Reconsideration of the Indications for Adjuvant Chemotherapy for Liver Metastases from Colorectal Cancer After Initial Hepatectomy

Background. The effectiveness of perioperative adjuvant chemotherapy for colorectal cancer liver metastasis (CRLM) remains a matter of debate. Despite the lack of clear evidence supporting its effectiveness after curative hepatectomy, adjuvant chemotherapy has been widely used clinically. The purpose of this study was to clarify the indications for adjuvant chemotherapy in order to develop an appropriate treatment strategy for CRLM. Methods. The clinicopathological factors of 110 patients who underwent initial hepatectomy for CRLM between April 2000 and March 2010 were retrospectively analyzed. The prognostic factors of CRLM were identified and then CRLM was stratified according to the number of prognostic factors into the high-score group (H-group: score 2 or 3) and the low-score group (L-group: score 0 or 1), and the effectiveness of adjuvant chemotherapy was analyzed in each group. Results. Multivariate analysis identified pT4 (p = 0.0047), lymph node metastasis in colorectal cancer (CRC) (p = 0.0165), and H2-classification (p = 0.0051) as factors related to a poor prognosis. The overall 5-year survival rate was markedly higher in the L-group (68 %) than in the H-group (26 %, p < 0.0001). Moreover, in the L-group, patients who did not receive adjuvant chemotherapy had the same prognosis as those who received adjuvant chemotherapy. As for recurrence, tumor relapse more often was treated by resection in the L-group than in the H-group (p = 0.0339). Conclusions. Adjuvant chemotherapy did not improve overall survival and disease-free survival in patients with no more than two factors of the H2-classification, invasion depth pT4, and lymph node metastasis in CRC.