correlative analyses suggest several putative biomarkers of clinical benefit.
Abstract: Purpose: Bcl-2 is a critical regulator of apoptosis that is overexpressed in the majority of small cell lung cancers (SCLC). Nativoclax (ABT-263) is a potent and selective inhibitor of Bcl-2 and Bcl-x L . The primary objectives of this phase IIa study included safety at the recommended phase II dose and preliminary, exploratory efficacy assessment in patients with recurrent and progressive SCLC after at least one prior therapy. Experimental Design: Thirty-nine patients received navitoclax 325 mg daily, following an initial lead-in of 150 mg daily for 7 days. Study endpoints included safety and toxicity assessment, response rate, progression-free and overall survival (PFS and OS), as well as exploratory pharmacodynamic correlates. Results: The most common toxicity associated with navitoclax was thrombocytopenia, which reached grade III–IV in 41% of patients. Partial response was observed in one (2.6%) patient and stable disease in 9 (23%) patients. Median PFS was 1.5 months and median OS was 3.2 months. A strong association between plasma pro–gastrin-releasing peptide (pro-GRP) level and tumor Bcl-2 copy number ( R = 0.93) was confirmed. Exploratory analyses revealed baseline levels of cytokeratin 19 fragment antigen 21-1, neuron-specific enolase, pro-GRP, and circulating tumor cell number as correlates of clinical benefit. Conclusion: Bcl-2 targeting by navitoclax shows limited single-agent activity against advanced and recurrent SCLC. Correlative analyses suggest several putative biomarkers of clinical benefit. Preclinical models support that navitoclax may enhance sensitivity of SCLC and other solid tumors to standard cytotoxics. Future studies will focus on combination therapies. Clin Cancer Res; 18(11); 3163–9. ©2012 AACR .
TL;DR: This report shows that ipilimumab can induce durable, potentially curative tumor regression in a small percentage of patients with metastatic melanoma and seems to have an increased CR rate, but this needs to be tested in a randomized trial.
Abstract: Purpose: Treatment with ipilimumab can cause objective tumor responses in patients with metastatic melanoma. We have treated 177 evaluable patients in three clinical trials and have long-term follow-up to evaluate the durability of responses. Experimental Design: Patients with metastatic melanoma were treated in three trials from 2002 to 2005. In protocol 1, 56 patients received ipilimumab with gp100 peptides. In protocol 2, 36 patients received ipilimumab with interleukin-2. In protocol 3, 85 patients received ipilimumab with intrapatient dose-escalation and were randomized to receive gp100 peptides. We have analyzed their long-term follow-up and survival data. Results: With median follow-up for protocols 1, 2, and 3 being 92, 84, and 71 months, median survival was 14, 16, and 13 months with 5-year survival rates being 13%, 25%, and 23%, respectively. Patients in protocol 2 had a 17% complete response (CR) rate, compared with 7% in protocol 1 and 6% in protocol 3. These CR rates are higher than previously reported for the same trials because some patients who eventually became complete responders had continual tumor regression months to years after therapy. All but one of the 15 complete responders are ongoing at 54+ to 99+ months. Conclusions: This report provides the longest follow-up of patients with melanoma treated with ipilimumab and shows that ipilimumab can induce durable, potentially curative tumor regression in a small percentage of patients with metastatic melanoma. The combination of ipilimumab and interleukin-2 seems to have an increased CR rate, but this needs to be tested in a randomized trial. Clin Cancer Res; 18(7); 2039–47. ©2012 AACR .
TL;DR: In high-grade serous ovarian tumors, CD20+ TIL have an antigen–experienced but atypical CD27− memory B-cell phenotype, and are uncoupled from serum autoantibodies, express markers of antigen-presenting cells, and colocalize with CD8+ T cells.
