A natural history of weight change in men with prostate cancer on androgen‐deprivation therapy (ADT): results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database

Study Type – Harm (cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? Prior studies have shown that men undergoing ADT tend to gain weight, with a net increase in fat mass and decrease in bone density and lean body mass. We sought to characterize the natural history of weight gain on ADT by studying patients over a three‐year interval, finding that most weight gain occurs within the first year of initiating therapy. Furthermore, we confirm these prior findings in a more racially heterogeneous population of men, an important finding given the different outcomes of prostate cancer in black and white men. OBJECTIVES To better understand the natural history of weight change with androgen‐deprivation therapy (ADT), we investigated the effect of ADT on body weight among men from the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Men undergoing ADT lose lean muscle but gain fat mass, contributing to an overall gain in weight. PATIENTS AND METHODS We identified 132 men in SEARCH who received ADT after radical prostatectomy. ‘Weight change’ was defined as the difference in weight before starting ADT (6 months before ADT) and the on‐ADT weight (between 6 and 18 months after starting ADT). In a subanalysis, baseline characteristics of weight‐gainers and ‐losers were analysed using univariate and multivariate analysis to test association with weight change. RESULTS In all, 92 men (70%) gained weight, and 40 (30%) either lost or maintained a stable weight. On average, weight on ADT was 2.2 kg higher than the weight before ADT, with the mean change for weight‐gainers and ‐losers being +4.2 kg and −2.4 kg, respectively. This compared with no significant weight change in the year before starting ADT (paired t ‐test, change −0.7 kg, P = 0.19) or in the second year on ADT (paired t ‐test, change −0.5 kg, P = 0.46) for 84 men in whom these additional weight values were recorded. There was no significant association between any of the features examined and weight change on univariate and multivariate analysis. CONCLUSION In this longitudinal study, ADT was accompanied by significant weight gain (+2.2 kg). This change occurred primarily in the first year of therapy, with men neither losing nor gaining additional weight thereafter.