Trends and Comparative Effectiveness in Treatment of Stage IV Colorectal Adenocarcinoma

The management of patients with stage IV colorectal cancer is evolving. Primary treatment modalities include systemic chemotherapy, resection of the primary tumor, and, in select cases, resection of metastatic disease. Historically, stage IV disease was first managed with surgical resection to prevent complications such as obstruction, bleeding, and perforation prior to starting chemotherapy. The improved efficacy of newer oxaliplatin- and irinotecan-based chemotherapeutic regimens combined with the low incidence of tumor related complications has led surgeons and oncologists to question the utility and, when indicated, the timing of elective resection of the primary tumor in asymptomatic patients with metastatic disease. In addition, the indications for liver resection and liver ablative techniques for metastatic disease have increased.

In older patients, the morbidity and mortality following colon resection is significant. The role and timing of surgical resection relative to chemotherapy as well as aggressive management of liver metastases is even more controversial in this vulnerable population. Our first goal was to use Texas Cancer Registry (TCR) and Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data to evaluate the current management in older patients presenting with stage IV colorectal cancer, including receipt of chemotherapy, type of chemotherapy, resection of the primary tumor, and the management of liver metastases in a population-based, observational cohort. Next, in patients undergoing chemotherapy and/or elective resection of the primary tumor, we examined trends in the timing of chemotherapy and resection of the primary tumor and evaluated the comparative effectiveness when chemotherapy versus resection of the primary tumor was used as the initial treatment modality. Finally, we evaluated trends and outcomes in liver-directed therapy for metastatic disease in this population.