Exploring how Japanese Americans metabolize a tobacco carcinogen

STUDY 2: CLINICAL PROTOCOL Metabolism of NNK Among Japanese Americans

Observational Masonic Cancer Center, University of Minnesota · NCT04228952

This study is testing how Japanese American smokers process a harmful chemical in tobacco to see if their genetics affect their risk of lung cancer.

Quick facts

Study typeObservational
Enrollment50 (estimated)
Ages21 Years and up
SexAll
SponsorMasonic Cancer Center, University of Minnesota Academic / other
Locations1 site (Honolulu, Hawaii)
Trial IDNCT04228952 on ClinicalTrials.gov

What this trial studies

This observational study investigates the metabolism of a tobacco-specific lung carcinogen, NNK, among Japanese American smokers. Participants will smoke specially prepared cigarettes containing deuterium-labeled NNK for seven days, during which urine and blood samples will be collected to analyze NNK metabolic profiling. The study aims to understand how genetic variations in the CYP2A6 enzyme influence the metabolism of NNK and potentially contribute to lung cancer risk in this population. By examining these metabolic differences, the research seeks to shed light on the varying risks of lung cancer among different ethnic groups.

Who should consider this trial

Good fit: Ideal candidates for this study are Japanese American daily smokers aged 21 and older with specific CYP2A6 activity levels.

Not a fit: Patients who do not identify as Japanese American or who do not meet the smoking and health criteria may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to better understanding and prevention strategies for lung cancer in Japanese Americans.

How similar studies have performed: While studies on tobacco metabolism exist, this specific focus on Japanese Americans and the use of deuterium-labeled NNK is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Japanese American - one, but preferably 2 biological parents of Japanese descent
2. 21 years or older
3. Daily smoker
4. Eligible urinary ratios of total 3-hydroxycotinine to cotinine (3HC/COT):

   * "Little or no-CYP2A6 activity" defined as a 3-hydroxycotinine:cotinine ratio of \<0.6 or
   * "Relatively high" CYP2A6 activity defined as a 3-hydroxycotinine:cotinine ratio of \>3.0.
5. Stable and good physical and mental health
6. Provided written informed consent to participate in the study

Exclusion Criteria:

1. Unwilling to avoid other nicotine containing products during the study and no use of any nicotine-containing products except cigarettes for 1 week prior to their study visits
2. Currently taking any medications that affect relevant metabolic enzymes
3. Experiencing medical conditions that might affect biomarkers of exposure and effect
4. Pregnant or nursing or planning on becoming pregnant during the study
5. Unable to read and understand English

Where this trial is running

Honolulu, Hawaii

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions SmokingCYP2A6, Nicotine Metabolite Ratio, NNAL, NNK α-hydroxylation
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.