Purpose
The LUX-Lung 3 study investigated the efficacy of chemotherapy compared with afatinib, a selective, orally bioavailable ErbB family blocker that irreversibly blocks signaling from epidermal growth factor receptor (EGFR/ErbB1), human epidermal growth factor receptor 2 (HER2/ErbB2), and ErbB4 and has wide-spectrum preclinical activity against EGFR mutations. A phase II study of afatinib in EGFR mutation-positive lung adenocarcinoma demonstrated high response rates and progression-free survival (PFS).

Patients and Methods
In this phase III study, eligible patients with stage IIIB/IV lung adenocarcinoma were screened for EGFR mutations. Mutation-positive patients were stratified by mutation type (exon 19 deletion, L858R, or other) and race (Asian or non-Asian) before two-to-one random assignment to 40 mg afatinib per day or up to six cycles of cisplatin plus pemetrexed chemotherapy at standard doses every 21 days. The primary end point was PFS by independent review. Secondary end points included tumor response, overall survival, adverse events, and patient-reported outcomes (PROs).

Results
A total of 1,269 patients were screened, and 345 were randomly assigned to treatment. Median PFS was 11.1 months for afatinib and 6.9 months for chemotherapy (hazard ratio [HR], 0.58; 95% CI, 0.43 to 0.78; P = .001). Median PFS among those with exon 19 deletions and L858R EGFR mutations (n = 308) was 13.6 months for afatinib and 6.9 months for chemotherapy (HR, 0.47; 95% CI, 0.34 to 0.65; P = .001). The most common treatmentrelated adverse events were diarrhea, rash/acne, and stomatitis for afatinib and nausea, fatigue, and decreased appetite for chemotherapy. PROs favored afatinib, with better control of cough, dyspnea, and pain.

Conclusion
Afatinib is associated with prolongation of PFS when compared with standard doublet chemotherapy in patients with advanced lung adenocarcinoma and EGFR mutations.

Phase III study of afatinib or cisplatin plus pemetrexed in patients with metastatic lung adenocarcinoma with EGFR mutations

Immunotherapy is currently the most rapidly advancing area of clinical oncology, and provides the unprecedented opportunity to effectively treat, and even cure, several previously untreatable malignancies. A growing awareness exists of the fact that the success of chemotherapy and radiotherapy, in which the patient's disease can be stabilized well beyond discontinuation of treatment (and occasionally is cured), also relies on the induction of a durable anticancer immune response. Indeed, the local immune infiltrate undergoes dynamic changes that accompany a shift from a pre-existing immune response to a therapy-induced immune response. As a result, the immune contexture, which is determined by the density, composition, functional state and organization of the leukocyte infiltrate of the tumour, can yield information that is relevant to prognosis, prediction of a treatment response and various other pharmacodynamic parameters. Several complementary technologies can be used to explore the immune contexture of tumours, and to derive biomarkers that could enable the adaptation of individual treatment approaches for each patient, as well as monitoring a response to anticancer therapies.

The immune contexture in cancer prognosis and treatment

The induction of CD11b(+)Gr-1(+) myeloid-derived suppressor cells (MDSCs) is an important immune-evading mechanism used by tumors. However, the exact nature and function of MDSCs remain elusive, especially because they constitute a heterogeneous population that has not yet been clearly defined. Here, we identified 2 distinct MDSC subfractions with clear morphologic, molecular, and functional differences. These fractions consisted of either mononuclear cells (MO-MDSCs), resembling inflammatory monocytes, or low-density polymorphonuclear cells (PMN-MDSCs), akin to immature neutrophils. Interestingly, both MO-MDSCs and PMN-MDSCs suppressed antigen-specific T-cell responses, albeit using distinct effector molecules and signaling pathways. Blocking IFN-gamma or disrupting STAT1 partially impaired suppression by MO-MDSCs, for which nitric oxide (NO) was one of the mediators. In contrast, while IFN-gamma was strictly required for the suppressor function of PMN-MDSCs, this did not rely on STAT1 signaling or NO production. Finally, MO-MDSCs were shown to be potential precursors of highly antiproliferative NO-producing mature macrophages. However, distinct tumors differentially regulated this inherent MO-MDSC differentiation program, indicating that this phenomenon was tumor driven. Overall, our data refine tumor-induced MDSC functions by uncovering mechanistically distinct MDSC subpopulations, potentially relevant for MDSC-targeted therapies.

