Trends in treatment and survival in older patients presenting with stage IV colorectal cancer.

Introduction: Trends in the use of modern chemotherapeutic regimens, primary tumor resection, and the timing of chemotherapy and resection in older patients with stage IV colorectal cancer have not been evaluated.

Methods: We used Cancer Registry- and Medicare-linked data (2000-2009) to describe time trends in resection of the primary tumor and receipt of chemotherapy in patients ≥ 66 presenting with stage IV colorectal cancer (N = 16,168).

Results: The mean age was 77.8 ± 7.3 years; 53.8 % were women and 82.9 % were white. Primary cancer sites were colon in 83.4 % and rectum in 16.6 %. Resection of the primary tumor decreased from 64.6 to 57.1 % (P < 0.0001) from 2001 to 2009. Systemic chemotherapy was given to 45.1 % of the patients. While the use of chemotherapy was stable over time (P = 0.48), the use of modern regimens containing oxaliplatin or irinotecan increased from 40.9 to 75.4 % (P < 0.0001). Bevacizumab use increased from 0.10 to 54.2 % (P < 0.0001). Survival improved by 4 % per year even after controlling for treatment and tumor location (HR = 0.96, 95 % CI 0.95-0.97).

Conclusions: Survival in older patients with stage IV disease is improving over time. Surgical resection is still performed in the majority of patients. Resection rates decreased while modern chemotherapy was rapidly adopted perhaps suggesting a shift in practice patterns.