CHICAGO – Partners of patients with human papillomavirus-positive oropharyngeal cancer do not appear to be at an increased risk for HPV-related cancers, investigators reported at the annual meeting of the American Society of Clinical Oncology.
Of 88 female partners of persons with HPV-positive oropharyngeal cancers, 4 were found to be positive for HPV infection, and 2 of the 4 were positive for the oncogenic HPV-16 subtype. The prevalence of HPV infection in this sample was 5%, similar to that of women in the general population (3.6%), reported Gypsyamber D’Souza, Ph.D., an epidemiologist at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Md.
None of the male partners in this small pilot study tested positive for oral HPV 16, but the male sample size was too small to draw significant conclusions about the risks of HPV transmission in men, Dr. D’Souza said.
"This is the first study to examine oral HPV prevalence among spouses of HPV-related oropharyngeal cancer patients, and it’s very reassuring that the oral HPV prevalence was similar to that observed in the general population. This suggests that risk of HPV-related cancer remains low among these spouses," she said in a media briefing prior to her presentation.
The study also supports epidemiologic data showing that although HPV infections are common in the general population, the overwhelming majority of people who are infected will spontaneously clear the virus and not get cancer.
"We certainly will need longer follow-up on how HPV infection and co-infection in the partners will affect patients and the development of cancer, but we recognize this as an important breakthrough in the understanding of the biology of oropharyngeal cancer," commented Dr. Gregory Masters, a medical oncologist at the Helen F. Graham Cancer Center in Newark, Del., who moderated the briefing.
Dr. Marcia S. Brose, a head and neck surgeon at the Hospital of the University of Pennsylvania in Philadelphia, said that despite the handful of male partners, the study sends an important message to patients and their partners.
"As oncologists, we’re not just in the business of the disease itself; we also have to treat the family members and their concerns. If you’re the spouse of someone who has a communicable disease-related cancer, you’re going to have to make decisions that affect your private life, and it means a lot that someone is doing the research that says you don’t have to worry," she said in an interview.
The study was prompted by concerns frequently expressed by patients with oropharyngeal cancer and their spouses/sexual partners about oral transmission of HPV and increased cancer risk, Dr. D’Souza said.
The investigators enrolled 147 men and 19 women (median age 56) with oropharyngeal cancers, and 94 of their spouses or long-term partners.
Oral rinse and gargle samples were collected from all cases and partners in the study at baseline and 1 year later. The samples were tested for the presence of HPV DNA. Imperfect as it is in sensitivity and specificity for HPV, the test is nonetheless the gold standard for detecting HPV in oral cancers, Dr. D’Souza said.
At the time of diagnosis, 65% of patients tested positive for HPV, and 54% of all patients had HPV 16.
At 1 year, however, following completion of therapy, only 5.6% of patients still tested positive for HPV 16.
Overall, the prevalence of oral HPV among partners was 6.5%, comparable to HPV prevalence among the general population in National Health and Nutrition Examination Survery (NHANES) data from 2009-2010. Among male partners, the prevalence of HPV also was similar to that seen among men in the general population (10.1%), but the small number made it difficult if not impossible to draw meaningful conclusions.
No oral or oropharyngeal cancers were detected in partners in an oral cancer screen, but three patients reported having previous partners with oropharyngeal cancer. In addition, five male patients reported having a partner who developed cervical cancer or a precancerous condition (one current partner and two previous partners had cervical cancers, and two current partners had cervical dysplasia).
The study was supported by the Johns Hopkins Innovation Fund. Dr. D’Souza reported receiving research support from Merck, maker of Gardasil.