Abstract: Purpose: Tumor-infiltrating lymphocytes (TIL), in particular CD8 + T cells and CD20 + B cells, are strongly associated with survival in ovarian cancer and other carcinomas. Although CD8 + TIL can mediate direct cytolytic activity against tumors, the role of CD20 + TIL is poorly understood. Here, we investigate the possible contributions of CD20 + TIL to humoral and cellular tumor immunity. Experimental Design: Tumor and serum specimens were obtained from patients with high-grade serous ovarian cancer. CD8 + and CD20 + TIL were analyzed by immunohistochemistry and flow cytometry. Immunoglobulin molecules were evaluated by DNA sequencing. Serum autoantibody responses to the tumor antigens p53 and NY-ESO-1 were measured by ELISA. Results: The vast majority of CD20 + TIL were antigen experienced, as evidenced by class-switching, somatic hypermutation, and oligoclonality, yet they failed to express the canonical memory marker CD27. CD20 + TIL showed no correlation with serum autoantibodies to p53 or NY-ESO-1. Instead, they colocalized with activated CD8 + TIL and expressed markers of antigen presentation, including MHC class I, MHC class II, CD40, CD80, and CD86. The presence of both CD20 + and CD8 + TIL correlated with increased patient survival compared with CD8 + TIL alone. Conclusions: In high-grade serous ovarian tumors, CD20 + TIL have an antigen–experienced but atypical CD27 − memory B-cell phenotype. They are uncoupled from serum autoantibodies, express markers of antigen-presenting cells, and colocalize with CD8 + T cells. We propose that the association between CD20 + TIL and patient survival may reflect a supportive role in cytolytic immune responses. Clin Cancer Res; 18(12); 3281–92. ©2012 AACR .
TL;DR: Different genotypes exist within BRAF-mutant metastatic melanoma, representing biologically and clinically discrete subtypes, suggesting distinct etiology and behavior.
Abstract: Purpose: Certain clinicopathologic features correlate with BRAF mutation status in melanoma including younger age and primary subtype. This study sought to determine the BRAF mutation status by age-decade and whether BRAF -mutant genotypes correlated with clinicopathologic features and outcome in patients with metastatic melanoma.
Methods: A prospectively assembled cohort of Australian patients were followed from diagnosis of metastatic melanoma (N = 308). Clinicopathologic variables were correlated with BRAF mutational status, genotype, and survival.
Results: Forty-six percent of patients had a BRAF mutation; 73% V600E, 19% V600K, and 8% other genotypes. An inverse relationship existed between BRAF mutation prevalence and age-decade ( P 40% in those ≥70 years. A higher degree of cumulative sun-induced damage correlated with V600K but not V600E melanoma ( P = 0.002). The disease-free interval from diagnosis of primary melanoma to first distant metastasis was shorter for patients with V600K compared with V600E melanoma (17.4 vs. 39.2 months, P = 0.048), with no difference in survival thereafter. In patients BRAF tested at diagnosis of metastatic melanoma, one year survival from diagnosis of metastasis was significantly longer for patients with BRAF -mutant melanoma treated with an inhibitor (83%), than those not treated with an inhibitor (29%, P < 0.001), or patients with BRAF wild-type melanoma (37%, P < 0.001).
Conclusion: Different genotypes exist within BRAF -mutant metastatic melanoma, representing biologically and clinically discrete subtypes, suggesting distinct etiology and behavior. Clin Cancer Res; 18(12); 3242–9. ©2012 AACR .
TL;DR: ROS1 inhibition may be an effective treatment strategy for the subset of patients with NSCLC whose tumors express ROS1 fusion genes, and this patient showed tumor shrinkage upon treatment with crizotinib.
Abstract: Purpose: Oncogenic gene fusions involving the 3′ region of ROS1 kinase have been identified in various human cancers. In this study, we sought to characterize ROS1 fusion genes in non–small cell lung cancer (NSCLC) and establish the fusion proteins as drug targets. Experimental Design: An NSCLC tissue microarray (TMA) panel containing 447 samples was screened for ROS1 rearrangement by FISH. This assay was also used to screen patients with NSCLC. In positive samples, the identity of the fusion partner was determined through inverse PCR and reverse transcriptase PCR. In addition, the clinical efficacy of ROS1 inhibition was assessed by treating a ROS1-positive patient with crizotinib. The HCC78 cell line, which expresses the SLC34A2–ROS1 fusion, was treated with kinase inhibitors that have activity against ROS1. The effects of ROS1 inhibition on proliferation, cell-cycle progression, and cell signaling pathways were analyzed by MTS assay, flow cytometry, and Western blotting. Results: In the TMA panel, 5 of 428 (1.2%) evaluable samples were found to be positive for ROS1 rearrangement. In addition, 1 of 48 patients tested positive for rearrangement, and this patient showed tumor shrinkage upon treatment with crizotinib. The patient and one TMA sample displayed expression of the recently identified SDC4–ROS1 fusion, whereas two TMA samples expressed the CD74–ROS1 fusion and two others expressed the SLC34A2–ROS1 fusion. In HCC78 cells, treatment with ROS1 inhibitors was antiproliferative and downregulated signaling pathways that are critical for growth and survival. Conclusions: ROS1 inhibition may be an effective treatment strategy for the subset of patients with NSCLC whose tumors express ROS1 fusion genes. Clin Cancer Res; 18(17); 4570–9. ©2012 AACR .
