Evaluation of overall survival and barriers to surgery for patients with breast cancer treated without surgery: a National Cancer Database analysis

Surgery remains the foundation of curative therapy for non-metastatic breast cancer, but many patients do not undergo surgery. Evidence is limited regarding this population. We sought to assess factors associated with lack of surgery and overall survival {OS) in patients not receiving breast cancer surgery. Retrospective cohort study of patients in the US National Cancer Database treated in 2004-2016. The dataset comprised 2,696,734 patients; excluding patients with unknown surgical status or stage IV, cTO, cTx, or p15, metastatic or recurrent disease resulted in 1,192,294 patients for analysis. Chi-square and Wilcoxon rank-sum tests were used to assess differences between groups. OS was analyzed using the Kaplan-Meier method with a Cox proportional hazards model performed to assess associated factors. In total 50,626 (4.3%) did not undergo surgery. Black race, age >50 years, lower income, uninsured or public insurance, and lower education were more prevalent in the non-surgical cohort; 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 the non-surgical patients 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 (no-chemo) months) and RT (85 vs 56 (noRT) 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 triple negative ER+ (HR 0.66, 95% CI 0.59-0.75, P < 0.001) and HER2(+) (HR 0.74, 95% CI 0.65-0.84, P < 0.001) subgroups while RT improved OS for ER + (HR 0.72, 95% CI 0.64-0.82, P < 0.001) and favorable-disease (ER+, early-stage, age >60) (HR 0.61, 95% CI 0.45-0.83, P = 0.002) subgroups. Approximately 4% of women with breast cancer do not undergo surgery, particularly those with more aggressive disease and lower socioeconomic status. Despite its benefits, RT was underutilized. This study provides a benchmark of survival outcomes for patients who do not undergo surgery and highlights a potential role for use of RT.

Automated summary

Surgery remains the mainstay of curative therapy for non-metastatic breast cancer, but a small percentage of patients do not undergo surgery. Factors associated with lack of surgery include black race, older age, lower income, and lack of insurance or public insurance. Patients who did not undergo surgery had higher disease stage and more aggressive disease biology, with only a small portion receiving radiation therapy. Age, race, income, insurance status, disease stage, tumor subtype, treatment facility type and location, and receipt of radiation therapy were associated with overall survival in non-surgical breast cancer patients. Subgroup analysis showed that chemotherapy improved survival in certain subgroups, while radiation therapy was beneficial for others. This study highlights the importance of considering alternative therapies for patients who do not undergo surgery for breast cancer.