Background We investigated the efficacy of cetuximab plus irinotecan, fluorouracil, and leucovorin (FOLFIRI) as first-line treatment for metastatic colorectal cancer and sought associations between the mutation status of the KRAS gene in tumors and clinical response to cetuximab. Methods We randomly assigned patients with epidermal growth factor receptor–positive colorectal cancer with unresectable metastases to receive FOLFIRI either alone or in combination with cetuximab. The primary end point was progression-free survival. Results A total of 599 patients received cetuximab plus FOLFIRI, and 599 received FOLFIRI alone. The hazard ratio for progression-free survival in the cetuximab–FOLFIRI group as compared with the FOLFIRI group was 0.85 (95% confidence interval [CI], 0.72 to 0.99; P=0.048). There was no significant difference in the overall survival between the two treatment groups (hazard ratio, 0.93; 95% CI, 0.81 to 1.07; P=0.31). There was a significant interaction between treatment group and KRAS ...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa0805019

Cetuximab and chemotherapy as initial treatment for metastatic colorectal cancer.

BACKGROUND Treatment with cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, improves overall and progression-free survival and preserves the quality of life in patients with colorectal cancer that has not responded to chemotherapy. The mutation status of the K-ras gene in the tumor may affect the response to cetuximab and have treatment-independent prognostic value. METHODS We analyzed tumor samples, obtained from 394 of 572 patients (68.9%) with colo rectal cancer who were randomly assigned to receive cetuximab plus best supportive care or best supportive care alone, to look for activating mutations in exon 2 of the K-ras gene. We assessed whether the mutation status of the K-ras gene was associated with survival in the cetuximab and supportive-care groups. RESULTS Of the tumors evaluated for K-ras mutations, 42.3% had at least one mutation in exon 2 of the gene. The effectiveness of cetuximab was significantly associated with K-ras mutation status (P = 0.01 and P<0.001 for the interaction of K-ras mutation status with overall survival and progression-free survival, respectively). In patients with wild-type K-ras tumors, treatment with cetuximab as compared with supportive care alone significantly improved overall survival (median, 9.5 vs. 4.8 months; hazard ratio for death, 0.55; 95% confidence interval [CI], 0.41 to 0.74; P<0.001) and progression-free survival (median, 3.7 months vs. 1.9 months; hazard ratio for progression or death, 0.40; 95% CI, 0.30 to 0.54; P<0.001). Among patients with mutated K-ras tumors, there was no significant difference between those who were treated with cetuximab and those who received supportive care alone with respect to overall survival (hazard ratio, 0.98; P = 0.89) or progression-free survival (hazard ratio, 0.99; P = 0.96). In the group of patients receiving best supportive care alone, the mutation status of the K-ras gene was not significantly associated with overall survival (hazard ratio for death, 1.01; P = 0.97). CONCLUSIONS Patients with a colorectal tumor bearing mutated K-ras did not benefit from cetuximab, whereas patients with a tumor bearing wild-type K-ras did benefit from cetuximab. The mutation status of the K-ras gene had no influence on survival among patients treated with best supportive care alone. (ClinicalTrials.gov number, NCT00079066.)

/pdf/k-ras-mutations-and-benefit-from-cetuximab-in-advanced-8o4hhi5ipn.pdf

K-ras mutations and benefit from cetuximab in advanced colorectal cancer.

Purpose Panitumumab, a fully human antibody against the epidermal growth factor receptor (EGFR), has activity in a subset of patients with metastatic colorectal cancer (mCRC). Although activating mutations in KRAS, a small G-protein downstream of EGFR, correlate with poor response to anti-EGFR antibodies in mCRC, their role as a selection marker has not been established in randomized trials. Patients and Methods KRAS mutations were detected using polymerase chain reaction on DNA from tumor sections collected in a phase III mCRC trial comparing panitumumab monotherapy to best supportive care (BSC). We tested whether the effect of panitumumab on progression-free survival (PFS) differed by KRAS status. Results KRAS status was ascertained in 427 (92%) of 463 patients (208 panitumumab, 219 BSC). KRAS mutations were found in 43% of patients. The treatment effect on PFS in the wild-type (WT) KRAS group (hazard ratio [HR], 0.45; 95% CI: 0.34 to 0.59) was significantly greater (P .0001) than in the mutant group (HR, 0.99; 95% CI, 0.73 to 1.36). Median PFS in the WT KRAS group was 12.3 weeks for panitumumab and 7.3 weeks for BSC. Response rates to panitumumab were 17% and 0%, for the WT and mutant groups, respectively. WT KRAS patients had longer overall survival (HR, 0.67; 95% CI, 0.55 to 0.82; treatment arms combined). Consistent with longer exposure, more grade III treatment-related toxicities occurred in the WT KRAS group. No significant differences in toxicity were observed between the WT KRAS group and the overall population. Conclusion Panitumumab monotherapy efficacy in mCRC is confined to patients with WT KRAS tumors. KRAS status should be considered in selecting patients with mCRC as candidates for panitumumab monotherapy.

