Preoperative weight change and risk of adverse outcome following radical prostatectomy: Results from the Shared Equal Access Regional Cancer Hospital database

Background:We examined the relationship between weight change in the year before radical prostatectomy (RP) and biochemical recurrence (BCR) and adverse pathology.Methods:We abstracted data from 359 men undergoing RP in the SEARCH (Shared Equal Access Regional Cancer Hospital) database between 2001-2007. Logistic regression and Cox proportional hazards models were used to test the association between weight change in the year before surgery and adverse pathology and BCR, respectively.Results:In all, 152 (42%) men gained weight, 193 (54%) lost weight and 14 (4%) had the same weight. Among weight gainers, median gain was 2.4 kg and among weight losers, median loss was 2.7 kg. As a continuous variable, weight change was not associated with adverse pathology or BCR (all P>0.05). In secondary analysis, on multivariate analysis, men gaining ≥2.5 kg were at higher BCR risk (hazards ratio1.65, 95% confidence interval (CI): 1.03-2.64, P=0.04) while weight loss ≥2.5 kg was not associated with BCR (hazards ratio0.83, 95% CI: 0.54-1.29, P=0.41).Conclusions: As a continuous variable, weight change was not associated with outcome. In secondary hypothesis-generating analyses, weight gain ≥2.5 kg in the year before surgery, regardless of final body mass index, was associated with increased BCR following RP. If validated, these data suggest weight gain 2.5 kg may promote prostate cancer progression.