RISK OF HPV OROPHARYNGEAL CANCER

The risk of developing oropharyngeal cancer (OPC) related to oral human papillomavirus (HPV) infection is very low in the general population and even in people with specific behavioral risk factors, a new study suggests.

"Oropharyngeal cancer has been in the news lately. The incidence of oropharyngeal cancer has doubled over the past several decades, but this research is very reassuring in showing that the cancer does remain rare," first author, Gypsyamber D'Souza, PhD, from the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, told Medscape Medical News.

"Our study identified some risk factors for oral HPV infection, but even among the highest-risk groups — people who were middle-aged, male, and current smokers — their chances of having an infection and having that infection progress to cause cancer remain low," Dr D'Souza said.

The study was published online October 20 in Annals of Oncology.

The researchers analyzed data from 2009 to 2014 for 13,089 adults aged 20 to 69 years participating in the National Health and Nutrition Examination Survey (NHANES), including oral HPV data, and OPC case data from Surveillance, Epidemiology, and End Results (SEER) registries.

The prevalence of oral infections with the 12 oncogenic HPV types was low in every defined age group, the researchers report. Women aged 20 to 69 years had a frequency of infection of 1.1% compared with 6.0% for men aged 20 to 69 years. The highest prevalence of any oncogenic HPV type was in women and men aged 50 to 59 years (1.6% and 8.1%, respectively). Oral HPV 16 prevalence was also low on average in all groups, ranging from 0.1% in women aged 60 to 69 years to 2.4% in men in their 60s.

Of note, a study published last week found generally higher rates of oral HPV of any type, as well as high-risk, oncogenic HPV types, in all ethnic groups of men in the United States; the study used the same NHANES source, but for the years 2011 to 2014.

As expected, report Dr D'Souza and colleagues, the prevalence of oncogenic oral HPV was higher in men than women and increased with the number of lifetime oral sex partners and tobacco use. Oncogenic oral HPV prevalence was 14.9% in men who smoked and had five or more lifetime oral sex partners compared with 7.3% in men with only one of these risk factors (ie, those who either smoked and had two to four partners or those did not smoke and had  five or more partners).  Oncogenic oral HPV prevalence was low among men and women with only one or no lifetime oral sexual partner (1.7% and 0.7%, respectively), regardless of other risk factors.

Importantly, say the authors, while oncogenic oral HPV was detected in 3.5% of all adults (men and women) aged 20 to 69 years, the lifetime risk for OPC was only 37 per 10,000, based on the SEER data.

For example, among men aged 50 to 59 years, 8.1% have an oncogenic oral HPV infection, 2.1% have an oral HPV 16 infection, yet only 0.7% will "ever" develop OPC in their lifetime, the authors calculate.  Their risk of developing OPC in the next 10 or 20 years is even lower (0.2% and 0.4%, respectively).  For women, the lifetime risk is 0.2%.

Overall, "the data should be reassuring that oropharyngeal cancer remains a rare cancer," Dr D'Souza said.

The data should be reassuring that oropharyngeal cancer remains a rare cancer. Dr Gypsyamber D'Souza

On the basis of their findings, the researchers say the value of screening for oral oncogenic HPV infection at this time would be "limited" in most groups. "Because most people who have an oral HPV infection will clear that infection on their own within a year or two suggests that we should not be screening for it and there are no FDA [Food and Drug Administration]-approved screening tests," Dr D'Souza said.

Another Point of View

Reached for comment, Mark Persky, MD, professor of otolaryngology–head and neck surgery and director of NYU Langone's Head & Neck Center, New York City, urged caution in concluding that OPC is rare. 

"This is an important study published in a peer-review journal by a very reputable group. The results are not surprising, but the low risk they found I would not term as 'rare'," he noted in an interview with Medscape Medical News. "It may be infrequent, but it doesn't fall into the rare category, and I don't think we should give the public that perception," Dr Persky said.

The low risk they found I would not term as 'rare.' Dr Mark Persky

"The most important thing, as a last line to this whole thing," he said, "is that there is no question that the medical profession has to emphasize and the public has to realize the importance of the HPV vaccine."