Trends and predictors of resection of the primary tumor for patients with stage IV colorectal cancer.

Background and Objectives: Over 130,000 patients are diagnosed with colorectal cancer annually, with approximately 20% presenting with unresectable metastatic disease. Recent consensus guidelines recommend against primary tumor resection for asymptomatic patients with unresectable metastases. Our goal was to examine the trends and predictors of surgical resection.
Methods: Cases of colorectal cancer with synchronous metastases diagnosed between 1988-2010 were identified using the Surveillance, Epidemiology and End Results (SEER) Database. Associations between resection and clinicopathologic variables were sought using univariate and multivariate logistic regression.
Results: Overall, 68% of patients with synchronous metastatic colorectal cancer underwent primary tumor resection. Resection rates were as high as 76% in the earliest time period (1988-1992) and steadily dropped to 60% in the most recent period (2008-2010). Socioeconomic factors associated with resection on univariate analysis included age, race, gender, marital status, insurance status, and geographic region. Clinicopathologic characteristics associated with resection included tumor location, grade, size, and CEA level. In the multivariate model, gender, geographic region, insurance status, tumor location, grade and CEA level were independent predictors of primary tumor resection.
Conclusions: Surgical resection of the primary site remains common practice for patients with synchronous metastatic colorectal cancer. Treatment disparities are associated with socioeconomic as well as clinicopathologic factors.
(© 2015 Wiley Periodicals, Inc.)