596PTHERAPEUTIC TACTICS FOR RESECTABLE COLORECTAL CANCER METASTASES IN THE LIVER EXHIBITING POOR PROGNOSIS

ABSTRACT Aim: The current study aimed to improve treatment effects for patients with resectable metastases of colorectal cancer in the liver exhibiting a poor prognosis. Methods: Overall 437 patients were enrolled with metastatic colorectal cancer in the liver exhibiting at least one adverse factor of long-term prognosis: multiple metastases, bilobar liver metastases, large-size metastases, the presence of extrahepatic metastases, etc. Combined treatment was performed for 339 (78%) patients: combined treatment with adjuvant systemic chemotherapy (163 patients), combined treatment with perioperative systemic chemotherapy (54 patients), or combined treatment of perioperative regional chemotherapy (122 patients). Surgical treatment was performed in 66 (15 %) patients. The remaining group of 32 (7%) patients with resectable metastases who received only systemic chemotherapy were considered separately. All liver resections were extensive due to the widespread metastases. Results: Mortality among operated patients was 4%. The complication rate stood at 56%. Postoperative mortality and complications in the two groups were not statistically different, nor was the intraoperative blood loss in the two groups. Adding bevacizumab to preoperative chemotherapy did not increase blood loss. After combined treatment with adjuvant chemotherapy the 5-year survival was 26 ± 4%, significantly outperforming the 5-year survival rate after surgery (17 ± 5%), as well as drug treatment (5-year survival has not been reached), and also the combined treatment with perioperative systemic chemotherapy (13 ± 5%). Survival was also superior to the 5-year survival after combined treatment with perioperative regional chemotherapy (20 ± 5 %), although not statistically so. Conclusions: The study demonstrates the benefits of combined treatment with adjuvant systemic chemotherapy for resectable colorectal cancer metastases in the liver exhibiting poor prognosis. For initially unresectable liver metastases in the absence of extrahepatic manifestations of the disease, treatment should begin with regional chemotherapy and biotherapy, whereas for initially unresectable metastases with extrahepatic manifestations of the disease, treatment should begin with systemic chemotherapy. Disclosure: All authors have declared no conflicts of interest.