Introduction

Obesity might negatively affect prostate cancer (PCa) outcomes. However, evidence according to the associations between obesity and metastases-free, as well as PCa-specific survival after radical prostatectomy (RP) is still inconsistent.

Methods

We relied on PCa patients treated with RP at the Martini-Klinik Prostate Cancer Center between 2004 and 2015. First, multivariable Cox-regression analyses examined the impact of obesity on metastases, PCa-specific death, and death of any cause after RP. Last, in a propensity score matched cohort, Kaplan-Meier analyses assessed metastases-free and overall survival according to body mass index (kg/m2) (BMI) strata (?30 vs. <25).

Results

Of 13,667 individuals, 1,990 (14.6%) men were obese (BMI ?30). Median follow-up was 36.4 month (IQR: 13.3-60.8). Obese patients were less likely to exhibit metastases after RP (HR: 0.7, 95% CI: 0.5-0.97, p=0.03, table 1). Similarly, after propensity score adjustment obesity was associated with increased metastases-free survival (log rank p=0.001). Obesity was not significantly associated with PCa-specific death (HR: 1.2; 95% CI: 0.5-2.7; p=0.8), but with higher risk of death of any cause after RP (HR: 1.7; 95% CI: 1.3-2.3; p=0.001). Similarly, after propensity score adjustment obesity was associated with decreased overall survival after RP (log rank p=0.001).

Conclusions

Obesity was associated with decreased risk of metastases after RP. Improved medical care of diabetes might have contributed to the latter observation. However, further research is needed to unravel the controversially debated association between obesity and PCa.

Funding

None