Patterns of care in patients with asymptomatic stage IV colon cancer: A population-based analysis

Currents guidelines recommend chemotherapy with or without biologic agents for asymptomatic stage IV colon cancer treatment, whereas primary tumor resection is reserved for symptomatic tumors or resectable metastases. However, US treatment patterns are understudied. Our study aims to identify real-world treatment patterns for asymptomatic metastatic colon cancer.

Adults with asymptomatic metastatic colon cancer were identified in the 2014 Surveillance, Epidemiology, and End Results Patterns of Care database and categorized into 6 groups: chemotherapy with or without biologic agents, chemotherapy with or without biologic agents with primary tumor resection and metastasectomy, chemotherapy with or without biologic agents and primary tumor resection alone, primary tumor resection only, no treatment, or other treatments. Multinomial logistic regression was used to examine factors associated with receiving each treatment modality. Cox proportional hazard models were used to assess the relationships between treatments and survival.

Among 1,717 weighted patient cases, 28% received chemotherapy with or without biologic agents, 23% chemotherapy with or without biologic agents with primary tumor resection, 12% chemotherapy with or without biologic agents with primary tumor resection and metastasectomy, 12% primary tumor resection only, 23% no treatment, and 2% other treatment. Younger patients were more likely to receive chemotherapy with or without biologic agents with primary tumor resection and metastasectomy than chemotherapy with or without biologic agents alone (odds ratio, 3.32; 95% confidence interval, 1.3-8.6) and less likely to undergo no treatment (odds ratio, 0.05; 95% confidence interval, 0.02-0.17). Patients treated by chemotherapy with or without biologic agents with primary tumor resection and metastasectomy had the greatest median survival of 61 months, whereas those with no treatment had a 1-month median survival.

Almost one quarter of patients with asymptomatic stage IV colon cancer received no treatment. Meanwhile, 12% of patients underwent curative systemic and surgical treatment, which was associated with a median survival of 5 years, validating reported outcomes of this approach by institutional studies. These data provide an important benchmark for future interventions pertaining to asymptomatic patients with stage IV colon cancer.