Abstract

Background: The presence of a Kristen-Rat Sarcoma (KRAS) and NRAS activating mutations in metastatic CRC (mCRC) were significantly associated with absence of response to agents targeting epidermal growth factor receptor(EGFR). Our study aims to describe the pattern of KRAS and NRAS mutations and effectiveness of Cetuximab- and Bevacizumab-containing regimens in mCRC patients. Methodology: In this retrospective observational study, a total of 156 mCRC patients data were evaluated, out of which 124 patient’s KRAS and NRAS mutation status was known. We evaluated demographic and clinical characteristics and progression-free survial(PFS) of mCRC patients treated with cetuximab-or bevacizumab-containing regimens. Results: Median age was 56 yrs(18-78yrs). Total 124 patient’s mutation status was known,out of which 34 (27%) were positive for KRAS and 4 (3%) for NRAS. Overall, there were 83 (67%) males and 41 (33%) females. In KRAS positive group, 26 (76%) were males and 08 (24%) females. Bevacizumab treated patients(69.2%) mostly received oxaliplatin-based backbone, whereas, cetuximab treated pateints(56.8%) mostly received irinotecan-based chemotherapy. There was no significant difference in PFS between cetuximab-and bevacizumab-based treated patients. Conclusion: Efforts to obtain tissue samples should be encouraged for KRAS and NRAS mutation testing in mCRC patients to provide a molecular basis to treat with available anti-EGFR monoclonal antibodies in mutation wild-type patients.

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