Abstract Background Adiposity has been characterised as a modifiable risk factor of prostate cancer. Its association with outcomes after prostate cancer diagnosis, however, needs to be better understood and obtain more evidence to assist the development of lifestyle guidance for prostate cancer patients. Methods We investigated the associations between adiposity indices close to prostate cancer diagnosis (up to two years pre- or up to five years post-diagnosis) and mortality in 1,968 men of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Men were followed for a median of 9.5 years. Cox proportional-hazards models were adjusted for age and year of diagnosis, stage, grade, smoking and stratified by country. Results Each 5-unit increment in pre- or post-diagnosis body mass index (BMI) combined was associated with a 30% higher rate of all-cause and a 49% higher rate of prostate cancer-specific mortality. Similarly, each 5-unit increment in pre-diagnosis BMI was associated with a 35% higher rate of all-cause and a 51% higher rate of prostate cancer-specific mortality. The associations were less strong for post-diagnosis BMI with a lower number of men in analyses. Less clear positive associations were shown for waist circumference, hip circumference, and waist-to-hip ratio but data was limited. Conclusions Elevated levels of adiposity close to prostate cancer diagnosis could lead to higher risk of mortality; therefore, men are encouraged to maintain a healthy weight. Additional research is needed to confirm if excessive adiposity after prostate cancer diagnosis could worsen prognosis.

Adiposity assessed close to diagnosis and prostate cancer prognosis in the EPIC study