ASSOCIATION BETWEEN MOLECULAR SUBTYPE OF BREAST CANCER AND SKELETAL MUSCLE MASS

• Grant number: 26/08692-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2026
• End date: February 28, 2027
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Miguel Soares Conceição
• Grantee: Maria Eduarda Pupo Bonifácio
• Host Institution: Universidade São Francisco (USF). Campus Bragança Paulista. Bragança Paulista , SP, Brazil
• Associated research grant: 21/01424-5 - Effects of combined physical training in women with Breast Cancer submitted to chemotherapy, AP.JP

Abstract

Introduction: Breast cancer is the most incident type of cancer among women and presents significant biological heterogeneity, with distinct molecular subtypes regarding their clinical, prognostic, and metabolic characteristics. In parallel, changes in body composition, especially those related to the reduction of lean mass, have clinical relevance in this population due to their association with functional and prognostic outcomes. However, it remains unclear whether patients with breast cancer of different molecular subtypes present differences in body composition before the initiation of treatment. Objectives: To investigate the association between molecular subtypes of breast cancer and appendicular lean mass, assessed by dual-energy X-ray absorptiometry (DXA), in patients prior to treatment. Additionally, secondary body composition variables will be analyzed, such as total fat mass, lower limb lean mass, and body fat percentage. Methods: This is an analytical observational subanalysis with a cross-sectional design, using baseline data from women with breast cancer included in a larger ongoing project. Preliminary results: So far, 39 patients have been evaluated, and preliminary data descriptively indicate that patients with triple-negative breast cancer present numerically lower lean mass values compared to patients with other molecular subtypes. Considering the exploratory nature and the still limited sample size, it is not possible to establish robust statistical inferences, and expanding the sample is necessary to confirm these findings. It is expected that the results will contribute to expanding knowledge about the association between molecular subtypes of breast cancer and body composition, providing a basis for future clinical investigations in this area. (AU)