Transcriptional changes in prostate of men on active surveillance following a 12-month glucoraphanin-rich broccoli intervention – results from the ESCAPE randomized controlled trial

Traka M., Melchini A., Coode-Bate J., Al-Kadhi O., Shikha S., Defernez M., Troncoso Rey P., Kibblewhite H., O'Neill C., Bernuzzi F., Mythen L., Hughes J., Needs P., Dainty J., Savva G., Mills R., Ball R., Cooper C., Mithen R.. (2019)

AJCN

Background: Epidemiological evidence suggests that consumption of cruciferous vegetables is associated with reduced risk of prostate cancer progression largely attributed to the biological activity of glucosinolate degradation products, such as sulforaphane derived from glucoraphanin. As there are few therapeutic interventions for men on active surveillance for prostate cancer to reduce risk of cancer progression, dietary approaches are an appealing option for patients.
Objective: We evaluated whether consumption of a glucoraphanin-rich broccoli soup for one year leads to changes in gene expression in prostate tissue of men with localized prostate cancer.
Design: Forty-nine men on active surveillance completed a three arm parallel randomized double-blinded intervention study for 12-months and underwent transperineal template biopsy procedures and dietary assessment at the start and end of the study. Patients received a weekly 300 ml portion of soup made from a standard broccoli (control) or from one of two experimental broccoli genotypes with enhanced levels of glucoraphanin, delivering three and seven times that of control, respectively. Gene expression in tissues from each patient obtained before and after the dietary intervention was quantified by RNA sequencing followed by gene set enrichment analyses.
Results: In the control arm, there were several hundred changes in gene expression in non-neoplastic tissue during the 12-months. These were associated with increase in expression of potentially oncogenic pathways including inflammation processes and epithelial-mesenchymal-transition. Changes in gene expression and associated oncogenic pathways were attenuated in men on the glucoraphanin-rich broccoli soup in a dose dependent manner. While the study was not powered to assess clinical progression, an inverse association between consumption of cruciferous vegetables with cancer progression was observed.
Conclusions: Consuming glucoraphanin-rich broccoli soup affected gene expression in the prostate of men on active surveillance, consistent with a reduction in risk of cancer progression.

AJCN

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