Development and Comparability of a Short Food-Frequency Questionnaire to Assess Diet in Prostate Cancer Patients: The Role of Androgen Deprivation Therapy in CArdiovascular Disease - A Longitudinal Prostate Cancer Study (RADICAL PC) Substudy.

BACKGROUND:There are few concise tools to evaluate dietary habits in men with prostate cancer in Canada. OBJECTIVE:The aim was to develop a short food-frequency questionnaire (SFFQ) in a cohort of prostate cancer patients. METHODS:A total of 130 men with prostate cancer completed the SFFQ and a validated comprehensive food-frequency questionnaire (CFFQ). Both questionnaires were administered at baseline and 6 mo later. RESULTS:We found good correlation between the SFFQ and the CFFQ for seafood, dairy, egg, fruits, potatoes, grains, soft drinks, and processed meat (Spearman rank correlation >0.5). Moderate correlation was found for meat, sweets, vegetables, protein, and carbohydrates (Spearman rank correlation: 0.3-0.5). We found a weaker correlation for total fat measured by SFFQ and CFFQ (Spearman rank correlation <0.3). There was adequate reproducibility during the 6-mo follow-up among all food groups and nutrients, with the exception of meat. CONCLUSIONS:Our SFFQ can be considered an appropriate tool to be used for measuring the habitual dietary intake of prostate cancer patients. This trial was registered at www.clinicaltrials.gov as NCT03127631.