Oral verrucous carcinoma. Incidence in two US populations.

Much is known about the clinical appearance, biological behavior, and treatment of verrucous carcinoma of the oral cavity. However, the epidemiologic characteristics are completely unknown. This cancer is considered to be rare in Western cultures because it is not common in oral pathology biopsy services, but there is no epidemiologic evidence for this belief. To provide this evidence, 2 population-based incidence investigations were carried out, one in Rochester, Minn., and the other in the state of West Virginia. The results were as follows: the age-adjusted average annual incidence rate for oral verrucous carcinoma among Rochester residents was 0.1/100,000 person-years (0.2 for males, 0.0 for females), whereas the incidence rate for all intraoral carcinomas was 3.6/100,000 person-years (5.4 for males, 2.1 for females). Among men over 64 years of age, the incidence rate for verrucous carcinoma was increased to 3.2/100,000 person-years. Verrucous carcinoma was among the least common of the oral carcinomas in this population, representing only 3% of the total. The age-adjusted incidence rate for oral and pharyngeal verrucous carcinoma among West Virginia residents was somewhat greater, 0.3/100,000 person-years, and showed an even gender predilection (0.28 for males, 0.29 for females). The incidence rate for all oral/pharyngeal cancers in West Virginia was 8.8/100,000 person-years (13.4 for males, 5.7 for females), which was below the US average. The conclusion is that oral verrucous carcinoma is a rare tumor of older people, diagnosed in only 1 to 3 of every 1,000,000 persons each year.