Demographic and Socioeconomic Risk Factors for Granulomatous Mastitis in the United States: A Case-Control Study

Granulomatous mastitis (GM) is a benign breast disease that can have an extended clinical course impacting quality of life and causing breast disfigurement. Granulomatous mastitis has been studied throughout the world; however, less is known about GM patients in the United States. We aim to identify demographic and socioeconomic factors associated with GM in the United States.

An IRB-approved retrospective case-control study was performed of 92 patients with biopsy-proven GM at two institutions in Los Angeles, California: a safety-net hospital and an academic institution. Age-matched controls were selected from patients presenting for diagnostic breast imaging. Demographic and socioeconomic characteristics were collected. Data were analyzed using univariable test for odds ratios (ORs) with 95% confidence intervals (CIs) and multivariable conditional logistic regression.

Patients with GM were more likely to prefer Spanish language (OR 6.20, 95% CI: 2.71%-14.18%), identify as Hispanic/Latina (OR 5.18, 95% CI: 2.38%-11.30%), and be born in Mexico (OR 3.85, 95% CI: 1.23%-12.02%). Cases were more likely to have no primary care provider (OR 3.76, 95% CI: 1.97%-7.14%) and use California Medicaid for undocumented adults (OR 3.65, 95% CI: 1.89%-7.08%). In the multivariable analysis, participants who preferred Spanish language had four times higher odds of GM versus those who preferred English language (OR 4.32, 95% CI: 1.38%-13.54%).

Patients with GM may have barriers to health care access, such as preferring Spanish language, being an undocumented immigrant, and not having a primary care provider. Given these health care disparities, further research is needed to identify risk factors, etiologies, and treatments for this subset of GM patients.