Disparities in Breast-Conserving Therapy vs. Mastectomy among Asian American and Pacific Islander Women

Abstract

Multiple randomized trials support the use of breast-conserving therapy (BCT), defined as lumpectomy followed by adjuvant radiotherapy, as an alternative to mastectomy for definitive treatment of early-stage (T1-2N0) breast cancer. However, data suggest that Asian American, Native Hawaiian, and Pacific Islander (AANHPI) may undergo mastectomy at higher rates than BCT and may experience barriers to receipt of BCT. The purpose of this study was to examine BCT utilization by disaggregated AANHPI groups to identify differences in receipt of mastectomy versus BCT. The 2004-2017 National Cancer Database was queried to identify women age ≥18 years old diagnosed with cT1-2N0M0 breast cancer treated with either BCT or mastectomy without post-mastectomy radiation therapy. Women were classified based on self-reported race. Multivariable logistic regression defined adjusted odds ratios (OR) assessing the association between race and receipt of BCT versus mastectomy for all patients and separately by cT1-2 stage. All models were adjusted for relevant sociodemographic and clinical factors. Of 794,403 women with cT1-2N0M0 breast cancer, 239,801 (30%) received mastectomy and 554,602 (70%) received BCT. After adjusting for clinical and sociodemographic factors, AANHPI women had greater odds of receiving mastectomy over BCT, compared to White women (OR [95% CI], 1.35 [1.30-1.39]; p<0.001). In contrast, Black women were less likely than White women to receive mastectomy (0.86 [0.84-0.87]; p<0.001). Upon disaggregation, Chinese, Japanese, Filipino, Korean, Vietnamese, and Asian Indian & Pakistani women were more likely to receive mastectomy over BCT compared to White women (p<0.001 for all). Treatment at academic (1.30 [1.27-1.32]), integrated (1.24 [1.21-1.27]), and comprehensive community cancer centers (1.15 [1.13-1.17]) were all associated with greater odds of mastectomy compared to treatment at community cancer programs (all p<0.001). Greater distance from treatment facility (≥50 mi. vs. 0 to <10 mi. [reference], OR 1.50 [1.47-1.53]) and cT2 disease (1.85 [1.82-1.87]) were also associated with greater odds of receiving mastectomy (all p<0.001). In this evaluation of women with early-stage breast cancer, women from several AANHPI groups were more likely to receive mastectomy (as opposed to BCT) compared to White women. While sociocultural preferences, differences in access to and interest in reconstruction, as well as prevalent tumor-to-breast ratios may partially explain the disparities, collectively our data suggest an ongoing need for greater patient involvement in shared-decision making, particularly in vulnerable and understudied Asian populations.