Yukihide Kanemitsu, Yasuhiro Shimizu, Junki Mizusawa, Yoshitaka Inaba, Shunsuke Tsukamoto, A. Takashima, Masayuki Ohue, Koji Komori, Akio Shiomi, M. Shiozawa, Yusuke Suwa, Takeshi Suto, Yusuke Kinugasa, Yasumasa Takii, Hiroyuki Bando, Takaya Kobatake, Masafumi Inomata, Yasuhiro Shimada, H. Katayama, Haruhiko Fukuda, JCOG Colorectal Cancer Study Group
JCOG0603 demonstrated improved disease-free survival (DFS) with adjuvant mFOLFOX6 after hepatectomy compared with hepatectomy alone in colorectal liver-only metastasis (CRLM), but the overall survival (OS) data were immature. Here, we report OS after long-term follow-up. Eligible patients with colorectal adenocarcinoma and an unlimited number of liver metastases were randomized to adjuvant mFOLFOX6 or hepatectomy alone. DFS was the primary endpoint, and OS was a secondary endpoint. Between March 2007 and January 2019, 151 and 149 patients were randomized to adjuvant chemotherapy and hepatectomy alone, respectively. At a median follow-up of 7.7 years for disease-free surviving patients, 54 (35.8%) and 51 (34.2%) patients had died in the respective arms, (hazard ratio [HR], 1.07 [95% CI, 0.73 to 1.57]). Five-year OS was 73.4% (95% CI, 65.5 to 79.7) and 80.1% (95% CI, 72.6 to 85.7) and 7-year OS was 69.4% (95% CI, 61.2 to 76.2) and 72.4% (95% CI, 64.2 to 79.1), respectively. One patient in the adjuvant chemotherapy arm possibly died of protocol treatment-related toxicity, and one in the hepatectomy-alone arm died of post-protocol treatment complications. Five-year DFS was respectively 49.7% (95% CI, 41.5 to 57.3) and 40.5% (95% CI, 32.5 to 48.3) in the adjuvant chemotherapy and hepatectomy-alone arms (HR, 0.72 [95% CI, 0.54 to 0.97]). Long-term OS did not differ with adjuvant mFOLFOX6 compared with hepatectomy alone in resectable CRLM. Adjuvant mFOLFOX6 may delay recurrence but did not improve long-term survival.