Association between body mass index and localized prostate cancer management and disease-specific quality of life

Purpose: The purpose of this work is to describe the association between body mass index (BMI) and (1) management option for localized prostate cancer (PCa) and (2) disease-specific quality of life (ds-QoL) after treatment or active surveillance. Subjects/patients and methods: We analysed data from men with localized PCa managed with radical prostatectomy (RP), radiation therapy (RT), or active surveillance (AS) in a prospective, population-based cohort study. We evaluated the association between BMI and management option with multivariable multinomial logistic regression analysis. The association between BMI and ds-QoL was assessed using multivariable longitudinal linear regression. Regression models were adjusted for baseline domain scores, demographics, and clinicopathologic characteristics. Results: A total of 2378 men were included (medians [quartiles]: age 64 [59–69] years; BMI 27 kg/m²; 77% were non-Hispanic white); 29% were obese (BMI ≥ 30). Accounting for demographic and clinicopathologic features, BMI ≥ 28 kg/m² was inversely associated with the likelihood of receiving RP (compared with RT) and became statistically significant at BMI ≥ 33 kg/m² (maximum adjusted relative risk ratio = 0.80, 95% CI 0.67 to 0.95, p = 0.013 for BMI ≥ 33 vs. 25). Conversely, BMI was not significantly associated with the likelihood of receiving AS compared with RT. After stratification by management option, obese men who underwent definitive treatment were not found to have clinically worse ds-QoL. Obese men initially on AS appeared to have worse urinary incontinence than nonobese men, but this was not significant on an as-treated sensitivity analysis. Conclusions: Among men with localized PCa, those with BMI ≥ 33 kg/m² were less likely to receive surgery than radiation. Obesity was not associated with ds-QoL in men undergoing definitive treatment, nor in men who remained on AS.