/pdf/wild-type-kras-is-required-for-panitumumab-efficacy-in-44cqqe1bte.pdf

Wild-type KRAS is required for panitumumab efficacy in patients with metastatic colorectal cancer

Functional activation of growth factors and receptors of the epidermal growth factor receptor (EGFR) family occurs in most epithelial-cell cancers, rendering EGFR a target for cancer treatment. This article discusses the mechanisms of action of EGFR inhibitors, their anticancer activity, and clinical issues concerning their use in the treatment of patients with cancer.

https://www.nejm.org/doi/pdf/10.1056/NEJMra0707704

EGFR Antagonists in Cancer Treatment

Purpose The addition of cetuximab to irinotecan, fluorouracil, and leucovorin (FOLFIRI) as first-line treatment for metastatic colorectal cancer (mCRC) was shown to reduce the risk of disease progression and increase the chance of response in patients with KRAS wild-type disease. An updated survival analysis, including additional patients analyzed for tumor mutation status, was undertaken. Patients and Methods Patients were randomly assigned to receive FOLFIRI with or without cetuximab. DNA was extracted from additional slide-mounted tumor samples previously used to assess epidermal growth factor receptor expression. Clinical outcome according to the tumor mutation status of KRAS and BRAF was assessed in the expanded patient series. Results The ascertainment rate of patients analyzed for tumor KRAS status was increased from 45% to 89%, with mutations detected in 37% of tumors. The addition of cetuximab to FOLFIRI in patients with KRAS wild-type disease resulted in significant improvements in overall survival (median, 23.5 v 20.0 months; hazard ratio [HR], 0.796; P .0093), progression-free survival (median, 9.9 v 8.4 months; HR, 0.696; P .0012), and response (rate 57.3% v 39.7%; odds ratio, 2.069; P .001) compared with FOLFIRI alone. Significant interactions between KRAS status and treatment effect were noted for all key efficacy end points. KRAS mutation status was confirmed as a powerful predictive biomarker for the efficacy of cetuximab plus FOLFIRI. BRAF tumor mutation was a strong indicator of poor prognosis. Conclusion The addition of cetuximab to FOLFIRI as first-line therapy improves survival in patients with KRAS wild-type mCRC. BRAF tumor mutation is an indicator of poor prognosis.

Cetuximab Plus Irinotecan, Fluorouracil, and Leucovorin As First-Line Treatment for Metastatic Colorectal Cancer: Updated Analysis of Overall Survival According to Tumor KRAS and BRAF Mutation Status

KRAS wild-type state predicts survival and is associated to early radiological response in metastatic colorectal cancer treated with cetuximab

4132 Background: A recent study has shown that the presence of a KRAS mutation is associated with the absence of objective response to cetuximab (CTX) in advanced colorectal cancers (mCRC). Our hyp...

KRAS mutations preclude tumor shrinkage of colorectal cancers treated with cetuximab

4064 Background: DUSPs dephosphorylate P-MAPK and are activated as a negative feedback loop upon RTK signaling. Higher expression of DUSP 4 & 6 is also found in cells with constitutive Erk activati...

DUSPs as markers of MEK/Erk activation in primary colorectal cancer

De Roock, Wendy ; Janssens, Marc ; Biesmans, Bart ; Jacobs, Bart ; De Schutter, Jef ; et. al. DUSP4 expression level in colorectal primaries predicts overall survival benefit in Kras wild-type and Kras mutant colorectal cancer after treatment with cetuximab for metastatic disease.20th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics ((Switzerland) Geneva, du 24/10/2008 au 28/10/2008). In: EJC Supplements, Vol. 6, no. 12, p. 33 (2008) http://hdl.handle.net/2078.1/59065 -DOI : 10.1016/ S1359-6349(08)72030-5

DUSP4 expression level in colorectal primaries predicts overall survival benefit in Kras wild-type and Kras mutant colorectal cancer after treatment with cetuximab for metastatic disease

M. Janssens

Papers

KRAS wild-type state predicts survival and is associated to early radiological response in metastatic colorectal cancer treated with cetuximab

KRAS mutations preclude tumor shrinkage of colorectal cancers treated with cetuximab

DUSPs as markers of MEK/Erk activation in primary colorectal cancer

DUSP4 expression level in colorectal primaries predicts overall survival benefit in Kras wild-type and Kras mutant colorectal cancer after treatment with cetuximab for metastatic disease