Problems with recruitment

Prostate cancer is a major public health problem and there is a strong need of new preventive strategies based on drug and lifestyle interventions. It is now well-established that healthy eating patterns and increasing physical activity can prevent or delay prostate cancer progression. Intake of cruciferous vegetables (e.g. broccoli, cabbage, cauliflower, Brussels sprouts, kale) has been associated with decreased risk of prostate cancer progression; however the underlying biological mechanisms remain unknown. The investigators propose to undertake a pilot study on a group of men with early prostate cancer on active surveillance to determine whether a diet rich in broccoli will induce changes in tumor size and blood flow measured by conventional Magnetic Resonance Imaging (MRI) techniques. Men with early prostate cancer on active surveillance who have visible cancer lesions on MRI will be recruited onto this double-blinded randomized intervention and they will be asked to eat one portion of broccoli soup per week for 6 months. The investigators will test two varieties of broccoli (standard and 'Beneforte extra' broccoli) that are able to deliver two different levels of sulforaphane (SF), an active compound extensively studied for its potential anticancer properties. This study will involve MRI scans, blood and urine collection before and after a 6 month intervention period. This study design will not only allow us to observe diet-induced changes within the prostate but also at the systemic level. In addition, participant's lifestyle (habitual diet and physical activity) will be assessed by food diaries and exercise questionnaires.

This study has been funded by Biotechnology and Biological Sciences Research Council (BBSRC) and Prostate Cancer foundation (PCF).

The study is a randomised double-blinded dietary intervention study. The study population will consist of men (n=20) aged 18-80 years with a BMI between 19.5 and 35 kg/m2 with low risk prostate cancer (prostate specific antigen [PSA] < 10ng/ml; Gleason grade 6; T category T1 or T2) or intermediate risk prostate cancer patients (PSA 10-20ng/ml; Gleason 7 (including selected 4+3 cases that will not be advised for radical prostatectomy; T category T1 or T2) who have visible lesions on MRI and have already decided to take up active surveillance/monitoring. The investigators chose these inclusion criteria because they reflect the population of men on active surveillance that the investigators are currently recruiting in the ESCAPE study (Effect of Sulforaphane on Prostate CAncer PrEvention; ClinicalTrials.gov Identifier: NCT01950143) via the Norfolk and Norwich University Hospital. Volunteers recruited onto this study will be randomly allocated to one of two arms in which they will be required to consume one portion of broccoli soup per week, delivering different levels of glucoraphanin (SF precursor) in each study arm. This will be part of their normal diet for 6 months. The two soups will contain standard broccoli (i), or glucoraphanin-enriched broccoli named for the study 'Beneforte extra' (ii). The study will involve MRI monitoring at baseline and after 6 months. In addition the investigators will collect blood and urine samples at baseline and after 6 months. The volunteers' habitual diet and physical activity will also be assessed during the intervention period.

Inclusion Criteria:

• Suitable for and have chosen AS as management for localised prostate cancer
• MRI visible detected lesion ≥0.5 cm in the axial plane, corresponding to the biopsy confirmed region of prostate cancer
• No contraindication to MR scanning
• Aged 18-80 years
• BMI between 19.5 and 35 kg/m2
• Smokers and non-smokers

Exclusion Criteria:

• 5α-reductase inhibitors or testosterone replacement medicines
• warfarin
• surgically implanted pelvic metalwork
• pacemakers or other implanted electronic devices not compatible with MRI
• contra-indications to gadolinium-based contrast agents (including patients with abnormal renal function)
• Glomerular Filtration Rate (GFR) <60 ml/min
• claustrophobia
• allergies to any of the ingredients of the broccoli soups
• dietary supplements or herbal remedies which may affect the study outcome - unless the volunteer is willing to discontinue taking them for 1 month prior to starting study
• parallel participation in another research project that involves dietary intervention