Abstract PO5-11-10: Quality of life in Brazilian women with early breast cancer on adjuvant endocrine therapy

Abstract Background: There is a significant scarcity of quality of life (QOL) data among the Brazilian population with breast cancer. This study aims to evaluate QOL in Brazilian women with early breast cancer treated with adjuvant endocrine therapy (ET) and to explore its relationships with patients’ clinical and social characteristics, type and duration of endocrine therapy and type of healthcare insurance. Methodology: Women with a history of early-stage estrogen-receptor positive invasive carcinoma of the breast on adjuvant endocrine therapy for at least 6 months were invited to participate of this study. QOL assessment was conducted using the EORTC QLQ-C30 and EORTC QLQ-BR23 questionnaires. Demographic and medical information were collected from medical records. Data collection performed using RedCap software. Qualitative variables were compared between groups using the Chi-square or exact Chi-square test and for quantitative variables the non-parametric Mann-Whitney test was used. Multivariable analysis was performed using Multiple linear regression models with Stepwise procedure. P 0.05 was considered significant. Analyzes were performed in SAS 9.4. Results: From June 2021 to May 2023, a total of 461 women with ER+ early-stage breast cancer from 12 Brazilian institutions were included in this analysis. A total of 233 women (50.54%) were treated in private institutions. Mean age was 56.02 years (range 22-93), 47.69% were non-white and 38.7% were premenopausal. A total of 62.34% had prior lumpectomy, 43.1% had tumor stage II, 61.69% received prior chemotherapy and 15.18% were HER2 positive. Regarding ET, 45.2% were on aromatase inhibitors (AI), 40.61% on tamoxifen (TMX) and 14.19% on ovarian function suppression plus ET (OFS). Median duration of ET use was 2.78 years. From the adjustment of the multiple regression model, it was found that the variable patients with a higher educational level were a significant predictor for the Physical Functioning score (p 0.0001). The Role Functioning score had the variables treatment in a private hospital (p = 0.0462) and a higher educational level (p = 0.0357) as significant predictors. The variables age 60 years (p = 0.0006) and marital status: single (p = 0.0267) were significant predictors for the Emotional Functioning score. Cognitive Functioning was correlated with the variables age 60 years (p 0.0001) and treatment duration 2 years (p = 0.0475). Social Functioning had significant predictors such as hormone therapy with AI (p = 0.0305) and hormone therapy with TMX (p = 0.0267) when compared to OFS, as well as treatment duration 2 years (p = 0.0175). The variable age 60 years was a predictor for the Fatigue score (p = 0.0233). The Pain score correlated with variables such as higher educational level (p = 0.0003) and treatment duration 2 years (p = 0.0032). The variables treatment in a public hospital (p = 0.0066), age 60 years (p = 0.0471), and treatment duration 2 years (p = 0.0054) were predictors for a higher Arm Symptoms score. Regarding the Breast Symptoms score, the variables treatment in a public hospital (p = 0.0005), Caucasian ethnicity (p = 0.0006), radiation therapy (p = 0.0098), and treatment duration 2 years (p = 0.0203) were predictors for the total score. Body Image correlated with variables such as age 60 years (p = 0.0322), surgical approach: mastectomy (p = 0.0445), tumor size 50mm (p = 0.0446), and radiation therapy (p = 0.0405). The Global health status score did not correlate with any variable. Conclusion: Lower educational level, age 60 years, duration of ET less than 2 years had a significant impact in many domains of QOL. Radiotherapy was the treatment modality with more impact in QOL scores. The identification of modifiable factors related to QOL in this study provides valuable insights for the development of a customized intervention in Brazilian population. Citation Format: Danielle Santos, Cristiano Souza, Maria Cristina Magalhães, Daniela Pereira, Fernanda Moura, Sulene Oliveira, Anna Luiza Galvão, Bruno Souza, Amanda Castro, Monalisa Andrade, Andrea Shimada, Yuri Beckedorff, Carlos Paiva, Heloísa Resende, Angelica Rodrigues, Daniela Rosa, Daniele Assad-Suzuki, Romualdo Barroso-Sousa. Quality of life in Brazilian women with early breast cancer on adjuvant endocrine therapy 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 PO5-11-10.