Body mass index, obesity and risk of prostate cancer: a systematic review and meta-analysis

Prostate cancer (PCa) is one of the most diagnosed cancer in male. Body mass index (BMI) has been linked to the risk of cancer and its mortality. Our objective was to undertake a quantitative analysis elucidating the relationship between BMI and the risk of PCa.

A literature search was conducted in PubMed, ProQuest, and EMBASE using relevant keywords and phrases. BMI was classified as underweight (BMI <18.5 kg/m²), normal (18.5-25 kg/m²), overweight (25-30 kg/m²), and obese (>30 kg/m²). We used random-effect model to assess relative risk (RR) of PCa incidence and mortality.

A total of 13 studies were included in quantitative analysis. Underweight patients exhibited a decreased risk of PCa compared to those with normal weight (RR: 0.44; 95% CI 0.04-5.08; p = 0.51). Higher BMI has been associated with higher risk of PCa among overweight patients (RR: 1.08; 95% CI 1.06-1.11; p <0.00001) and obese patients (RR: 1.12; 95% CI 1.07-1.17; p <0.00001) respectively. The combined analysis of overweight and obese individuals also indicated a heightened risk of PCa (RR: 1.02; 95% CI 1.04-1.11; p <0.0001). Mortality rates were higher in overweight and obese individuals, though not statistically significant (RR 1.15; 95% CI 0.88-1.52; p = 0.31).

BMI >25 kg/m² was associated with an increased risk of prostate cancer and mortality.