Identification of discrete tumor-induced myeloid-derived suppressor cell subpopulations with distinct T-CELL suppressive activity

For over three decades, a mainstay and goal of clinical oncology has been the development of therapies promoting the effective elimination of cancer cells by apoptosis. This programmed cell death process is mediated by several signalling pathways (referred to as intrinsic and extrinsic) triggered by multiple factors, including cellular stress, DNA damage and immune surveillance. The interaction of apoptosis pathways with other signalling mechanisms can also affect cell death. The clinical translation of effective pro-apoptotic agents involves drug discovery studies (addressing the bioavailability, stability, tumour penetration, toxicity profile in non-malignant tissues, drug interactions and off-target effects) as well as an understanding of tumour biology (including heterogeneity and evolution of resistant clones). While tumour cell death can result in response to therapy, the selection, growth and dissemination of resistant cells can ultimately be fatal. In this Review, we present the main apoptosis pathways and other signalling pathways that interact with them, and discuss actionable molecular targets, therapeutic agents in clinical translation and known mechanisms of resistance to these agents.

Targeting apoptosis in cancer therapy

In recent years, cancer immunotherapy based on immune checkpoint inhibitors (ICIs) has achieved considerable success in the clinic. However, ICIs are significantly limited by the fact that only one third of patients with most types of cancer respond to these agents. The induction of cell death mechanisms other than apoptosis has gradually emerged as a new cancer treatment strategy because most tumors harbor innate resistance to apoptosis. However, to date, the possibility of combining these two modalities has not been discussed systematically. Recently, a few studies revealed crosstalk between distinct cell death mechanisms and antitumor immunity. The induction of pyroptosis, ferroptosis, and necroptosis combined with ICIs showed synergistically enhanced antitumor activity, even in ICI-resistant tumors. Immunotherapy-activated CD8+ T cells are traditionally believed to induce tumor cell death via the following two main pathways: (i) perforin-granzyme and (ii) Fas-FasL. However, recent studies identified a new mechanism by which CD8+ T cells suppress tumor growth by inducing ferroptosis and pyroptosis, which provoked a review of the relationship between tumor cell death mechanisms and immune system activation. Hence, in this review, we summarize knowledge of the reciprocal interaction between antitumor immunity and distinct cell death mechanisms, particularly necroptosis, ferroptosis, and pyroptosis, which are the three potentially novel mechanisms of immunogenic cell death. Because most evidence is derived from studies using animal and cell models, we also reviewed related bioinformatics data available for human tissues in public databases, which partially confirmed the presence of interactions between tumor cell death and the activation of antitumor immunity.

/pdf/ferroptosis-necroptosis-and-pyroptosis-in-anticancer-2p4imy222o.pdf

Ferroptosis, necroptosis, and pyroptosis in anticancer immunity

Radiotherapy (RT) is used routinely as a standard treatment for more than 50% of patients with malignant tumors. The abscopal effect induced by local RT, which is considered as a systemic anti-tumor immune response, reflects the regression of non-irradiated metastatic lesions at a distance from the primary site of irradiation. Since the application of immunotherapy, especially with immune checkpoint inhibitors, can enhance the systemic anti-tumor response of RT, the combination of RT and immunotherapy has drawn extensive attention by oncologists and cancer researchers. Nevertheless, the exact underlying mechanism of the abscopal effect remains unclear. In general, we speculate that the immune mechanism of RT is responsible for, or at least associated with, this effect. In this review, we discuss the anti-tumor effect of RT and immune checkpoint blockade and discuss some published studies on the abscopal effect for this type of combination therapy. In addition, we also evaluate the most appropriate time window for the combination of RT and immune checkpoint blockade, as well as the optimal dose and fractionation of RT in the context of the combined treatment. Finally, the most significant purpose of this review is to identify the potential predictors of the abscopal effect to help identify the most appropriate patients who would most likely benefit from the combination treatment modality.

/pdf/abscopal-effect-of-radiotherapy-combined-with-immune-2gxt0dscmx.pdf

Abscopal effect of radiotherapy combined with immune checkpoint inhibitors

Backgrounds: Radiotherapy (RT) and chemotherapy (CT) can potentiate systemic antitumor immune effect. However, immunomodulation during RT or CT and their clinical implications in rectal cancer have not been thoroughly investigated. Methods: We investigated alterations in the densities of tumor infiltrating lymphocytes (TILs) during chemoradiation and their clinical utilities in patients with rectal cancer. We analyzed 136 rectal cancer patients who underwent neoadjuvant RT, CT or chemoradiotherapy (CRT), followed by radical resection retrospectively. Pretreatment biopsy specimens and posttreatment resected specimens of all patients were immunostained for CD3 and CD8. The predictive value of TILs to neoadjuvant treatment and prognosis were examined. Results: Densities of CD3+ and CD8+TILs in posttreatment specimens after RT, CT or CRT were all significantly higher than those in pretreatment specimens. There were no significant differences between each two of these three groups. High pretreatment CD3+ and CD8+TILs were associated with good response (TRG ≥ 3) after neoadjuvant treatments (P = 0.033 and 0.021). High CD3+TILs and CD8+TILs in pretreatment biopsy specimens were significantly associated with favorable disease free survival (DFS) (P = 0.010 and P = 0.022) and overall survival (OS) (P = 0.019 and P = 0.003). Conclusions: We may, thus, conclude that chemoradiation can enhance local immune response by increased TILs. High TILs densities before treatment are associated with good response to neoadjuvant chemoradiotherapy and a favorable prognosis.

