A study using data from the Michigan Tumor Registry and the Centers for Medicare and Medicaid Services showed that elderly Medicaid-insured patients in the state are less likely to initiate or complete chemotherapy for colorectal cancer compared with Medicare-insured patients. The results were published in the March 10 Archives of Internal Medicine. Previous studies have shown that Medicaid-insured patients have worse survival rates for colorectal cancer, but it had not been known if they receive less treatment than patients with other forms of insurance.

The investigators collected data from 4,765 patients aged 65 or older who were diagnosed with colorectal cancer between January 1997 and December 2000 and insured through Medicaid, Medicare, or both. In addition to data on chemotherapy initiation and completion, the investigators compared whether patients were evaluated by an oncologist, subsequently hospitalized, and experienced comorbidities; demographic variables including age, race, sex, household income, and whether patients lived in a metropolitan, urban, or rural area were also studied.

Patients insured through Medicaid were more likely to be African American or of another minority race, female, and to live in a low-income area. For all patients, those with Medicaid insurance were less likely to initiate or complete chemotherapy and less likely to be evaluated by a medical oncologist. Older patients in general were also less likely to initiate chemotherapy, even though studies have shown that these patients benefit from adjuvant treatment.

"The main finding of this study is that Medicaid insurance is associated with a low likelihood of chemotherapy initiation and completion," concluded the authors. "As long as these substantially large groups of patients…have disparate treatment uptake and compliance, the nation as a whole will have difficulty reaching its goals for reduced cancer mortality."