Breast Cancer Stage and Treatment Among Ohio Medicaid Beneficiaries With and Without Mental Illness

Purpose: There is a dearth of studies on cancer outcomes in individuals with mental illness. We compared breast cancer outcomes in Medicaid beneficiaries with and without mental illness. Methods: Using records from the 1996 to 2005 Ohio Cancer Incidence Surveillance System (OCISS) and Medicaid files, we identified fee-for-service women age < 65 years diagnosed with incident invasive breast cancer who had enrolled in Medicaid >= 3 months before cancer diagnosis (n = 2,177). We retrieved cancer stage, patient demographics, and county of residence from the OCISS. From Medicaid claims data, we identified breast cancer treatment based on procedure codes and mental illness status based on diagnosis codes, prescription drugs dispensed, and service codes. We developed logistic regression models to examine the association between mental illness, cancer stage, and treatment for locoregional disease, adjusting for potential confounders. Results: Women with mental illness represented 60.2% of the study population. Adjusting for potential confounders, women with mental illness were less likely than those without mental illness to have unstaged or unknown-stage cancer (adjusted odds ratio [OR], 0.61; 95% CI, 0.44 to 0.86; P = .005) or to be diagnosed with distant-stage cancer (adjusted OR, 0.59; 95% CI, 0.40 to 0.85; P = .005). We observed no difference by mental illness status in receipt of definitive treatment (adjusted OR, 1.04; 95% CI, 0.84 to 1.29; P = .08). Conclusion: Among Ohio Medicaid beneficiaries, women with mental illness did not experience disparities in breast cancer stage or treatment of locoregional disease. These findings may reflect the equalizing effects of Medicaid through vulnerable individuals' improved access to both physical and mental health care.