Abstract PS13-07: Systemic therapy in geriatric patients with triple negative breast cancer: a National Cancer Database analysis

Abstract Background Breast cancer (BC) incidence increases with age and is the leading cause of new cancer diagnosis among women in the United States. Although the median age of diagnosis is 63 years (yrs.), over a third of patients diagnosed, and about half of BC mortality in Western societies are in patients over 70 yrs. old. Overall, outcomes for early-stage BC have improved. Despite the lower incidence of triple negative BC (TNBC) (12%-15%) the 5-year survival is 8% to 16% lower than in hormone receptor-positive BC. With the improved life expectancy in the US and the increased incidence of BC as patients age, it is of vital importance to know how to treat BC in the elderly. Unfortunately, optimal management of BC among the elderly has not been adequately studied due to underrepresentation in clinical trials. Furthermore, there is limited information of the potential toxicity and real benefit of chemotherapy in older patients. Methods This is a retrospective analysis of data collected from the National Cancer Database (NCDB), a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society, during the years 2004 to 2019. All women ≥65yrs with early stage TNBC (stages I-III) were included in the analysis. Patients were categorized into three treatment groups – those who did not receive chemotherapy (No-CT), those who received chemotherapy (CT), and those who received chemotherapy and immunotherapy (CTIO). After adjusting for multiple variables including race, insurance, Charleson-Deyo score, stage at diagnosis, and receipt of loco-regional therapy, using the log rank P value, the age cutoff over which the survival rates were not significantly different between two treatment groups (No-CT and CT/CTIO) was identified. The main outcome of this study was all-cause mortality Results A total of 11,416 women with TNBC were included in the analysis. Of these, 4105 (36.0%) received No-CT, while 7311 (64.0%) received CT/CTIO. Log rank P values showed that above 81 years, there was no survival benefit between No-CT and CT/CTIO. A further analysis categorized patients into two groups – those between 65-80yrs and those ≥81 yrs. old. Cox proportional regression analysis showed that among patients between 65-80 yrs. all-cause mortality was significantly lower among patients in the CT/CTIO group compared to those in the No-CT group (hazard ratio [HR], 0.52; CI: 0.45-0.60). However, among patients ≥81yrs old, there was no significant difference in all-cause mortality between the treatment groups (hazard ratio [HR], 0.84; CI: 0.67-1.05). Conclusions: Among patients who were >81yrs old with early-stage TNBC, those who received treatment with CT/CTIO did not have an overall survival benefit as compared to those who received No-CT. Limitations of this study includes the small number of patients >81yr old who received chemotherapy which could explain why we were not able to identify a statistically significant benefit of CT/CTIO. Another limitation is that we were not able to assess breast cancer specific mortality. However, this analysis highlights the importance of individualizing treatment recommendations in older patients, who may not garner the same benefit of treatment as younger patients. Additional studies are required to clarify contributing factors and to help optimize the management of geriatric patients with TNBC. Table 1. Patient characteristics based on treatment. Citation Format: Yolcar Chamorro, Muni Rubens, Mukesh Roy, Naomi Dempsey, Reshma Mahtani, Manmeet Ahluwalia, Lauren Carcas, Ana Sandoval-Leon. Systemic therapy in geriatric patients with triple negative breast cancer: a National Cancer Database analysis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS13-07.