The Prognostic Significance of a Histological Response to Preoperative Chemotherapy in Patients With Synchronous Colorectal Liver Metastases

Abstract

Objective: Preoperative chemotherapy (PC) for colorectal liver metastasis (CRLM) is widely used to improve prognosis, but its clinical benefit has not been fully established. This study aimed to assess the effectiveness of PC for synchronous CRLM and the correlation between the histological response to PC and survival. Summary of Background Data: We enrolled 69 patients who underwent initial hepatectomy for synchronous CRLM between 2004 and 2018 at Gifu University Hospital. Methods: We retrospectively analyzed the clinicopathological factors and outcomes of 69 patients who underwent hepatectomy after receiving PC (PC group: n = 43) or who underwent upfront hepatectomy (non-PC group: n = 26). In the PC group, the patients were divided into the Grade 1 (n = 27) and Grade 2/3 (n = 16) groups according to their histological responses to PC. Results: The median survival and 5-year overall survival (OS) rates were 80.9 months and 61.5%, respectively, in the PC group and 71.7 months and 61.5%, respectively, in the non-PC group ( P = 0.867). Regarding recurrence-free survival (RFS) and remnant liver-RFS, there were no significant differences between the two groups ( P = 0.087 and 0.291). However, in a subgroup analysis, the median 5-year OS, RFS, and remnant liver RFS were significantly longer in the Grade 2/3 than Grade 1 group ( P = 0.008, P = 0.002, and P < 0.001, respectively). Conclusions: Some patients benefit from PC, and the histological response to PC had prognostic significance for patients with synchronous CRLM.