Treatments for Stage IV Colon Cancer and Overall Survival.

BACKGROUND:The role of primary tumor resection (PTR) for asymptomatic stage IV colon cancer with unresectable metastases remains unclear. Increasingly there has been a trend away from resection. The aim of this study was to examine trends in the treatment of stage IV colon cancers, impact of different treatments on long-term mortality, and factors associated with receipt of postoperative chemotherapy. METHODS:The 2006-2012 National Cancer Data Base was queried for stage IV colon cancer patients. Treatments were grouped into PTR and chemotherapy, PTR only, chemotherapy only, and no treatment. A descriptive analysis was performed examining patient and hospital characteristics associated with different treatments. A Cox regression analysis was used to assess the adjusted effect of different treatments on long-term survival. A multivariable logistic regression was used to examine factors associated with postoperative chemotherapy. RESULTS:Of 31,310 patients, who met inclusion criteria, 22% of the patients underwent PTR and chemotherapy, 37.5% received chemotherapy only, 11.9% underwent PTR, and 28.6% received no treatment. Patients who received no treatment had the highest hazard of death at 1, 3, and 5 y, followed by PTR only, and chemotherapy only compared with PTR combined with chemotherapy. Patients who were older and had more comorbidities were less likely to receive postoperative chemotherapy. CONCLUSIONS:Primary tumor resection in conjunction with postoperative chemotherapy among stage IV colon cancer patients with unresectable metastases was associated with a long-term survival benefit compared with other treatment options. Efforts should be made to increase the use of postoperative chemotherapy where feasible.