Obesity in relation to prostate cancer risk: comparison with a population having benign prostatic hyperplasia.

OBJECTIVE: To analyse the relationship between obesity and prostate cancer, when compared with men with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: The records were reviewed of consecutive patients with histologically confirmed prostate cancer admitted for prostate surgery between January 1993 and February 1999. Controls were selected from patients who were hospitalized at the same time for the surgical treatment of BPH. One control was matched to each case by age. Obesity was defined as a body mass index (BMI) of> 29 kg/m2.
RESULTS: The study included 194 cases and 194 controls; their median (range) age at operation was 69.5 (50-88) years in both groups, and the BMI 26.1 (16.6-38.1) kg/m2 in the cancer and 25.7 (15.1-36.8) kg/m2 in the BPH group. The difference between the groups was not significant (P = 0.06). Obesity was significantly associated with prostate cancer, with an odds ratio (95% confidence interval) of 2.47 (1.41-4.34). Cases with advanced disease had a higher BMI than those with localized disease, but when age was considered the difference was not significant.
CONCLUSION: In general the BMI was not significantly associated with prostate cancer when compared with men having BPH. However, obese men had 2.5 times the risk of having prostate cancer.