Tumor response and outcome after reverse treatment for patients with synchronous colorectal liver metastasis: a cohort study

BACKGROUND: The reverse treatment of patients with synchronous colorectal liver metastases (CRLM) is a sequential approach with systemic chemotherapy first, followed by liver resection, and finally, primary tumor resection. The aim of this study was to assess the feasibility, the radiological and pathological tumor response to neoadjuvant therapy, recurrence rates and long-term survival after reverse treatment in a cohort study. METHODS: Data from patients with CRLM who underwent a reverse treatment from August 2008 to October 2016 were extracted from our prospective hepato-biliary database and retrospectively analyzed for response rates and survival outcomes. Radiological tumor response was assessed by RECIST (Response Evaluation Criteria In Solid Tumor) criteria and pathological response according to TRG (Tumor Regression Grade). Disease-free and overall survival were estimated with Kaplan-Meier survival curves. RESULTS: There were 44 patients with 19 rectal and 25 colonic tumors. The reverse treatment was fully completed until primary tumor resection in 41 patients (93%). Radiological assessment after chemotherapy showed 61% of complete/partial response. Pathological tumor response was major or partial in 52% of patients (TRG 1–3). Median disease-free survival after primary tumor resection was 10 months (95% CI 5–15 months). Disease-free survival at 3 and 5 years was 25% and 25%, respectively. Median overall survival was 50 months (95% CI 42–58 months). Overall survival at 3 and 5 years was 59% and 39%, respectively. CONCLUSION: The reverse treatment approach was feasible with a high rate of patients with complete treatment sequence and offers promising long-term survival for selected patients with advanced simultaneous colorectal liver metastases.