Overutilization of Bilateral Mastectomies and Underutilization in Endocrine Therapy in Ductal Carcinoma in Situ in Young Women: Any Benefit to Survival?

Abstract

Multiple local treatment modalities are considered appropriate for women with DCIS and the use of hormone therapy (HT) as treatment or chemoprevention varies in part as a function of local therapy. In this study, we evaluate national trends in the local and systemic management of DCIS and identify the impact of these treatments on overall survival (OS) in young women with DCIS. We identified all DCIS cases in women <50 from 2004 to 2016 in the National Cancer Database (NCDB). Descriptive statistics were calculated to characterize the study population, log-rank test used to assess for correlation between treatment modality and OS, and multivariate Cox regression model utilized to assess for impact of demographic and disease characteristics on OS. A total of 52,150 women with DCIS <50Y were identified. The most common treatment modality was breast conservation surgery (BCS; 59%) which was followed by radiation therapy (RT) in 76% of BCS patients. Bilateral mastectomy (BM) was utilized by 19%, unilateral mastectomy (UM) in 18%, and no surgery or RT in 1.0%. While BCS was the most utilized surgical technique from 2004 (65%) to 2016 (58%), BM increased in frequency during that time (11% to 27%). This trend was magnified in women <40Y, with BM surpassing BCS in 2010 (39% and 35%, respectively; Table 1) with continued trend upwards in 2016 (BM: 45%; BCS: 35%). Table 1. Surgical utilization in patients <40. BM was more likely to be utilized by Caucasian <50Y when compared to the Black, Asian and Hispanic populations (p<0.001). Similar patterns were observed with higher levels of education and income (p<0.001). With regard to OS in <50Y, multivariate analysis revealed no benefit to BM (HR: 0.96, p<0.71) or UM (HR: 0.97, p<0.72) when compared to BCS+RT. Inferior OS was seen with BCS alone (HR: 1.33, p = 0.004), Black race (HR: 1.39, p<0.001), negative estrogen receptor (ER) status (HR: 1.80, p<0.001), and tumor size ≥ 2.5 cm (HR: 1.65, p<0.001). Among the ER+/<50Y patients, rates of HT use were significantly lower in BM (11%), UM (33%), and BCS alone (28%) when compared to BCS+RT (64%, p<0.001). Among this cohort, there was inferior OS in UM (HR: 0.95, p = 0.002) as compared to BCS+RT but not for BM. The use of bilateral mastectomies is increasing in younger patients and this rise correlates with higher education and income. There is no difference in OS in these young DCIS patients with BM vs. BCS+RT. Among ER+ patients, rates of HT are lower in the BM and UM groups as compared to BCS+RT and a decrement in survival is observed in the UM group in whom the HT may be playing a protective role with regard to the contralateral breast. Further study is needed on the influence of HT in outcomes in young women with DCIS who undergo UM.Abstract 2083; Table2004200620082010201220142016Breast Conservation Surgery47%48%43%35%34%32%35%Bilateral Mastectomy19%22%31%39%41%45%45%Unilateral Mastectomy33%28%26%26%25%22%20%No surgery1.8%1.2%0.8%0.8%0.7%0.6%0.0% Open table in a new tab