Efficacy of Adjuvant Chemotherapy Following Curative Resection of Colorectal Cancer Liver Metastases

Routine use of adjuvant chemotherapy (AC) following hepatectomy for colorectal liver metastases (CRLM) is not universally practiced because of the lack of supporting evidence. Therefore, we investigated the efficacy of AC following curative CRLM resection.Among the 742 patients who underwent their first hepatectomy for CRLM at our institution, 335 were stratified into surgery alone (SA; n=162) and AC (n=173) groups. Poor prognostic factors for SA were identified using multivariate logistic regression analysis. Propensity score matching was used to compare the clinical outcomes between SA and AC groups according to the number of prognostic factors.Multivariate analysis showed that preoperative carcinoembryonic antigen (CEA) levels (≥10 ng/ml; p=0.01), primary lymph node metastases (≥1; p=0.0001), and the number (n≥4; p=0.01) and maximum diameter (≥5 cm; p=0.00001) of CRLM tumours were independent poor prognostic factors for overall survival (OS) in the SA group. Patients with ≥3 risk factors were categorized as being high risk. After propensity score matching, the 5-year OS rate was significantly higher in the AC group (n=13) than that in the SA group (n=15; 47.9% vs. 7.3%; p=0.03) among high-risk patients.Adjuvant chemotherapy after curative CRLM resection may improve the prognosis of patients with three or more risk factors including preoperative CEA levels ≥10 g/ml, primary lymph node metastases ≥1, number (≥4) and maximum diameter (≥5 cm) of CRLM tumours.