EGFR-targeted Treatments in Patients with Metastatic Colorectal Cancer: Experience of Panitumumab.

e15028 Background: Overall survival times have been exceeded three years by the targeted treatments in metastatic colorectal cancer (MCC) . The sequence of these agents and the possible side effects constitute our discussions. We aimed to investigate the efficacy and tolerability of panitumumab use in this study. Methods: In this study 168 MCC patients from 15 different centers that were treated with panitumumab in first or second line settings were evaluated respectively. Progression free survival (PFS) and overall survival(OS) time were calculated in case of the patients treated with targeted treatments in first line setting. Results: The median follow-up time was 12(3-82) months. The median age was 60 (24-86) years and 36 % of the patients were female. Panitumumab as a component of first line treatment was used in 66 % of the patients. Median 6 (1-18) cycles treatment were given to the patients as first line chemotherapy. The median PFS was 11 (SE:2; 95% CI: 7-15) months in patients treated with panitumumab while 12 (SE:1; 95% CI: 10-14) months in patients treated with bevacizumab containing regimens as first line treatment (p:0.836). The median OS was 32 (SE:12; 95% CI: 7-56) months in patients treated with panitumumab containing regimen and the median OS has not been reached in bevacizumab group (p: NS). In univariate analysis, female gender and left-sided colon tumors have favorable PFS (p:0.030 and p:0.023 respectively). No difference between bevacizumab or panitumumab containing regimen in right- sided tumors have observed (p:0.812). But in left-sided tumors, the panitumumab containing regimens have favorable PFS (8 vs 13 months. p:0.023). Grade 2 or higher skin rash was observed in 49% . Diarrhea in 38%, neuropathy in 30%, different hematologic toxicity in 14% and infusion reaction in 2.2% of the patients were detected. The skin rash was associated to panitumumab containing regimen (p:0.000). Other toxicity frequencies were not statistically significant in both groups. Conclusions: Compilation of current life data in MCC treatment will reveal the efficacy and tolerability in our daily practice beyond as data in clinical trials. These data together with more experience will guide the optimization of the treatments.