Clinical outcomes of neoadjuvant chemotherapy for resectable colorectal liver metastasis with intermediate risk of postoperative recurrence: A multi-institutional retrospective study.

Aims: Risk-scoring systems for colorectal liver metastasis (CRLM) after hepatectomy allow prognoses to be predicted preoperatively. We investigated the clinical outcomes of neoadjuvant chemotherapy for resectable CRLM according to patient risk status, aiming to determine the subgroup of patients who could benefit from neoadjuvant chemotherapy. Methods: In this multi-institutional retrospective analysis, the preoperative risk score was calculated from six previously reported factors: synchronous metastases, primary lymph node positivity, tumor number, largest tumor diameter, extrahepatic metastasis, and the preoperative carbohydrate antigen 19-9 level. Patients were divided into three groups according to their risk scores: low risk (score = 0), intermediate risk (score 1-10), and high risk (score ≥11). Overall and recurrence-free survival curves were calculated using the Kaplan-Meier method. After propensity-score matching in the intermediate-risk group, we compared clinicopathological features and outcomes. Results: There were 318 cases, from 20 institutions. The preoperative risk score could be calculated in 277 cases. There were 34, 192, and 51 patients in the low-, intermediate-, and high-risk groups, respectively. Intermediate-risk group patients who received neoadjuvant chemotherapy had significantly better recurrence-free survival than that of patients without neoadjuvant chemotherapy ( Conclusion: Neoadjuvant chemotherapy for resectable CRLM might prolong the recurrence-free survival period for intermediate-risk patients with preoperative risk scores in the range of 1-10, but the overall survival was not improved by neoadjuvant chemotherapy.