[Impact of obesity on PSA in prostate cancer screening].

Objective: Obesity is associated with changes of serum levels of androgens and oestrogens which could modulate prostate metabolism. The objective of this study was to investigate a possible correlation between the PSA level and the degree of obesity in a candidate population for prostate cancer screening in order to determine whether the PSA level needs to be adapted before performing biopsy.

Material: During a screening campaign in a French district, serum PSA results and body mass index (BMI) were available for 541 men. These men were divided into 4 groups of corpulence: Normal (BMI < 25), Overweight (25 < or = BMI < 30), Stage I obesity (30 < or = BMI < 35), Stage II + III obesity (BMI > or = 35). The PSA levels of these various groups were compared, and a correlation between BMI and PSA was investigated.

Results: The mean PSA in each group was inversely proportional to BMI, with mean PSA levels of 3.7, 2.9, 2.6 and 1.5 for Normal, Overweight, Obesity I and Obesity II + III groups, respectively. A significant difference was observed between these groups (p = 0.03) and an inverse correlation was also observed between BMI and PSA (r = 0.1, p = 0.01).

Conclusion: In a population submitted to prostate cancer screening, PSA is lower as BMI increases. An adaptation of the PSA screening cutoff value according to BMI should be investigated.