Surgical Management of Breast Cancer: Patterns, Trends, and Economic Burden of Women in a Privately Insured Population in Texa

Objective: The overall objective of this study is to understand the patient, provider, and area-level factors associated with utilization patterns of surgery for unilateral breast cancer. Furthermore, the study examines the geographic variation in and medical costs associated with surgical treatment for breast cancer among women with unilateral breast cancer in a privately insured population in Texas. Method: We used a retrospective population-based cohort study design with enrollment and administrative claims data for women ages 18 years and older, insured by Blue Cross Blue Shield of Texas from 2008 to 2013. The study cohort consisted of women with a unilateral breast cancer diagnosis and a claim for breast surgery (breast conserving surgery (BCS) or mastectomy). Clinical and economic outcomes included: (1) type of breast surgery received and (2) one-year total medical and reconstruction-related costs; the main predictor variable was the receipt of genetic testing for genetic susceptibility to breast cancer. Generalized linear mixed models were used to determine the factors associated with the type of breast surgery received. Generalized linear models were used to predict the one-year costs of surgical treatment with and without reconstructive surgery. Results: A total of 1,771 women were included in the study cohort (927 = BCS, 844 = mastectomy). 42.4% of women had a claim for genetic testing and 32.7% of women had a reconstructive procedure within one year following index breast surgery. Patient-level factors were found to be significantly associated with surgical treatment for breast cancer. Receipt of genetic testing, as well as patient comorbidity had a significant impact, such that sicker patients were more likely to have received BCS rather than mastectomy. Provider and area-level characteristics were not significant predictors of the type of surgery received. Rates per 100,000 for both surgery groups decreased across the study period, with the exception of an unexplained spike in 2009. Significant geographic variation was found to exist across the state. A much higher percentage of women in the mastectomy group had a reconstructive procedure (90% vs 10%, p<0.0001). Results from the generalized linear model showed that patients who received BCS had significantly lower adjusted total medical costs ($173,372 vs $232,582, p<0.001), lower adjusted reconstruction-related costs ($39,392 vs $89,590, p<0.001), and lower inpatient costs ($99,907 vs $139,832, p<0.001). Conclusions: This study shows the significant impact of genetic testing on the type of breast cancer surgery received following the first national recommendations on the issue. As hypothesized, women who did not have genetic testing for breast cancer were less likely to undergo mastectomy.