Role of pre-existing type 2 diabetes in colorectal cancer survival among older Americans: a SEER-Medicare population-based study 2002-2011.

Purpose: Type 2 diabetes mellitus (diabetes) is a common comorbid condition among older adult colorectal cancer (CRC) patients, yet its effects on CRC mortality have not been adequately examined. This study aims to investigate the association between pre-existing diabetes, with and without complications, and CRC mortality.

Methods: Medicare beneficiaries 67 years and older diagnosed with CRC between 2002 and 2011 were studied using the Surveillance, Epidemiology, and End Results (SEER)-Medicare datasets.