Effect of Cetuximab Combined with Chemotherapy in Treating Recurrent and Metastatic Colorectal Cancer: A Real-World Case Series

Introduction: Recurrent and metastatic colorectal cancer (mCRC) continues to carry a poor prognosis despite recent advances in surgical techniques, chemotherapy, and targeted therapies. Cetuximab, a monoclonal antibody targeting EGFR, is commonly used in mCRC, especially in patients with wild -type RAS and BRAF and proficient mismatch repair. However, its efficacy and optimal timing remain debated due to variability in clinical outcomes and toxicity profiles. This retrospective study evaluates the effectiveness and safety of cetuximab -based regimens in Indian patients with recurrent and metastatic colorectal cancer. Methods: Clinical data from 30 patients with confirmed recurrent or metastatic CRC treated between January 2015 and December 2020 were retrospectively reviewed. All patients had wild -type KRAS and received cetuximab -based chemotherapy. Outcomes assessed included overall survival (OS), progressionfree survival (PFS), response rates, and treatment -related adverse events. Results: The median age was 58 years; 83.3% were male.According to AJCC staging, 28 patients (93.3%) had Stage IV disease, and 2 (6.7%) had recurrent disease.ECOG performance status was 1 in 46.7% and 2 in 53.3%.Most had left -sided tumors (73.3%), while 20% had right -sided, and 6.7% had transverse colon involvement.Regarding chemotherapy backbones, 56.7% received cetuximab with 5 -FU -based regimens, 16.6% with capecitabine, and others with methotrexate, paclitaxel -carboplatin, or cetuximab monotherapy.Cetuximab was used in the 1st or 2nd line in 43.3% and in later lines in 56.7%.The median OS was 33 months, with a 2 -year OS rate of 76.7%.Median PFS was 3 months, and the 6 -month PFS rate was 36.7%.Partial responses were observed in 40%, stable disease in 13.3%, and progressive disease in the remainder.ORR at first follow -up was 36.7%, and DCR was 50%.Multivariate analysis indicated better OS and PFS in patients with recurrent disease and those receiving cetuximab earlier in treatment.Conclusion: Cetuximab -based chemotherapy demonstrates favorable outcomes in Indian patients with recurrent and mCRC, particularly when administered early in the treatment course.The therapy is associated with acceptable toxicity and improved survival in select subgroups.