Randomized Phase II Clinical Trial of Sulforaphane in Former Smokers at High Risk for Lung Cancer

Area of Science:

• Oncology
• Nutritional Science
• Preventive Medicine

Background:

• Dietary isothiocyanates show promise in preclinical models, reducing proliferation and increasing apoptosis.
• Human data on isothiocyanates, specifically sulforaphane, for bronchial health are limited.
• Previous studies suggest a link between cruciferous vegetable intake and reduced lung cancer risk.

Purpose of the Study:

• To evaluate sulforaphane's effect on bronchial histopathology, Ki-67, caspase-3, and TUNEL indices in former smokers.
• To determine if sulforaphane can halt or reverse bronchial histopathological changes.
• To assess sulforaphane's potential as a chemopreventive agent for lung cancer.

Main Methods:

• A 12-month randomized clinical trial (NCT03232138) involving 43 former smokers.
• Participants received either a placebo or 95 micromol of sulforaphane daily.
• Endpoints included changes in bronchial histopathology, Ki-67, caspase-3, and TUNEL indices via biopsy analysis.

Main Results:

• Sulforaphane did not significantly alter bronchial histopathology.
• A significant reduction in the Ki-67 proliferation index was observed in the sulforaphane group (20% decrease) compared to the placebo group (65% increase; P = 0.014).
• Higher sulforaphane bioavailability correlated with a greater reduction in Ki-67 index (P for trend = 0.019).
• No significant impact on caspase-3 or TUNEL indices was found.
• No severe adverse events were reported.

Conclusions:

• Oral sulforaphane supplementation significantly reduced the Ki-67 index in bronchial tissue of former smokers.
• The reduction in Ki-67 suggests a potential role for sulforaphane as a lung cancer chemopreventive agent.
• Further research is warranted to explore sulforaphane's efficacy in lung cancer prevention.