Efficacy of a weight loss program prior to robot assisted radical prostatectomy in overweight and obese men with prostate cancer

Background: Obesity in prostate cancer patients is associated with poor prostate-cancer specific outcomes. Exercise and nutrition can reduce fat mass; however, few studies have explored this as a combined pre-surgical intervention in clinical practice. Purpose: This study examined the efficacy of a weight loss program for altering body composition in prostate cancer patients prior to robot assisted radical prostatectomy (RARP). Methods: A retrospective analysis of 43 overweight and obese prostate cancer patients, aged 47-80 years, who completed a very low-calorie diet (similar to 3000-4000 kJ) combined with moderate-intensity exercise (90 min/day) prior to RARP. Whole body and regional fat mass (FM) and lean mass (LM) were assessed by dual-energy x-ray absorptiometry preand post-program. Body weight, waist circumference, and blood pressure were assessed weekly, with surgery-related adverse effects recorded at time of surgery and follow-up appointments. Results: With a median of 29 days (IQR: 24-35days) on the program, patients significantly (p < 0.001) reduced weight (-7.3 +/- 2.9 kg), FM (-5.0 +/- 2.6 kg), percent body fat (-3.1 +/- 2.5%), trunk FM (-3.4 +/- 1.8 kg), LM (-2.4 +/- 1.8 kg), and appendicular LM (-1.2 +/- 1.0 kg). Lower weight, FM, percent FM, trunk FM, and visceral FM were associated with less surgery-related adverse effects (r(s) = 0.335 to 0.468, p < 0.010). Systolic and diastolic blood pressure were reduced (p < 0.001) by 15 +/- 22 and 8 +/- 10 mmHg, respectively over the weight loss intervention. Conclusion: Undertaking a combined low-calorie diet and exercise program for weight loss in preparation for RARP resulted in substantial reductions in FM, with improvements in blood pressure, that may benefit surgical outcomes.