PP391 - FROM PRECLINICAL TO CLINICAL OBESITY: PROGRESSIVE DECLINE IN CELLULAR INTEGRITY AND FAT-FREE MASS IN BREAST CANCER

PP391

FROM PRECLINICAL TO CLINICAL OBESITY: PROGRESSIVE DECLINE IN CELLULAR INTEGRITY AND FAT-FREE MASS IN BREAST CANCER

G. A. Barbosa¹, O. S. Queiroz¹, N. R. Damasceno², M. D. R. Sousa², D. C. Gonçalves³, F. T. Vieira^4,*, S. M. M. L. Verde¹

¹Graduate Program in Nutrition and Health, State University of Ceara, Fortaleza, ²Nutrition, University of São Paulo, São Paulo, ³Graduate Program in Nutrition , Federal University of São Paulo, Santos, Brazil, ⁴Department of Agricultural, Food and Nutritional Science, , University of Alberta, Edmonton, Canada

Rationale: Obesity is associated with poorer prognosis in breast cancer (BC), affecting body composition and cellular integrity, but stage-related differences remain unclear. This study examines the link between obesity progression and changes in cellular integrity and muscle-related compartment.

Methods: Cross-sectional study with 456 females with BC. Obesity was classified as preclinical (PCO: BMI ≥25kg/m² and waist circumference≥88 cm) and clinical (CO: PCO plus metabolic dysfunction). Body composition (fat-free mass [%FFM]) and cellular integrity (phase angle [PA], and reactance [Xc]) were assessed by bioelectrical impedance. Group comparisons (non-obesity [NO], PCO, and CO) used ANOVA with Tukey post hoc, and associations were tested by linear regression.

Results: Mean age was 50.4 ± 10.6 years; most were non-white (84.6%), had luminal tumors (78.9%), and were postmenopausal (50.6%). No group differences were found for PA (p=0.071). Xc decreased progressively across groups (ohms;NO:69.0±13.2; PCO:61.1±10.4; CO:56.1±11.8; p<0.001) with significant differences across all groups (post hoc). %FFM was lower in the PCO and CO compared to the NO (NO: 67.6±8.9; PCO: 62.8±6.8; CO:60.3±7.8; p=0.011). In regression, obesity (PCO and CO) was associated with a reduction of 9.4 ohms in Xc (R²=0.090; 95%CI:-12.11 to -6.62; p<0.001) and 5.6 percentage points in %FFM (R²=0.075;95%CI:-7.40 to -3.78; p<0.001) compared to the NO. CO showed an additional reduction compared to PCO, with a 4.9-ohm decrease in Xc (R²=0.042;95%CI:-7.37 to -2.54;p<0.001) and a 2.5 point decrease in %FFM (R²=0.024; 95%CI:-4.05 to -0.86;p=0.003).

Conclusion: Progression from PCO to CO was associated with lower Xc and %FFM, suggesting impaired cellular integrity and reduced muscle-related compartment. These findings underscore the importance of comprehensive body composition monitoring in females with BC across obesity stages.

Disclosure of Interest: None declared