E67: Disparities, Time to Surgery, and Survival in Contralateral Prophylactic Mastectomy: A Review of the National Cancer Database

Contralateral prophylactic mastectomy (CPM) rates have continued to increase despite no clear survival benefit and controversy surrounding potential overtreatment as well disparities regarding which patients receive CPM. The aims of this study were to determine differences in demographic and socioeconomic factors between patients who did and did not undergo CPM and to evaluate differences in overall survival and time to surgery between these two groups.

Methods:

We conducted a retrospective review of the National Cancer Database of women ≥18 years old diagnosed with Stage 0-III, non-inflammatory breast cancer in 2010-2019 who underwent mastectomy with or without CPM. Age, race/ethnicity, insurance status, geographic region, median household income, Charlson-Deyo Comorbidity Score, stage, receipt of reconstruction, and time to surgery were collected for each patient. A multivariate logistic regression was utilized to estimate the association between patient demographics and receiving CPM, after adjustment for known covariates. Cox Proportional Hazard Regression analyses were utilized to assess the association between OS and time to surgery (TTS).

Results:

This cohort included 1,282,151 patients. 9.5% underwent CPM. Of CPM patients, 43% had cT2-3 and 4.1% cN2-3 disease, vs 29% and 2.1% for mastectomy alone. Black patients (OR 0.79, CI 0.77 - 0.80, p < 0.05) and Asian patients (OR 0.77, CI 0.74 - 0.79, p < 0.05) had significantly lower odds of receiving CPM compared to white patients. Patients with low area-level annual income (i.e., less than $40k, OR 0.88, CI 0.86 - 0.91), who were uninsured (OR 0.67, CI 0.63 - 0.71), or had a higher Charlson-Deyo Index Score (OR 0.79, CI 0.71 - 0.87) all had significantly lower odds of receiving CPM (all p< 0.05). Patients who did not receive CPM or reconstruction had a mean of 58 days from diagnosis to surgery, compared to those who had CPM and reconstruction with 87 days to surgery. Among patients who did receive CPM, those whose TTS was within 31-60 days (HR of 0.75 (CI 0.71-0.79, p < 0.001) and 61-90 days (HR of 0.80 (CI 0.74-0.86, p < 0.001) of diagnosis had improved survival vs those who underwent surgery within 30 days; there was no significant difference in survival between CPM recipients who underwent surgery within 30 days vs 91+ days after diagnosis (Table).
 

Conclusions:

Our findings confirm persistent demographic differences in CPM receipt but provide reassurance that delays of up to and even slightly beyond 90 days may not be associated with worse survival despite these patients having more advanced disease.