Avmacol is an over-the-counter dietary supplement containing broccoli seed and sprout extracts in tablet form, hypothesized to activate protective cellular pathways including detoxication. In this study, participants who have been curatively treatment for head and neck cancer, will take Avmacol twice a day for 3 months.

The broccoli seed preparation, Avmacol®, results in acute and/or sustained induction of NRF2 target gene transcripts in the oral mucosa of patients who have been curatively treated for a tobacco-related head and neck squamous cell carcinoma (HNSCC), including high grade dysplasia, carcinoma in situ, or invasive carcinoma. This study is not designed to examine the therapeutic or reparative effects of Avmacol® on premalignant lesions of the oral cavity.

We will systematically assess the clinical chemopreventive potential of Avmacol® administration to patients with tobacco-related HNSCC at high risk for second primary tumor by:

1. Conducting this phase 0 clinical study to evaluate the pharmacodynamic range of NRF2 pathway activation in the oral mucosa of HNSCC patients, in response to two tolerable and bioactive doses of Avmacol®;
2. Determining whether the level of NRF2 pathway activation achieved in human oral epithelium is chemopreventive in the NQO1 murine model of environmental carcinogenesis; and
3. Analyzing specimens from the Phase 0 trial to determine whether Avmacol® induces changes in alternative biomarkers of SF chemopreventive efficacy identified in the laboratory.

Inclusion Criteria:

1. Participants must have completed curative-intent therapy (including surgery, radiation, and/or chemotherapy) for a first tobacco-related oral premalignant lesion (OPL) or HNSCC of any stage (eligible lesions include high grade dysplasia; carcinoma in situ; or stage I-IVa HNSCC).

2. Primary site may include oral cavity, pharynx, or larynx. Oropharynx primaries must be HPV (-) as defined by routine p16 IHC at the local site.

3. Participants may be enrolled between 3 months and 5 years AFTER completion of curative-intent therapy (including surgery, radiotherapy, and/or chemotherapy).

4. Participants may have untreated OPLs (i.e., hyperplasia, dysplasia, carcinoma in situ) at the time of study entry, provided the index OPL or HNSCC was definitively treated.

5. Participants must be at least 18 years old.

6. Participants must have a Karnofsky Performance Status of 80% or higher or an ECOG of 0-1 (Appendix A).

7. Current and former tobacco users are eligible. The tobacco use assessment form must be completed following consent, to assure eligibility (Appendix B). Patients must have ≥10 pack-year cumulative tobacco exposure or its equivalent to be eligible. This is defined as follows:

   1. Cigarette exposure: ≥10 pack-years OR
   2. Cigar exposure: ≥ 10 cigar-years, where 1 cigar year is defined as having smoked on average ≥ 1 cigar/day for a year OR
   3. Chewing tobacco: ≥10 snuff-years, where 1 snuff year is defined as using on average ≥ 1 pinch (dip) of chewing tobacco/day for a year.

8. Able to perform written, informed consent.

9. Women of childbearing potential (WCBP) must have a negative urine pregnancy test within 7 Days prior to the first study intervention.

10. WCBP and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study and for the duration of study participation.

Exclusion Criteria:

1. Participants have a history of another malignancy within 2 years prior to starting study treatment, except for excised and cured carcinoma-in-situ of breast or cervix; non-melanomatous skin cancer; T1-2, N0, M0 differentiated thyroid carcinoma either resected or under active surveillance; superficial bladder cancer; T1a or T1b prostate cancer comprising < 5% of resected tissue with normal prostate specific antigen (PSA) since resection, or status post external beam radiation or brachytherapy with normal PSA since radiation.
2. Primary oropharyngeal HNSCC which is HPV (+) as defined by p16 IHC.
3. Participants with acute intercurrent illness or those who had major surgery within the preceding 4 weeks unless they have fully recovered.
4. Participants who have a positive pregnancy test, are pregnant, or breast feeding.
5. Patients who are not practicing adequate contraception are ineligible if they are of child bearing potential.
6. Patients currently using anti-neoplastic or anti-tumor agents, including chemotherapy, radiation therapy, immunotherapy, and hormonal anticancer therapy.
7. Chronic anticoagulation with warfarin. Patients on low molecular weight heparin or fondaparinux may be enrolled.
8. Use of chronic prescribed medications which are potent inducers or inhibitors of CYP3A4 (Appendix C).
9. Chronic use of steroids at immunosuppressive doses. (Note, physiologic replacement doses of glucocorticoid or mineralocorticoid are acceptable, eg. prednisone 5-10 mg/day; fludrocortisone 0.1-0.2 mg/day.)
10. History of severe food intolerance to broccoli.