Gypsyamber D’Souza, PhD, MPH, MS
Patients with human papilloma virus–positive oropharyngeal cancer (HPV-OPC) and their spouses may find some reassurance in a recent study by researchers at the Johns Hopkins Bloomberg School of Health. The study found that partners are no more likely to be infected by HPV than the general population, and their risk of contracting HPV-OPC remains low.
Findings of this pilot study—the first large study to examine oral HPV infection among patients with HPV-OPC and their partners—were announced in press briefing June 1 at ASCO’s 49th Annual Meeting in Chicago.
The majority of oropharyngeal cancers in the US are now caused by HPV, and the incidence of HPV-related oropharyngeal cancer is increasing significantly, noted the study’s lead author, Gypsyamber D’Souza, PhD, MPH, MS, associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. “Some of the patients with this diagnosis worry about oral HPV transmission and the cancer risk to their partners or spouses.”
To better understand this possible increased risk, D’Souza and colleagues enrolled a total of 166 patients with HPV-OPC; 94 of them had spouses or long-term partners who were also enrolled in the study. DNA samples were collected from both groups, following administration of a 30-second mouth rinse and gargle. Samples were obtained at the time of diagnosis and 1 year later.
Median age of the HPV-OPC patients was 56 years; 89% were male, 92% were white, non-Hispanic, and 94% had performed oral sex. Their partners were predominantly female (94%) and white, non-Hispanic (92%), with a median age of 53 years. Patients were significantly more likely to have had >10 oral sex partners over their lifetime (39%), versus their spouses/partners (11%).
Samples were analyzed for the presence of 36 subtypes of HPV DNA, among them, the most prevalent type found in the majority of HPV-OPC cancers—HPV16. DNA is considered the “gold standard” for determining presence of HPV in the tumor, D’Souza explained. She noted that for individuals without cancer, examining exfoliated oral cells from the rinse/gargle samples is the best available option for measuring oral HPV infection, since there is currently no validated, FDA-approved test.
Researchers found that nearly two-thirds of the cases (65%) had HPV DNA in their oral exfoliated cells, and a little over half (54%) of these cases had HPV16, said D’Souza. After 1 year and completion of treatment, analysis of the oral rinse samples from the HPV-OPC cases demonstrated that a “vast majority of these cases no longer had any HPV16 DNA detectable,” she added.
The prevalence of HPV among the long-term female partners of patients was 5%, which is comparable to the 4% prevalence among women in the general population, based on previously published data. HPV16 was found in just 2.3% of female partners and in none of the small number of male partners. In addition, no pre-cancers or cancers were detected in the 60 partners/spouses who underwent a visual oral exam.
“These findings provide assurance that prevalence of oral HPV infection is not increased among partners [of patients with HPV-OPC], and their risk of HPV-OPC remains low,” said D’Souza. “Couples who have been together for several years have likely shared whatever infections they have, and no changes in their physical intimacy are needed.”
D’Souza concluded her presentation by noting that while oral HPV infection remains common, “many individuals who become infected are able to clear these infections and not get cancer.”