Family history of prostate cancer and obesity in relation to high-grade disease and extraprostatic extension in young men with prostate cancer

BACKGROUND: Little is known about predictors of prostate cancer severity in young men. Therefore, we examined whether family history and obesity influence risk of high-grade disease and extraprostatic extension in men < 55-years old. METHODS: Four hundred ninety-eight men aged < 55 years who had had a radical prostatectomy (1992-1999) by one surgeon were mailed a survey in 2000 to assess family history of PCa and anthropometrics. Body mass index (BMI = kg/m(2)) was calculated as an indicator of obesity. Logistic regression was used to compute odds ratios (OR) for high-grade disease (Gleason score > or = 7) and extraprostatic extension. RESULTS: Of the 363 respondents, 35.8% had at least one first-degree relative with PCa. Men with a family history were younger at surgery than those without a family history (48.8 vs. 50.1 years, P < 0.001). After controlling for age, cigarette smoking, and race/ethnicity, men with an affected father had a lower risk of high-grade disease compared to those without an affected father (OR = 0.42, 95% CI 0.23-0.76). Risk of high-grade disease increased with increasing BMI, especially in men < 50-years old (P-trend = 0.02). Family history and BMI were not clearly associated with extraprostatic extension. CONCLUSIONS: After taking into account a younger age at presentation among men with a family history, young men with a family history of PCa were less likely to have high-grade disease. Obesity may be associated with a poorer histology in young men with PCa, especially in men younger than 50 years of age.