Evaluation of Overall Survival and Barriers to Surgery for Breast Cancer Patients Treated Without Surgery.

Purpose/Objective(s) Surgery remains the foundation of curative therapy for non-metastatic breast cancer, but a substantial proportion of patients do not undergo surgery. Evidence is limited regarding overall survival (OS) outcomes and factors associated with lack of surgery. We sought to measure OS among patients with breast cancer who do not undergo surgery, and assess factors for association with lack of surgery and OS. Materials/Methods Retrospective cohort study of patients in the US National Cancer Data Base from 2004–2016. The dataset comprised 2,696,734 patients; excluding patients with unknown surgical status or stage IV, cT0, cTx, or pIS, metastatic or recurrent disease resulted in 1,192,294 patients for analysis. Descriptive statistics were used to summarize patient characteristics. Chi-square tests and Wilcoxon rank-sum were used to test for differences between variables between groups. OS was analyzed utilizing the Kaplan-Meier method for non-surgical patients diagnosed in 2010–2015 to account for receptor status (Median follow-up time 34 months). The Cox proportional hazards model was used to assess association of risk factors with OS. Results Of the 1,192,294 patients, 50,626 (4.3%) did not undergo surgery. Socioeconomic factors that were more prevalent in the non-surgical cohort were Black race, age > 50 years, lower income, uninsured or public insurance, and lower education; this group was also more likely to have more comorbidities, higher disease stage, and more aggressive disease biology. Only 3,689 non-surgical patients (7.3%) received radiation therapy (RT). Median OS time for all patients who did not have surgery was 58 months (3-year and 5-year OS rates 63% and 49%). Median OS times were longer for patients who received chemotherapy (80 vs 50 months) and RT (85 vs 56 months). On multivariate analysis, age, race, income, insurance status, comorbidity score, disease stage, tumor subtype treatment facility type and location, and receipt of RT were associated with OS. On subgroup analysis, receipt of chemotherapy improved OS for patients with high-risk (triple-negative, HER2+) disease, whereas receipt of RT led to improved OS for patients with ER+ and favorable (ER+, early-stage, age > 60) disease. Conclusion More than 4% of women with non-metastatic breast cancer do not undergo surgery for their cancer, particularly those with more aggressive disease, of minority race/ethnicity and lower socioeconomic status. Despite its known benefits, RT was significantly underused. This study provides one of the first benchmarks of survival outcomes for patients who do not undergo surgery for breast cancer, and highlights a potential role for increased use of RT. Additionally this report highlights significant disparities effecting women of minority race/ethnicity and lower socioeconomic status.