The Clinical Risk Score Predicts the Effectiveness of Adjuvant Chemotherapy for Colorectal Liver Metastasis

Hepatectomy is the most effective treatment for patients with colorectal liver metastasis (CRLM). However, the procedure is also associated with a high risk of recurrence, and adjuvant chemotherapy for postoperative recurrence remains controversial. We investigated the efficacy of adjuvant chemotherapy for CRLM with the clinical risk score (CRS) proposed by Fong et al. Patients with CRLM who were treated, without preoperative chemotherapy, between 1992 and 2012 were classified as having low CRS (score of 0-1), intermediate CRS (2-3), or high CRS (4-5). The efficacy of adjuvant chemotherapy was retrospectively analyzed for each CRS subgroup. Of the 161 patients who underwent hepatectomy, 100 received adjuvant chemotherapy (group A) and 61 did not (group N). For intermediate CRS, 5-year disease free survival (DFS) was significant different between the groups (group A: n = 61; 33.9 % vs. group N: n = 39; 23.2 %, P = 0.008) and 5-year overall survival (OS) of group A was higher than group N (53.5 vs. 36.5 %, P = 0.048), respectively. For both low CRS and high CRS, 5-year DFS and OS were similar between the groups. Multivariate analysis of DFS identified prognostic factors as major resection for low CRS (P = 0.02) and adjuvant chemotherapy for intermediate CRS (P = 0.015). Similarly, multivariate analysis of OS identified major resection for low CRS (P = 0.05) and adjuvant chemotherapy for intermediate CRS (P = 0.05). High CRS was not identified prognostic factor. Adjuvant chemotherapy for CRLM was effective in intermediate CRS patients. In low CRS patients, adjuvant chemotherapy may not be necessary, but adequate surgical resection is important.