Impact of Availability of Immediate Breast Reconstruction on Bilateral Mastectomy Rates for Breast Cancer across the United States: Data from the Nationwide Inpatient Sample

Background: Availability of immediate breast reconstruction (IBR) varies among institutions, yet the impact of IBR availability on the rates of bilateral mastectomy (BM) versus unilateral mastectomy (UM) for breast cancer is unknown. Methods: From the 2002 to 2010 Nationwide Inpatient Sample, we identified women with breast cancer undergoing UM or BM with and without IBR using ICD-9 codes. Hospitals were classified as performing IBR if at least one hospitalization included both mastectomy and reconstruction and then by IBR volume. Statistical comparisons utilized Chi square tests, tests for trend, and multivariable logistic regression. Results: We identified 130,420 women undergoing UM (76.9 %) or BM (23.1 %) for breast cancer. Of 6,579 hospitals, 3,358 (51.0 %) performed no IBRs, while in the remaining 3,221 hospitals, 1 to 638 IBRs were performed per year. Large, teaching, urban, and Northeastern hospitals were more likely to have higher IBR volumes. BM rates were significantly higher in patients treated at those hospitals with higher IBR volumes, from 33.1 % at hospitals performing ≥24 IBRs per year to 9.0 % at hospitals without IBR (p < 0.001). Upon adjusted analysis, patients who elected BM were more likely to be seen at hospitals performing ≥24 IBRs per year (odds ratio 1.69 vs. UM, p < 0.001). Conclusions: In this analysis of national data, BM rates were higher in hospitals where IBR was available, suggesting a significant influence of institutional factors on treatment options for breast cancer patients. Efforts are needed to ensure patients have access to IBR when desired and to better understand the reasons for hospital variation in BM rates.