Investigating the link between diet and prostate cancer within the ProtecT trial
Session type: Poster sessions
1University of Bristol, UK, 2Cambridge University Addenbrookes Hospital, UK, 3University of Oxford, UK, 4University of York, UK
Prostate cancer is a significant public health problem with 30,000 new cases and 10,000 deaths (14% male cancer deaths) in the UK in 2004. Although the link between diet and cancer is frequently reported, there is currently no strong evidence to support a direct link between diet and prostate health.
The ProtecT study is a UK multi-centre RCT of the effectiveness, cost-effectiveness and acceptability of treatments for clinically localised prostate cancer. The study recruited from 1999-2008 from nine centres across the UK. Unselected men aged 50-69 years were invited to have a PSA test and enter the study. On recruitment from 2004 the participants were given both a widely used Food Frequency Questionnaire (FFQ) and the more detailed Dietary Diary to complete. The dietary diary consisted of a 7-day unweighed dietary record with photographs of various portion sizes to aid description and coding. The DINER programme is used to code the diaries and the DINERMO programme to check the dietary coding.
110,380 men attended the recruitment clinics (49% of those invited by letter) and 10,297 have a raised PSA test (11.0%). There are 3,174 men diagnosed with prostate cancer (31% of those with a raised PSA), of whom 2,677 have clinically localised disease (82% of all cases). 64,187 diaries and FFQs were given out. 37,189 diaries have been returned (58% response rate). 2361 of these diaries have been coded to date on a case control basis. 41,964 FFQs have been returned (65% response rate). 13,000 FFQs have been coded on a case control basis. It is notable that the more intensive dietary diary has a lower response rate.
The cause of prostate cancer and possible impact of diet is currently unknown. A study of this size using detailed 7-day dietary records completed prior to symptoms and diagnosis will provide a unique opportunity to gain insight into the aetiology of prostate cancer. Analysis of the data is planned for 2009 2010.
The ProtecT diet study is funded by WCRF and MRC Centre for Nutritional Epidemiology in Cancer Prevention and Survival