TL;DR: The results suggest that dual inhibition of both pathways may potentially exhibit favorable efficacy compared with inhibition of either pathway, at the expense of greater toxicity.
Abstract: Purpose: This study evaluated the clinical relevance of the dual-targeting strategy involving PI3K/AKT/mTOR and RAF/MEK/ERK pathways. Experimental Design: We investigated safety, efficacy, and correlations between tumor genetic alterations and clinical benefit in 236 patients with advanced cancers treated with phase I study drugs targeting phosphoinositide 3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways in our Phase I Clinical Trials Program. Results: Seventy-six (32.2%) patients received a PI3K pathway inhibitor in combination with a MAPK pathway inhibitor (D), whereas 124 (52.5%) and 36 (15.3%), respectively, received an inhibitor of either the PI3K or MAPK pathways (S). The rates of drug-related grade >III adverse events were 18.1% for (S) and 53.9% for (D; P P = 0.06). The most frequent grade >III adverse events were transaminase elevations, skin rash, and mucositis. In our comprehensive tumor genomic analysis, of 9 patients who harbored coactivation of both pathways (colorectal cancer, n = 7; melanoma, n = 2), all 5 patients treated with (D) had tumor regression ranging from 2% to 64%. Conclusions: These results suggest that dual inhibition of both pathways may potentially exhibit favorable efficacy compared with inhibition of either pathway, at the expense of greater toxicity. Furthermore, this parallel pathway targeting strategy may be especially important in patients with coexisting PI3K pathway genetic alterations and KRAS or BRAF mutations and suggests that molecular profiling and matching patients with combinations of these targeted drugs will need to be investigated in depth. Clin Cancer Res; 18(8); 2316–25. ©2012 AACR .
TL;DR: It is concluded that FoxP3+ T cells have heterogeneous properties that can be discerned by the use of additional markers and seem to depend on the tumor site, perhaps reflecting microenvironmental differences.
Abstract: CD8+ tumor-infiltrating lymphocytes (TIL) are associated with survival in a variety of cancers. A second subpopulation of TIL, defined by forkhead box protein P3 (FoxP3) expression, has been reported to inhibit tumor immunity, resulting in decreased patient survival. On the basis of this premise, several groups are attempting to deplete FoxP3+ T cells to enhance tumor immunity. However, recent studies have challenged this paradigm by showing that FoxP3+ T cells exhibit heterogeneous phenotypes and, in some cohorts, are associated with favorable prognosis. These discrepant results could arise from differences in study methodologies or the biologic properties of specific cancer types. Here, we conduct the first systematic review of the prognostic significance of FoxP3+ T cells across nonlymphoid cancers (58 studies from 16 cancers). We assessed antibody specificity, cell-scoring strategy, multivariate modeling, use of single compared with multiple markers, and tumor site. Two factors proved important. First, when FoxP3 was combined with one additional marker, double-positive T cells were generally associated with poor prognosis. Second, tumor site had a major influence. FoxP3+ T cells were associated with poor prognosis in hepatocellular cancer and generally good prognosis in colorectal cancer, whereas other cancer types were inconsistent or understudied. We conclude that FoxP3+ T cells have heterogeneous properties that can be discerned by the use of additional markers. Furthermore, the net biologic effects of FoxP3+ T cells seem to depend on the tumor site, perhaps reflecting microenvironmental differences. Thus, depletion of FoxP3+ T cells might enhance tumor immunity in some patient groups but be detrimental in others.
TL;DR: Evidence of a correlation between decreases in CTC counts and radiographic response by either FDG-PET or RECIST in patients with advanced NSCLC is provided and a potential role for using CTC decreases as an early indication of response to therapy and ctDNA for real-time assessment of mutation status from blood is suggested.
