Clinical Trial of Lung Cancer Chemoprevention With Sulforaphane in Former Smokers

Inclusion Criteria: 1. Man or woman 55-75 years of age. 2. Patients with normal endobronchial biopsy findings or pre-cancerous lesions at baseline will be eligible for the study. Pre-cancerous lesions include (a) reserve cell hyperplasia, (b) squamous metaplasia, (c) mild dysplasia, (d) moderate dysplasia, and (e) severe dysplasia. 3. A former smoker who has a history of smoking with ≥30 pack-years, quits smoking within the past 10 years, and has ≥1 year sustained abstinence from smoking. 4. Female subjects must be of non-child bearing potential or must have a negative serum pregnancy test at screening (within 72 hours of first dose of study medication) if of childbearing potential. 5. Male and female subjects of childbearing potential must be willing to use adequate barrier methods of contraception from the time starting with the screening visit through 30 days after the last dose of study therapy. 6. Abstinence is acceptable if this is the established and preferred contraception for the subject. 7. Generally healthy with liver enzyme and blood count values within the ranges shown below on the blood sample drawn at the baseline screening visit. Specifically: White blood cells ≥ 3,000/mL Total bilirubin ≤ 1.5 x ULN (upper limits of normal) AST (SGOT)/ALT (SGPT) ≤ 2.5 x ULN BUN and serum creatinine ≤ 1.5 x ULN Serum pregnancy test Negative 8. The presence of airflow obstruction on spirometry (GOLD II or greater, Forced Expiratory Volume in the first second (FEV1) \<80%) Chronic Obstructive Pulmonary Disease (COPD); and/or any emphysema on CT scan. 9. Participants must have a Southwest Oncology Group (SWOG) performance status of 0-2 10. Participants must be able and willing to undergo a bronchoscopy before and after treatment for 12 months. 11. Patients must be fully informed of the investigational nature of this study and must sign an informed consent in accordance within institutional and regulatory guidelines. Exclusion Criteria: 1. Carcinoma in situ or invasive cancer on baseline endobronchial biopsy. 2. A malignancy except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer. 3. Severe lung disease or inability to undergo two bronchoscopies. 4. Had pneumonia or acute bronchitis for at least 2 weeks prior to enrollment. 5. Cardiac dysrhythmia that is potentially life-threatening, such as ventricular tachycardia, multifocal premature ventricular contractions or supraventricular tachycardias with a rapid ventricular response. Well-controlled atrial fibrillation or rare (\< 2 minutes) premature ventricular contractions are not exclusionary. 6. Evidence of clinically active coronary artery disease, including myocardial infarction within 6 weeks, chest pain, or congestive heart failure, or any serious medical condition which would preclude a patient from undergoing a bronchoscopy or would jeopardize the goals of the study. 7. Hypoxemia (less than 90% saturation with supplemental oxygen). 8. Prior chemotherapy or thoracic radiation within the past 5 years. 9. Woman who is pregnant or plan to be pregnant in next 12 months, or is breast feeding or plan to begin breast feeding in next 12 months. 10. Life expectancy of \< 12 months. 11. Have a history of irritable bowel disease such as Crohn's disease and ulcerative colitis.