Radiologic and pathologic response to neoadjuvant chemotherapy predicts survival in patients undergoing the liver-first approach for synchronous colorectal liver metastases.

PURPOSE: To investigate the short- and long-term outcomes of liver first approach (LFA) in patients with synchronous colorectal liver metastases (CRLM), evaluating the predictive factors of survival. METHODS: Sixty-two out of 301 patients presenting with synchronous CRLM underwent LFA between 2007 and 2016. All patients underwent neoadjuvant chemotherapy. After neoadjuvant treatment patients were re-evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST). Liver resection was scheduled after 4-6 weeks. Changes in non-tumoral parenchyma and the tumor response according to the Tumor Regression Grade score (TRG) were assessed on surgical specimens. Primary tumor resection was scheduled 4-8 weeks following hepatectomy. RESULTS: Five patients out of 62 (8.1%) showed "Progressive Disease" at re-evaluation after neoadjuvant chemotherapy, 22 (35.5%) showed "Stable Disease" and 35 (56.5%) "Partial Response"; of these latter, 29 (82%) showed histopathologic downstaging. The 5-year survival (OS) rate was 55%, while the 5-year disease-free survival (DFS) rate was 16%. RECIST criteria, T-stage, N-stage and TRG were independently associated with OS. Bilobar presentation of disease, RECIST criteria, R1 margin and TRG were independently associated with DFS. Patients with response to neoadjuvant chemotherapy had better survival than those with stable or progressive disease (radiological response 5-y OS: 65% vs. 50%; 5-y DFS: 20% vs. 10%; pathological response 5-y OS: 75% vs. 56%; 5-y DFS: 45% vs. 11%). CONCLUSIONS: LFA is an oncologically safe strategy. Selection is a critical point, and the best results in terms of OS and DFS are observed in patients having radiological and pathological response to neoadjuvant chemotherapy.