Abstract: Purpose:Elevated levels orincreases in circulating tumor cells (CTC) portend poor prognosis in patients with epithelial cancers. Less is known about CTCs as surrogate endpoints or their use for predictive biomarkerevaluation.ThisstudyinvestigatedtheutilityofCTCenumerationandcharacterizationusingthe CellSearch platform, as well as mutation detection in circulating tumor DNA (ctDNA), in patients with advanced non–small cell lung cancer (NSCLC). Experimental Design: Forty-one patients were enrolled in a single-arm phase II clinical trial of erlotinib and pertuzumab. Peripheral blood was analyzed for CTC enumeration, EGFR expression in CTCs, and detection of oncogenic mutations in CTCs and ctDNA. Changes in CTC levels were correlated with 2[18F]fluoro-2-deoxy-D-glucose–positron emission tomographic (FDG-PET) and computed tomographic (CT) imaging and survival endpoints. Results: CTCs were detected (� 1 CTC) at baseline in 78% of patients. Greater sensitivity for mutation detection was observed in ctDNA than in CTCs and detected mutations were strongly concordant with mutation status in matched tumor. Higher baseline CTC counts were associated with response to treatment by Response Evaluation Criteria in Solid Tumors (RECIST, P ¼ 0.009) and decreased CTC counts upon treatment were associated with FDG-PET and RECIST response (P ¼ 0.014 and P ¼ 0.019) and longer progression-free survival (P ¼ 0.050). Conclusion: These data provide evidence of a correlation between decreases in CTC counts and radiographic response by either FDG-PET or RECIST in patients with advanced NSCLC. These findings require prospective validation but suggest a potential role for using CTC decreases as an early indication of response to therapy and ctDNA for real-time assessment of mutation status from blood. Clin Cancer Res; 18(8); 2391–401. � 2012 AACR.
TL;DR: Her2 mutations identify a distinct subset of lung ADCs and given the high prevalence of lung cancer worldwide and the availability of standard and investigational therapies targeting HER2, routine clinical genotyping of lung ADC should include HER2.
Abstract: Purpose: Activating mutations in the tyrosine kinase domain of HER2 (ERBB2) have been described in a subset of lung adenocarcinomas (ADCs) and are mutually exclusive with EGFR and KRAS mutations. The prevalence, clinicopathologic characteristics, prognostic implications, and molecular heterogeneity of HER2 -mutated lung ADCs are not well established in U.S. patients. Experimental Design: Lung ADC samples ( N = 1,478) were first screened for mutations in EGFR (exons 19 and 21) and KRAS (exon 2), and negative cases were then assessed for HER2 mutations (exons 19–20) using a sizing assay and mass spectrometry. Testing for additional recurrent point mutations in EGFR, KRAS, BRAF, NRAS, PIK3CA, MEK1 , and AKT was conducted by mass spectrometry. ALK rearrangements and HER2 amplification were assessed by FISH. Results: We identified 25 cases with HER2 mutations, representing 6% of EGFR/KRAS/ALK -negative specimens. Small insertions in exon 20 accounted for 96% (24/25) of the cases. Compared with insertions in EGFR exon 20, there was less variability, with 83% (20/24) being a 12 bp insertion causing duplication of amino acids YVMA at codon 775. Morphologically, 92% (23/25) were moderately or poorly differentiated ADC. HER 2 mutation was not associated with concurrent HER2 amplification in 11 cases tested for both. HER2 mutations were more frequent among never-smokers ( P Conclusions: HER2 mutations identify a distinct subset of lung ADCs. Given the high prevalence of lung cancer worldwide and the availability of standard and investigational therapies targeting HER2 , routine clinical genotyping of lung ADC should include HER2 . Clin Cancer Res; 18(18); 4910–8. ©2012 AACR .
TL;DR: A growing body of preclinical data shows that inhibition of FGFR signaling can result in antiproliferative and/or proapoptotic effects, both in vitro and in vivo, thus confirming the validity of the FGF/FGFR axis as a potential therapeutic target.
