Record ID: MS-N092
Family: Botanicals and nutraceuticals
Clinical question: Does oral sulforaphane slow biochemical recurrence after radical prostatectomy?
Evidence label: Randomized trial; negative primary endpoint with secondary PSA signals
Evidence at a glance
Benefit: The prespecified log-PSA-slope endpoint was not met; several secondary PSA measures favored sulforaphane.
Certainty: Low. One modest trial, surrogate endpoints and multiple secondary analyses.
Risk: Mostly mild gastrointestinal effects in the trial; commercial broccoli-sprout products may not deliver the standardized free sulforaphane dose.
Cancer control: No evidence from this trial establishes delayed metastasis, avoidance of salvage therapy or longer survival.
What was studied
A multicenter double-blind trial randomized 78 men with rising PSA after prostatectomy to stabilized free sulforaphane 60 mg/day or placebo for six months, followed by two months off treatment. Seventy-five had all four scheduled PSA measurements.
A separate single-arm phase II study gave sulforaphane-rich broccoli-sprout extract supplying 200 micromoles/day to 20 men for up to 20 weeks; its primary endpoint was a PSA decline of at least 50%.
What the results mean
The randomized trial’s primary endpoint—a prespecified difference in log PSA slope using months 0, 1, 3 and 6—was not met (P=.11). Secondary analyses showed a smaller mean PSA increase (+0.099 versus +0.620 ng/mL; P=.0433), longer calculated PSA doubling time and fewer rises greater than 20% (44.4% versus 71.8%).
In the single-arm study, no participant achieved the primary 50% PSA decline. PSA doubling-time changes without a control group remain exploratory.
Limits and uncertainty
The positive findings were secondary analyses after a negative primary endpoint. PSA kinetics are useful for research but cannot by themselves prove that a supplement delays symptoms, metastasis or death.
The formulations—stabilized free sulforaphane and a broccoli-sprout extract—are not interchangeable with broccoli foods or arbitrary supplements.
Safety and practical context
Adverse events were reported by 52.5% of sulforaphane recipients and 36.5% of placebo recipients; most were grade 1–2. Bloating was somewhat more common, and one participant withdrew for bowel discomfort. No grade 3–4 events were reported.
Do not postpone salvage-radiation or androgen-deprivation discussions on the basis of PSA-slope signals.
Questions for the care team
- Did the study meet its primary endpoint?
- Does the product deliver stabilized free sulforaphane or only list broccoli-sprout weight?
- What is my evidence-based plan for biochemical recurrence?
- Would a trial measure metastasis-free survival or only PSA kinetics?
Sources
- Randomized sulforaphane trial (PMID 25968598)
- Single-arm broccoli-sprout extract study (PMID 25431127)
Funding and conflicts
Complete funding and conflict details were not verified from full text for this appraisal. The exact standardized formulation is essential to interpretation.
Last literature search: October 21, 2026
Record appraised: October 21, 2026
This educational record is not individualized medical advice. Research doses and schedules are not personal prescriptions; do not delay or replace evidence-based cancer care.
