Perioperative Chemotherapy is Associated with Superior Overall Survival in Patients with Synchronous Colorectal Liver Metastases

Background. The sequence of localized and systemic treatment for colorectal liver metastases (CRLM) remains debated. Our objective is to analyze the effect of treatment sequence on overall survival (OS) in patients with CRLM using a large cancer database.Patients and Methods. The national cancer database (NCDB) was utilized to identify patients with stage IV colorectal cancer (CRC) diagnosed between 2004 and 2016. OS was analyzed using standard univariate and multivariate methods.Results. We identified 72,376 patients with synchronous CRLM, of whom 43,039 had liver-only metastases. Patients with liver-only CRLM had a median OS of 18.9 months, versus those with CRLM plus extrahepatic sites (11.3 months). In patients with liver-only CRLM, resection of both the primary and metastatic site was associated with median OS 38.9 months versus 30.2 months after resection of the metastatic site alone, and resection of the primary tumor alone (22.3 months, all p < 0.001). Receipt of perioperative chemotherapy correlated with a median OS of 44.7 months versus preoperative chemotherapy only (38.4 months) or postoperative chemotherapy only (27.9 months, all p < 0.001). Patients who received chemotherapy alone had a median OS of 16.4 months versus those who underwent resection without chemotherapy (9.5 months, p < 0.001).Conclusions. This study reveals a correlation between perioperative chemotherapy and superior OS in patients with liver-only CRLM, and shows that resection of the metastatic site was linked to better OS. Despite obvious cohort heterogeneity, the data can support a resection approach with additional, preferably peri- or preoperative systemic therapy for patients with CRLM.