Predictive model for survival after liver resection for noncolorectal liver metastases in the modern era: a Japanese multicenter analysis

Background: Survival benefit of liver resection for noncolorectal liver metastases (NCRLM) remains to be defined. Methods: This multicenter, retrospective cohort analysis included consecutive patients with NCRLM whose primary tumor and all metastases were treated with curative intent between 2000 and 2013. The primary endpoint was 5-year overall survival. Clinicopathological factors that affected prognoses were identified using multivariate Cox regression analyses and were included in a predictive model. Results: Data for 205 patients were analyzed. The three most common primary tumor sites were stomach (39%), pancreas (13%), and urinary tract (10%), with adenocarcinomas the main pathology (52%). R0 resection was achieved in 85%, and the overall survival at 5 years was 41%. In the multivariate analysis, synchronous liver metastases, R1/2 resection, and adenocarcinomas and other carcinomas (with gastrointestinal stromal tumors, neuroendocrine tumors G1/G2, and sarcomas set as the reference group) were independent negative indicators of overall survival. A predictive model effectively stratified the NCRLM patients into low-, intermediate-, and high-risk groups with overall 5-year survival rates of 63%, 38%, and 21%, respectively (P < 0.001). Conclusions: Patients who underwent curative resection for metachronous disease and favorable tumor pathology are expected to have better survival in the NCRLM cohort.