Factors associated with contralateral preventive mastectomy.

Introduction: Contralateral prophylactic mastectomy (CPM) is an option for women who wish to reduce their risk of breast cancer or its local recurrence. There is limited data on demographic differences among patients who choose to undergo this procedure.

Methods: The population-based Florida cancer registry, Florida's Agency for Health Care Administration data, and US census data were linked and queried for patients diagnosed with invasive breast cancer from 1996 to 2009. The main outcome variable was the rate of CPM. Primary predictors were race, ethnicity, socioeconomic status (SES), marital status and insurance status.

Results: Our population was 91.1% White and 7.5% Black; 89.1% non-Hispanic and 10.9% Hispanic. Out of 21,608 patients with a single unilateral invasive breast cancer lesion, 837 (3.9%) underwent CPM. Significantly more White than Black (3.9% vs 2.8%; P<0.001) and more Hispanic than non-Hispanic (4.5% vs 3.8%; P=0.0909) underwent CPM. Those in the highest SES category had higher rates of CPM compared to the lowest SES category (5.3% vs 2.9%; P<0.001). In multivariate analyses, Blacks compared to Whites (OR =0.59, 95% CI =0.42-0.83, P=0.002) and uninsured patients compared to privately insured (OR =0.60, 95% CI =0.36-0.98, P=0.043) had significantly less CPM.

Conclusion: CPM rates were significantly different among patients of different race, socio-economic class, and insurance coverage. This observation is not accounted for by population distribution, incidence or disease stage. More in-depth study of the causes of these disparities in health care choice and delivery is critically needed.