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Roxanne Nelson – staff journalist for Medscape Oncology.

The incidence of oral tongue squamous cell carcinoma has been rising in young white American women, according to a new report. For the past 3 decades, the incidence has been increasing in white men and white women 18 to 44 years of age, but the trend is most pronounced in young white women.

In a report published online March 7 in the Journal of Clinical Oncology, the authors found that the incidence of oral cavity squamous cell carcinoma was declining for all age groups. The incidence of oral cavity and tongue cancer also was decreasing for nonwhite individuals. However, among people 18 to 44 years of age, the incidence of oral tongue cancer climbed 28% between 1975 and 2007. Among white people in this age group, the incidence increased 67%. The rising rates were most dramatic for white women, with a jump of 111%.

“Lately, we have been seeing more oral tongue cancer in young white women in our clinic. So we looked at the literature, which reported an increase in oral tongue squamous cell carcinoma in young white individuals, but couldn’t find any information about gender-specific incidence rates, so we decided we should take a look at the SEER [Surveillance, Epidemiology, and End Results] data,” said lead author Bhisham Chera, MD, assistant professor in the Department of Radiation Oncology at the University of North Carolina School of Medicine, Chapel Hill. The authors note that historically, cancer of the oral cavity was considered to be associated with older men with histories of significant tobacco and alcohol use. But during the past 30 years, the incidence of oral cavity squamous cell carcinoma has been declining while the incidence of oropharyngeal squamous cell cancer has been increasing. These trends, note the authors, might be explained by the decreased use of tobacco and the association between the carcinogenic strains of human papillomavirus (HPV) and cancer of the oral cavity.

Not HPV Associated

Unlike cancers of the tonsil and base of tongue subsites within the oropharynx, oral cavity and oral tongue squamous cell carcinomas are rarely associated with HPV infection, according to the authors. The demographics of HPV-related head and neck malignancies differ from those associated with HPV. Those with HPV-associated head and neck cancers generally tend to be white men who are nonsmokers. At Dr. Chera’s institution, the young patients with head and neck squamous cell carcinomas who are nonsmokers and nondrinkers are most likely to be white women with oral cavity squamous cell carcinoma.

“Our findings suggest that the epidemiology of this cancer in young white females may be unique and that the causative factors may be things other than tobacco and alcohol abuse,” Dr. Chera said. “Based on our observations and the published data, it appears that these cases may not be associated with the human papillomavirus. We are actively researching other causes of this cancer in this patient population.”

They have examined the HPV status of their young white female patients with oral tongue tumors and have not found an association. Other reports have shown similar findings — a higher number of oral tongue squamous cell carcinomas in women and an absence of detectable HPV DNA. It is possible that they are being caused by a different virus or another subtype of HPV, he told Medscape Medical News. “There are over 100 subtypes but only handful are associated with malignancy, and we only test for the high-risk types.”

“Could it be that another type is associated? . . . Basically, we don’t know yet,” Dr. Chera added. In their study, Dr. Chera and colleagues analyzed the incidence and survival data from the SEER Program from 1975 to 2007 for oral cavity squamous cell carcinoma and oral tongue squamous cell carcinomas. Specifically, they looked at 3 cohorts: patients of all ages, patients 18 to 44 years of age, and patients 44 years and older. The patients were also stratified by sex and/or race.

Possible Emerging Clinical Entity

During that time period, SEER data showed 32,776 cases of oral cavity squamous cell carcinoma, with 2223 of those occurring in young adults. The ratios for male/female and white/black or other races were 2.2:1.0 and 8.5:1.0, respectively. For all age groups, there were a total of 6,810 cases of oral tongue squamous cell carcinoma, with 814 in the 18 to 44 year age group. For all age groups, the male/female ratio was 1.6:1.0; stratified by race, 424 were white (82%), 50 (6%) were black, and 96 (12%) were other. Because it is not usually associated with HPV, the authors note that oral tongue squamous cell carcinoma in young white women “may be an emerging and distinct clinical entity, although future research is necessary before broad conclusions can be drawn.” Specifically, further investigation is needed to examine the sources of the observed variation, they write.

“Dentists and primary care physicians should be more cognizant of oral tongue squamous cell carcinoma in this group of patients,” said Dr. Chera. “At this point, the incidence is very small, and widespread screening may not be cost effective.”

“I would say that if a young white person has complaints of a persistent sore on their tongue, cancer should be moved up higher on the differential, based on our study,” he added. “Dentists should not only examine dental health but also examine the tongue. They are in a position to provide effective screening.”

The source for this article was – J Clin Oncol. Published online March 7, 2011. Abstract