Treatment of Stage IV Colon Cancer in the United States: A Patterns-of-Care Analysis

Background: National guidelines recommend chemotherapy as the mainstay of treatment for stage IV colon cancer, with primary tumor resection (PTR) reserved for patients with symptomatic primary or curable disease. The aims of this study were to characterize the treatment modalities received by patients with stage IV colon cancer and to determine the patient-, tumor-, and hospital-level factors associated with those treatments. Methods: Patients diagnosed with stage IV colon cancer in 2014 were extracted from the SEER Patterns of Care initiative. Treatments were categorized into chemotherapy only, PTR only, PTR + chemotherapy, and none/unknown. Results: The total weighted number of cases was 3,336; 17% of patients received PTR only, 23% received chemotherapy only, 41% received PTR + chemotherapy, and 17% received no treatment. In multivariable analyses, compared with chemotherapy only, PTR + chemotherapy was associated with being married (odds ratio [OR], 1.9), having bowel obstruction (OR, 2.55), and having perforation (OR, 2.29), whereas older age (OR, 5.95), Medicaid coverage (OR, 2.46), higher T stage (OR, 3.51), and higher N stage (OR, 6.77) were associated with PTR only. Patients who received no treatment did not have more comorbidities or more severe disease burden but were more likely to be older (OR, 3.91) and non-Hispanic African American (OR, 2.92; all P< .05). Treatment at smaller, nonacademic hospitals was associated with PTR (+/- chemotherapy). Conclusions: PTR was included in the treatment regimen for most patients with stage IV colon cancer and was associated with smaller, nonacademic hospitals. Efforts to improve guideline implementation may be beneficial in these hospitals and also in non-Hispanic African American and older populations.