This phase II trial tests whether broccoli seed and sprout extract works to break down cancer causing substances of tobacco in heavy smokers. Smokers are at increased risk for developing lung, head and neck, and other cancers. Broccoli seed and sprout extract may help break down and remove toxic substances caused by tobacco use and possibly produce substances that may protect cells from tobacco smoke-induced damage in current smokers.
Male or female current tobacco smokers with >= 20 pack years of self-reported smoking exposure and a current average use of >= 10 cigarettes/day
Age >= 18 years. No upper age limit
Karnofsky performance scale >= 70%
Absolute neutrophil count >= 1,000/microliter
History of invasive cancer within the past 2 years, except for excised and cured non-melanoma skin cancer or carcinoma in situ of the cervix. Participants who continue adjuvant treatment for an index cancer occurring > 2 years ago, such as adjuvant hormonal therapy for breast cancer, are excluded. Participants who are on anti-neoplastic treatment for a chronic malignancy, such as multiple myeloma or chronic myelogenous leukemia, are excluded
Ongoing use of a nutraceutical or dietary supplement containing glucoraphanin or sulforaphane
Note, participants will be eligible if they agree to stop the glucoraphanin or sulforaphane product at least 7 days prior to the baseline visit (7-day washout)
Participants with known chronic hepatitis B virus (HBV) infection are not eligible for this trial due to potential interaction between sulforaphane and suppressive anti-viral therapy