Abstract: The fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) signaling axis plays an important role in normal organ, vascular, and skeletal development. Deregulation of FGFR signaling through genetic modification or overexpression of the receptors (or their ligands) has been observed in numerous tumor settings, whereas the FGF/FGFR axis also plays a key role in driving tumor angiogenesis. A growing body of preclinical data shows that inhibition of FGFR signaling can result in antiproliferative and/or proapoptotic effects, both in vitro and in vivo, thus confirming the validity of the FGF/FGFR axis as a potential therapeutic target. In the past, development of therapeutic approaches to target this axis has been hampered by our inability to develop FGFR-selective agents. With the advent of a number of new modalities for selectively inhibiting FGF/FGFR signaling, we are now in a unique position to test and validate clinically the many hypotheses that have been generated preclinically.
TL;DR: From the results of translational studies and the first clinical phase I/II trials, it can be concluded that targeting HIF-1 and tumor glucose metabolism at several levels reduces the antioxidant capacity of tumors, affects the tumor microenvironment, and sensitizes various solid tumors to irradiation.
Abstract: Radiotherapy, an important treatment modality in oncology, kills cells through induction of oxidative stress. However, malignant tumors vary in their response to irradiation as a consequence of resistance mechanisms taking place at the molecular level. It is important to understand these mechanisms of radioresistance, as counteracting them may improve the efficacy of radiotherapy. In this review, we describe how the hypoxia-inducible factor 1 (HIF-1) pathway has a profound effect on the response to radiotherapy. The main focus will be on HIF-1-controlled protection of the vasculature postirradiation and on HIF-1 regulation of glycolysis and the pentose phosphate pathway. This aberrant cellular metabolism increases the antioxidant capacity of tumors, thereby countering the oxidative stress caused by irradiation. From the results of translational studies and the first clinical phase I/II trials, it can be concluded that targeting HIF-1 and tumor glucose metabolism at several levels reduces the antioxidant capacity of tumors, affects the tumor microenvironment, and sensitizes various solid tumors to irradiation.
TL;DR: Denosumab treatment of patients with GCTB significantly reduced or eliminated RANK-positive tumor giant cells and reduced the relative content of proliferative, densely cellular tumor stromal cells, replacing them with nonproliferative, differentiated, densely woven new bone.
Abstract: Purpose: Giant cell tumor of bone (GCTB) is a locally aggressive, benign osteolytic tumor in which bone destruction is mediated by RANKL. The RANKL inhibitor denosumab is being investigated for treatment of GCTB. We describe histologic analyses of GCTB tumor samples from a phase 2 study of denosumab in GCTB.
Experimental Design: Adult patients with recurrent or unresectable GCTB received subcutaneous denosumab 120 mg every 4 weeks (with additional doses on days 8 and 15). The primary histologic efficacy endpoint was the proportion of patients who had a ≥ 90% elimination of giant cells from their tumor. Baseline and on-study specimens were also evaluated for overall tumor morphology and expression of RANK and RANKL.
Results: Baseline tumor samples were typically composed of densely cellular proliferative RANKL-positive tumor stromal cells, RANK-positive rounded mononuclear cells, abundant RANK-positive tumor giant cells, and areas of scant de novo osteoid matrix and woven bone. In on-study samples from 20 of 20 patients (100%), a decrease of ≥ 90% in tumor giant cells and a reduction in tumor stromal cells were observed. In these analyses, thirteen patients (65%) had an increased proportion of dense fibro-osseous tissue and/or new woven bone, replacing areas of proliferative RANKL positive stromal cells.
Conclusions: Denosumab treatment of patients with GCTB significantly reduced or eliminated RANK-positive tumor giant cells. Denosumab also reduced the relative content of proliferative, densely cellular tumor stromal cells, replacing them with non-proliferative, differentiated, densely woven new bone. Denosumab continues to be studied as a potential treatment for GCTB.
TL;DR: The results indicate that the immunotherapy with expanded autologous TIL is capable of achieving durable clinical responses in patients with metastatic melanoma and that CD8+ T cells in the infused TIL, particularly differentiated effectors cells and cells expressing BTLA, are associated with tumor regression.
