Analysis of Nonsurgical Treatment Options for Metastatic Rectal Cancer.

INTRODUCTION: Using a large national registry, we investigated patterns of care and overall survival (OS) for metastatic rectal cancer patients treated with chemotherapy or radiotherapy (RT), or with a multimodal approach. PATIENTS AND METHODS: Adult patients with metastatic rectal cancer who did not undergo resection diagnosed from 2004 to 2014 were included. Kaplan-Meier, log-rank, and Cox regression analyses were performed. RESULTS: We identified 2385 patients. Of these, 1020 patients (43%) received chemotherapy alone, 228 (10%) received RT alone, 850 (36%) received chemotherapy and RT, and 287 (12%) received no treatment. Receipt of chemotherapy alone increased over the study period, and receipt of chemoradiotherapy decreased (P < .01). The only factor predictive of receiving any RT on multivariate analysis was clinical stage T3 disease. Factors predictive of OS on multivariate analysis included receipt of chemotherapy, Hispanic race, income greater than $46,000, and presence of lung metastasis. The OS for patients treated with chemotherapy and RT was not significantly different than chemotherapy alone. Five-year OS with chemotherapy alone, RT alone, chemoradiotherapy, and no treatment were, respectively, 84%, 56%, 79%, and 46%. CONCLUSION: Metastatic rectal cancer patients with T3 tumors were more likely to receive RT. Local RT does not improve survival for patients with metastatic rectal cancer who do not also undergo surgery. The use of chemotherapy alone for metastatic rectal cancer is increasing, and chemotherapy is associated with higher OS compared to no treatment and RT alone. This remained true even in patients older than 80 years.