Is metastasectomy a worthy option? - the role of surgery in metastatic colon cancer to liver and lungs

Background: The role of surgery and metastasectomy is controversial in the treatment of stage IV colon cancer (CC). The aim of this study was to investigate the relationship between primary tumor resection (PTR) with metastasectomy and survival in patients diagnosed with metastatic CC. Methods: The National Cancer Data Base (NCDB) was retrospectively queried for patients diagnosed with colon adenocarcinoma from 2004 to 2013. Patient demographics, clinical characteristics, and shortterm outcomes were collected. Groups were generated based on if surgery was performed and, if so, was metastasectomy involved. Associations between groups were evaluated using Kruskal-Wallis and Pearson Chi-square tests. Overall survival (OS) was summarized using standard Kaplan-Meier methods. The association between surgical group and OS was evaluated using the log-rank test. Results: Of 31,172 patients, 13,214 (42.4%) had surgery while 17,958 (57.6%) did not. Among these, 81.3% of patients had liver metastases only, while 18.7% of patients had both liver and lung metastases. Median OS was 15.1 months (95% CI: 14.8 to 15.5 months) for the entire cohort. However, median OS was significantly better for those who had surgery (either PTR alone or FIR with metastasectomy) compared to those who did not (21.8 vs. 7.5 months, P<0.001). Patients who received PTR with metastasectomy had worse median OS (20.5 vs. 21.8 months, P=0.035) compared to those who only received PTR (P=0.211). Conclusions: PTR in select patients diagnosed with metastatic CC provides a remarkable improvement to survival rate. The role of metastasectomy remains controversial as no difference in survival outcomes exists between patients who received it and who did not.