Abstract: Purpose: Adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TIL) is a promising treatment for metastatic melanoma unresponsive to conventional therapies. We report here on the results of an ongoing phase II clinical trial testing the efficacy of ACT using TIL in patients with metastatic melanoma and the association of specific patient clinical characteristics and the phenotypic attributes of the infused TIL with clinical response. Experimental Design: Altogether, 31 transiently lymphodepleted patients were treated with their expanded TIL, followed by two cycles of high-dose interleukin (IL)-2 therapy. The effects of patient clinical features and the phenotypes of the T cells infused on the clinical response were determined. Results: Overall, 15 of 31 (48.4%) patients had an objective clinical response using immune-related response criteria (irRC) with 2 patients (6.5%) having a complete response. Progression-free survival of more than 12 months was observed for 9 of 15 (60%) of the responding patients. Factors significantly associated with the objective tumor regression included a higher number of TIL infused, a higher proportion of CD8 + T cells in the infusion product, a more differentiated effector phenotype of the CD8 + population, and a higher frequency of CD8 + T cells coexpressing the negative costimulation molecule “B- and T-lymphocyte attenuator” (BTLA). No significant difference in the telomere lengths of TIL between responders and nonresponders was identified. Conclusion: These results indicate that the immunotherapy with expanded autologous TIL is capable of achieving durable clinical responses in patients with metastatic melanoma and that CD8 + T cells in the infused TIL, particularly differentiated effectors cells and cells expressing BTLA, are associated with tumor regression. Clin Cancer Res; 18(24); 6758–70. ©2012 AACR .
TL;DR: The findings suggest that EGFR/KRAS mutations do not occur in pure pulmonary SQCC, and occasional detection of these mutations in samples diagnosed as “SQCC” is due to challenges with the diagnosis of AD-SQC and adenocarcinoma, which can be largely resolved by comprehensive pathologic assessment incorporating immunohistochemical biomarkers.
Abstract: Purpose: There is persistent controversy as to whether EGFR and KRAS mutations occur in pulmonary squamous cell carcinoma (SQCC). We hypothesized that the reported variability may reflect difficulties in the pathologic distinction of true SQCC from adenosquamous carcinoma (AD-SQC) and poorly differentiated adenocarcinoma due to incomplete sampling or morphologic overlap. The recent development of a robust immunohistochemical approach for distinguishing squamous versus glandular differentiation provides an opportunity to reassess EGFR / KRAS and other targetable kinase mutation frequencies in a pathologically homogeneous series of SQCC. Experimental Design: Ninety-five resected SQCCs, verified by immunohistochemistry as ΔNp63 + /TTF-1 − , were tested for activating mutations in EGFR , KRAS , BRAF , PIK3CA , NRAS , AKT1 , ERBB2 / HER2 , and MAP2K1 / MEK1. In addition, all tissue samples from rare patients with the diagnosis of EGFR / KRAS -mutant “SQCC” encountered during 5 years of routine clinical genotyping were reassessed pathologically. Results: The screen of 95 biomarker-verified SQCCs revealed no EGFR / KRAS [0%; 95% confidence interval (CI), 0%–3.8%], four PIK3CA (4%; 95% CI, 1%–10%), and one AKT1 (1%; 95% CI, 0%–5.7%) mutations. Detailed morphologic and immunohistochemical reevaluation of EGFR / KRAS -mutant “SQCC” identified during clinical genotyping ( n = 16) resulted in reclassification of 10 (63%) cases as AD-SQC and five (31%) cases as poorly differentiated adenocarcinoma morphologically mimicking SQCC (i.e., adenocarcinoma with “squamoid” morphology). One (6%) case had no follow-up. Conclusions: Our findings suggest that EGFR / KRAS mutations do not occur in pure pulmonary SQCC, and occasional detection of these mutations in samples diagnosed as “SQCC” is due to challenges with the diagnosis of AD-SQC and adenocarcinoma, which can be largely resolved by comprehensive pathologic assessment incorporating immunohistochemical biomarkers. Clin Cancer Res; 18(4); 1167–76. ©2012 AACR .
TL;DR: Clinical and preclinical data confirm that IDO expression increases the recruitment of immunosuppressive Tregs that lead to tumor outgrowth, and IDO deficiency decreases Treg recruitment and enhances T-cell–mediated tumor rejection.
