Treatments for Stage IV Colon Cancer and Overall Survival

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.

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.

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.

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.