Anil Chaturvedi

NCI, DCEG, IIB

Investigator

PLCO (Learn more about this study)

PLCO-20

Mar 15, 2013

Sexually transmitted diseases and risk of head and neck cancer

Background: Syphilis, a sexually transmitted disease caused by the spirochete Treponema pallidum, has historically been associated with increased risk of cancers of the oral tongue. In fact, leukoplakia, a white patch in the mouth, was initially recognized as a head and neck cancer precursor lesion based on increased risk of malignant transformation among individuals with syphilitic leukoplakic regions in the mouth. Despite the historical nature of this association between syphilis and risk of tongue cancer, no contemporary prospective cohort study has addressed this question.

Proposal: We propose to analyze the association of self-reported history of syphilis and risk of head and neck cancers using data from the PLCO, including both the screening arm and the control arm. Information regarding self-reported history of syphilis was collected as part of the baseline questionnaire for males in PLCO.

Hypothesis: We hypothesize that a history of syphilis will be associated with increased risk of cancers of the oral tongue.

Analysis plan: We will analyze the association of syphilis with head and neck cancer incidence using standard Cox proportional hazards models, after adjustment for head and neck cancer risk factors such as age, race, tobacco, and alcohol use. Analyses will be conducted separately for head and neck cancer subsites—lip, oral tongue, base of tongue, other mouth, oropharynx, other pharynx, and larynx. We would therefore like to request a dataset with all incident head and neck cancer cases. To evaluate the specificity of any observed associations, we will utilize data on self-reported history of gonorrhea, also collected as part of the baseline questionnaire for males in PLCO.