Abstract: Purpose: Glioblastoma multiforme (GBM) is an aggressive adult brain tumor with a poor prognosis. One hallmark of GBM is the accumulation of immunosuppressive and tumor-promoting CD4 + FoxP3 + GITR + regulatory T cells (Tregs). Here, we investigated the role of indoleamine 2,3 dioxygenase (IDO) in brain tumors and the impact on Treg recruitment. Experimental Design: To determine the clinical relevance of IDO expression in brain tumors, we first correlated patient survival to the level of IDO expression from resected glioma specimens. We also used novel orthotopic and transgenic models of glioma to study how IDO affects Tregs. The impact of tumor-derived and peripheral IDO expression on Treg recruitment, GITR expression, and long-term survival was determined. Results: Downregulated IDO expression in glioma predicted a significantly better prognosis in patients. Coincidently, both IDO-competent and deficient mice showed a survival advantage bearing IDO-deficient brain tumors, when compared with IDO-competent brain tumors. Moreover, IDO deficiency was associated with a significant decrease in brain-resident Tregs, both in orthotopic and transgenic mouse glioma models. IDO deficiency was also associated with lower GITR expression levels on Tregs. Interestingly, the long-term survival advantage conferred by IDO deficiency was lost in T-cell–deficient mice. Conclusions: These clinical and preclinical data confirm that IDO expression increases the recruitment of immunosuppressive Tregs that lead to tumor outgrowth. In contrast, IDO deficiency decreases Treg recruitment and enhances T-cell–mediated tumor rejection. Thus, the data suggest a critical role for IDO-mediated immunosuppression in glioma and support the continued investigation of IDO–Treg interactions in the context of brain tumors. Clin Cancer Res; 18(22); 6110–21. ©2012 AACR .
TL;DR: These data indicate that ovarian tumors are enriched with CSCs and stem cell pathway mediators, especially at the completion of primary therapy, which suggests that stem cell subpopulations contribute to tumor chemoresistance and ultimately recurrent disease.
Abstract: Purpose: Within heterogeneous tumors, subpopulations often labeled cancer stem cells (CSC) have been identified that have enhanced tumorigenicity and chemoresistance in ex vivo models. However, whether these populations are more capable of surviving chemotherapy in de novo tumors is unknown. Experimental Design: We examined 45 matched primary/recurrent tumor pairs of high-grade ovarian adenocarcinomas for expression of CSC markers ALDH1A1, CD44, and CD133 using immunohistochemistry. Tumors collected immediately after completion of primary therapy were then laser capture microdissected and subjected to a quantitative PCR array examining stem cell biology pathways (Hedgehog, Notch, TGF-β, and Wnt). Select genes of interest were validated as important targets using siRNA-mediated downregulation. Results: Primary samples were composed of low densities of ALDH1A1, CD44, and CD133. Tumors collected immediately after primary therapy were more densely composed of each marker, whereas samples collected at first recurrence, before initiating secondary therapy, were composed of similar percentages of each marker as their primary tumor. In tumors collected from recurrent platinum-resistant patients, only CD133 was significantly increased. Of stem cell pathway members examined, 14% were significantly overexpressed in recurrent compared with matched primary tumors. Knockdown of genes of interest, including endoglin/CD105 and the hedgehog mediators Gli1 and Gli2, led to decreased ovarian cancer cell viability, with Gli2 showing a novel contribution to cisplatin resistance. Conclusions: These data indicate that ovarian tumors are enriched with CSCs and stem cell pathway mediators, especially at the completion of primary therapy. This suggests that stem cell subpopulations contribute to tumor chemoresistance and ultimately recurrent disease. Clin Cancer Res; 18(3); 869–81. ©2011 AACR .
TL;DR: Abnormal histone and DNA methylation are emerging as a common feature of tumors with IDH1 and IDH2 mutations and may cause altered stem cell differentiation and eventual tumorigenesis.
Abstract: Genes encoding for isocitrate dehydrogenases 1 and 2, IDH1 and IDH2, are frequently mutated in multiple types of human cancer. Mutations targeting IDH1 and IDH2 result in simultaneous loss of their normal catalytic activity, the production of α-ketoglutarate (α-KG), and gain of a new function, the production of 2-hydroxyglutarate (2-HG). 2-HG is structurally similar to α-KG, and acts as an α-KG antagonist to competitively inhibit multiple α-KG-dependent dioxygenases, including both lysine histone demethylases and the ten-eleven translocation family of DNA hydroxylases. Abnormal histone and DNA methylation are emerging as a common feature of tumors with IDH1 and IDH2 mutations and may cause altered stem cell differentiation and eventual tumorigenesis. Therapeutically, unique features of IDH1 and IDH2 mutations make them good biomarkers and potential drug targets.