e15009 Background: Colorectal cancer is a major cause of mortality worldwide. Survival has been improved by usage of bevacizumab. Our study aimed to analyze survival and prognostic factors in metastatic colorectal cancer patients treated with first-line bevacizumab. Methods: Files of patients were examined retrospectively and 360 patients treated with first-line bevacizumab were included. Data regarding age, gender, family history, location of the primary, histopathology, KRAS status, surgery and chemotherapy were acquired from the files. Overall response rates (ORR) to chemotherapy, progression and exitus dates or dates of last examination were recorded. Median progression-free and overall survival (PFS and OS) were calculated. Survival was analyzed with Kaplan-Meier method. Log-rank test and Cox regression model were used for univariate and multivariate analysis, respectively. Results: 201 (%55,8) of the patients were male and 159 (%44,2) were female. Median age at the time of the diagnosis was 59.5. 260 patients (%72,2) had initially stage IV disease. KRAS was mutant in 125 patients (%34,7). Median PFS was 8.5 months, median OS was 25.3 months and ORR was %51,4. Median PFS was 8.2 and 9.5 months, median OS was 30.4 and 28.1 months, ORR was %62,6 and %58.4 in KRAS wild type and mutant groups, respectively. In patients with left colon cancer median PFS and OS (9.6 and 27.1 months) were superior compared to patients with right colon cancer (7.3 and 19.4 months) (p = 0.005 and 0.016, respectively). Location of the primary, histopathologic grade, primary surgery, metastasectomy and KRAS status affected overall survival significantly (p < 0.05) in univariate analysis. In multivariate analysis, histopathologic grade (p = 0.034) and metastasectomy (p = 0.001) were independent prognostic factors. Conclusions: In our study, response rates and survival of metastatic colorectal cancer patients treated with first-line bevacizumab were similar to previous studies. Left colon cancer patients had superior median PFS and OS compared to right colon cancer patients as shown in recent studies. Histopathologic grade and metastasectomy were independent prognostic factors in correlation with literature.
Retrospective analysis of KRAS status in metastatic colorectal cancer patients: a single-center feasibility study
