Effect of tumor location in metastatic colorectal cancer to response anti-EGFR and anti-VEGF treatment: One center study.

Abstract

e15023 Background: Colorectal cancer is the one of the most common malignancy in western countries. In addition to standart treatment antiEGFR and antiVEGF agents have improved PFS and overall survival. Current studies showed that the colorectal cancers have heterogenous characteristics. The Colon is divided into two parts as a right and left colon according to embrological origin. Recent years supposed that right and left located colorectal tumors may not response samely to anti egfr and anti vegfr therapies. We performed a retrospective study in our clinic to answer this questions. Methods: Study Population and data collection: Between January 2005 and December 2016, all metastatic colorectal cancer patients (n = 285) who received anti-EGFR and anti- VEGF agent with chemotherapy on initial treatment at the Erciyes University Medical Oncology Department were retrospectively reviewed. We included patients with diagnosed metastatic colorectal cancer and who received at least 1 dose of antiEGFR-based or antiVEGFR-based triplet bio-chemotherapy as their first-line treatments. Study population was divided into two groups as right and left colon. Results: A total of 251 patients met the inclusion criteria: 55 patients classified as a right colon cancer (RCC) and 196 patients classified as a left colon cancer (LCC) . 16 patients in RCC group received anti-EGFR-based triplet and 39 patients in RCC group received antiVEGF-based triplet; 76 patients in LCC group received anti-EGFR-based triplet and 120 patients in LCC group received antiVEGF-based triplet as first-line bio-chemotherapy. There were no differences between the patients received antiEGFR and antiVEGF therapy in RCC group (PFS,antiEGFR vs anti VEGF, 7 vs 8 months,P = 0.378; OS, 21 vs 19 months, P = 0.876). There were no differences between the patients received antiEGFR and antiVEGF therapy in LCC group (PFS,antiEGFR vs anti VEGF, 10 vs 10 months,P = 0.202; OS, 27 vs 24 months, P = 0.656). Conclusions: Our study shows that there were no significiant difference between the metastatic colorectal cancer patients received antiEGFR and antiVEGF treatment in LCC and RCC.