0000000000932060
AUTHOR
Gianni Simone
Heterogeneity of KRAS, NRAS, BRAF and PIK3CA mutations in metastatic colorectal cancer and potential effects on therapy in the CAPRI GOIM trial
Background: Evidence suggests that metastatic colorectal carcinoma (mCRC) has a high level of intratumor heterogeneity. We carried out a quantitative assessment of tumor heterogeneity for KRAS, NRAS, BRAF and PIK3CA mutations, in order to assess potential clinical implications. Patients and methods: Tumor samples (n = 182) from the CAPRI-GOIM trial of first-line cetuximab + FOLFIRI in KRAS exon-2 wild-type mCRC patients were assessed by next-generation sequencing that allows quantitative assessment of mutant genes. Mutant allelic frequency was normalized for the neoplastic cell content and, assuming that somatic mutations usually affect one allele, the Heterogeneity Score (HS) was calculate…
KRAS mutations and sensitivity to anti-EGFR monoclonal antibodies in metastatic colorectal carcinoma: an open issue.
Background: Cetuximab and panitumumab, mAbs targeting EGFR, are registered for metastatic colorectal carcinoma (mCRC) patients whose tumors express EGFR as determined by immunohistochemistry. However, this method is not predictive of treatment efficacy. KRAS, the human homolog of the Kirsten rat sarcoma-2 virus oncogene, encodes a small G-protein that functions downstream of EGFR-induced signalling. Objective/Methods: To examine KRAS mutations as predictive factors of response to anti-EGFR mAbs using recently published data. Results/conclusions: Several retrospective studies show that efficacy of these mAbs is confined to patients with wild type KRAS and genotyping of tumors should be consi…