Abstract P4-07-32: Prognostic factors among elderly patients with operable non-metastatic breast cancer treated with primary endocrine therapy

Abstract

Abstract Background: The growing population of elderly patients with breast cancer imposes challenges for treatment when frailty and comorbidities may coexist. Age alone should not be a cutoff for cancer treatment decisions: benefit and risk should be taken into account, considering comorbidities burden, functionality, life expectancy and patient preferences. Primary endocrine therapy (PET) represents an alternative when primary surgery or neoadjuvant chemotherapy would not be adequate treatment choices for patients with hormonal receptor positive (HR+) non-metastatic breast cancer. We aimed to evaluate the prognostic factors associated with survival among elderly patients treated with PET with or without surgery. Methods: We retrospectively reviewed electronic medical records of a cohort of patients who were 70 years of age or older and were treated with PET for operable non-metastatic breast cancer in an academic cancer center from 2009 to 2021. Study endpoints were progression-free survival (PFS), overall survival (OS), and factors associated with PFS and OS. For PFS, the events considered were disease progression in patients treated with PET alone, disease recurrence in those who underwent surgery, or death from any cause. Survival was estimated using the Kaplan-Meir method and compared with the log-rank test. Prognostic factors evaluated were age, histological type, grade, Ki67 index, stage, ECOG-performance status (ECOG-PS) and comorbidities burden, according to Charlson index. Univariate and multivariable analysis were performed using Cox regression. Results: PET was the first treatment for 197 pts aged 70 years or older. The median age was 81 years (range 70-101). Most patients had ductal (N=149; 75%) or lobular carcinomas (N=22; 11%), grade 1 (N=48; 24%) or grade 2 (N=114; 58%), and stage II (N=67; 34%) or stage III (N=94; 48%) disease. Half of the patients had an ECOG-PS 3 (n=65) or 4 (n=35); 165 pts (83%) had an Charlson index < 6. Seventy-two pts (36%) underwent surgery. Thirty pts (15%) had a disease recurrence or progression and 60 pts (30.5%) died; most deaths (n=38; 63%) were not related to breast cancer. In a multivariable analysis, pts with grade 3 disease had higher risk of recurrence/progression/death (HR 3.31, 95% CI 1.45-7.58, P=0.005), while those treated with surgery had a decreased risk (HR 0.37, 95% CI 0.21-0.65; P=0.001). Median PFS was 55.2 mo for pts treated with PET alone and 99.7 mo in those treated with ET followed by surgery. Median OS was 63 mo and 111.9 mo, respectively. Conclusion: In this cohort, deaths observed were mostly unrelated to breast cancer, suggesting that PET is an appropriate choice for selected pts. Nevertheless, patients with grade 3 disease and those who were not treated with surgery after PET had a higher risk of disease progression/recurrence or death. Prognostic factors can be useful to select candidates for PET. Citation Format: Erika Andrade Rocha, Jessica Monteiro Vasconcellos, Sofia Vidaurre Mendes, Pedro José Galvão Freire, Ana Paula Messias, Leticia Vecchi Leis, Otavio Noschang Moreira, Mauricio Baptista Pereira, Bruna Zanin Orsi, Augusto Araujo Neto, Vanessa Petry, Renata Colombo Bonadio, Laura Testa. Prognostic factors among elderly patients with operable non-metastatic breast cancer treated with primary endocrine therapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-32.