Obesity has multifaceted impact on biochemical recurrence of prostate cancer: a dose–response meta-analysis of 36,927 patients

Obesity is inconsistently related to biochemical recurrence (BCR) of prostate cancer (PCa) in different epidemiological studies. We conducted a systematic review and dose–response meta-analysis of published studies from MEDLINE and EMBASE in order to determine the relationship between body mass index (BMI) and BCR of PCa. We identified a total of 26 studies including 36,927 individuals. Pooled estimates of relative risk (RR) and confidence interval (CI) were computed, and dose–response meta-analysis was subsequently performed. Based on the random-effects approach, a 5 kg/m² increase in BMI was associated with 16 % (RR 1.16, 95 % CI 1.08–1.24) higher risk of BCR for entire set of 26 studies. Significantly higher rates of BCR were also observed in radical prostatectomy series (RR 1.17, 95 % CI 1.07–1.28) and external beam radiation therapy series (RR 1.19, 95 % CI 1.10–1.28), while no significant correlation was observed in brachytherapy series (RR 0.91, 95 % CI 0.64–1.28). Different BCR outcomes came out for studies held in USA (RR 1.18, 95 % CI 1.10–1.28), Europe (RR 1.04 95 % CI 0.91–1.17) and Asia (RR 1.83 95 % CI 0.85–3.97), respectively. There was limited evidence of a nonlinear association between BMI and BCR, which showed a critical point of 33 in BMI. The findings from meta-analysis showed that excess BMI was positively correlated with BCR of PCa multifacetedly, indicating good weight control and detailed attention to treating obese patients might improve the prognosis of PCa.