Tumor infiltrating lymphocytes (TILs) before and after neoadjuvant chemoradiotherapy and its clinical utility for rectal cancer.

Tumor-infiltrating lymphocytes, forkhead box P3, programmed death ligand-1, and cytotoxic T lymphocyte-associated antigen-4 expressions before and after neoadjuvant chemoradiation in rectal cancer.

As immunotherapy has gained increasing interest as a new foundation for cancer therapy, some atypical response patterns, such aspseudoprogression and hyperprogression, have garnered the attention of physicians. Pseudoprogression is a phenomenon inwhich an initial increase in tumor size is observed or new lesions appear, followed by a decrease in tumor burden; thisphenomenon can benefit patients receiving immunotherapy but often leads to premature discontinuation of treatment owing tothe false judgment of progression. Accurately recognizing pseudoprogression is also a challenge for physicians. Because of theextensive attention on pseudoprogression, significant progress has been made. Some new criteria for immunotherapy, such asirRC, iRECIST and imRECIST, were proposed to accurately evaluate the response to immunotherapy. Many new detectionindexes, such as ctDNA and IL-8, have also been used to identify pseudoprogression. In this review, the definition, evaluationcriteria, mechanism, monitoring, management and prognosis of pseudoprogression are summarized, and diagnostic andtreatment processes for patients with progression but with a suspicion of pseudoprogression are proposed; these processes couldbe helpful for physicians in clinical practice and enhances the understanding of pseudoprogression. Cite this article as: Jia W, Gao Q, Han A, Zhu H, Yu J. The potentialmechanism, recognition and clinical significance of tumor pseudoprogressionafter immunotherapy. Cancer Biol Med. 2019; 16: 655-70. doi:10.20892/j.issn.2095-3941.2019.0144

http://www.cancerbiomed.org/index.php/cocr/article/download/1502/1494

The potential mechanism, recognition and clinical significance of tumor pseudoprogression after immunotherapy

The role of long noncoding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) and its functional single nucleotide polymorphisms (SNPs) in papillary thyroid carcinoma (PTC) is still largely unclear. Therefore, we investigated the involvement of lncRNA HOTAIR and its three haplotype-tagging SNPs (htSNPs) in PTC. There was higher expression of HOTAIR in PTC tissues compared to normal tissues. A series of gain-loss assays demonstrated that HOTAIR acts as a PTC oncogene via promoting tumorigenic properties of PTC cells. Additionally, the functional HOTAIR rs920778 genetic variant was a PTC susceptibility SNP. Subjects with the HOTAIR rs920778 TT genotype had an odds ratio (OR) of 1.88, 1.25 and 1.61 (P = 6.0 × 10−6, P = 0.028 and P = 3.2 × 10−5) for developing PTC in Shandong, Jiangsu and Jilin case-control sets compared with subjects with the CC genotype. This statistically significant associations were only found between the rs920778 genetic polymorphism and PTC risk in females but not in males. The allele-specific regulation on HOTAIR expression by the rs920778 SNP was confirmed both in vitro and in vivo. Our results demonstrate that functional SNPs influencing lncRNA regulation may explain a part of PTC genetic basis.

/pdf/onco-lncrna-hotair-and-its-functional-genetic-variants-in-3zs2toihb2.pdf

Hui Zhu

Papers

Abscopal effect of radiotherapy combined with immune checkpoint inhibitors

Tumor infiltrating lymphocytes (TILs) before and after neoadjuvant chemoradiotherapy and its clinical utility for rectal cancer.

Tumor-infiltrating lymphocytes, forkhead box P3, programmed death ligand-1, and cytotoxic T lymphocyte-associated antigen-4 expressions before and after neoadjuvant chemoradiation in rectal cancer.

The potential mechanism, recognition and clinical significance of tumor pseudoprogression after immunotherapy

Onco-lncRNA HOTAIR and its functional genetic variants in papillary thyroid carcinoma.