P-0244 - Surgical Treatment of Metastases and Its Impact on Prognosis in Patients with Metastatic Colorectal Carcinoma

Abstract

Background: Approximately one quarter of patients with colorectal carcinoma have distant metastases at initial diagnosis and almost 50% will develop them during the disease course. Only radical surgical resection of metastases improves the clinical outcome and offers the chance of long-term survival. Initially unresectable metastases can become resectable after downsizing with systemic therapy. Methods: Our analysis included 21 patients older than 18 years of age (10 men, 11 women) with metastatic colorectal carcinoma (mCRC) who underwent resection/ ablation of metastases. 14 patients had resection at initial diagnosis of metastatic disease and 7 patients achieved operability of metastases after the systemic treatment. The aim of our analysis was to evaluate following parameters: age structure, localization of primary tumor and metastases, disease free survival (DFS), progression free survival (PFS) and overall survival (OS). We also assessed frequency of KRAS and BRAF mutations in the primary tumor and importance of BRAF as negative prognostic factor. Patients have been treated at the St. Elizabeth Cancer Institute in Bratislava since 2006 and the results were evaluated in January 2013. Results: The median age of patients was 59 years. Primary tumor was most frequently localized in colon sigmoideum. Typical localization of metastatic spread was liver observed in 14 patients. 1 patient had metastases in lungs, 2 patients had combination of hepatic and extrahepatic metastases and 4 patients had metastases in other regions. 12 patients were already diagnosed with stage IV colon cancer, 9 patients underwent adjuvant therapy in the past and developed metastases later with median DFS of 11 months. In median follow-up of 47 months (range 14-61 months) 17 patients experienced disease progression and 13 patients died. Median PFS after surgical resection of metastases was 17 months (95% CI 13.88-20.12) and median OS was 48 months (95% CI 38.78-57.23). 7 patients who had only solitary metastasis (in liver) reached better median PFS (18 months; 95% CI 15.43-20.57) and median OS (51 months; 95% CI 25.76-76.24) compared to patients with 2 and more metastases who had median PFS of 14 months (95 % CI 10.55-17.45) and median OS of 45 months (95% CI 19.61-70.39). KRAS mutation was detected in 47.6% of patients and BRAF mutation in 9.5% of patients. Patients with BRAF mutation had worse median PFS (10 months) and median OS (22 months) compared to patients with BRAF wild-type who had median PFS of 17 months and median OS of 51 months. Conclusion: These data suggest that resection/ablation of metastases significantly improves the prognosis of patients with mCRC. All patients with mCRC should by evaluated by multidisciplinary team and surgical treatment has to be always considered in appropriate selected patients. Our results also indirectly support the notion that mutated BRAF has a strong negative prognostic significance.