TUESDAY, April 29, 2014 (HealthDay News) -- Romantic intimacy in long-term relationships often suffers when one partner gets a diagnosis of mouth or throat cancer caused by HPV, the sexually transmitted human papillomavirus. But new research suggests these couples can kiss as much and as deeply as they ever have, without worry.
Spouses and long-term partners of patients with HPV-related oral cancers appear to have no increased risk of oral HPV infections, according to the results of a new study led by Johns Hopkins investigators.
Saliva samples taken from the partners of oral cancer patients did not contain elevated levels of HPV DNA, the researchers reported online April 28 in the Journal of Clinical Oncology.
The prevalence of HPV among spouses and partners -- about 1.2 percent -- is comparable to the 1.3 percent prevalence of HPV among the general population of the same age, the researchers found.
Experts welcomed the findings.
"This study does put the risk in perspective. It's not something you need to freak out about, or substantially alter your lifestyle. You can still smooch your sweetie," said Fred Wyand, spokesman for the American Sexual Health Association.
HPV-related oral cancers are increasing among white men in the United States, with the virus now associated with nearly three out of four cases of oropharyngeal cancer, according to a 2011 report in the Journal of Clinical Oncology. These include cancers of the base of the tongue, tonsils, soft palate and pharynx. Although sexual behavior is associated with oral HPV infection, it's not fully clear how the cancer-causing virus is transmitted or progresses, according to background information in the new report.
Once diagnosed, fear of HPV transmission can lead to anxiety, divorce and curtailing of sex and intimacy among couples, said the study's lead author, Gypsyamber D'Souza, associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.
New York City oncologist Dr. Dennis Kraus said it's normal for older couples in long-term relationships to become unsettled by the news that one of them has mouth and throat cancer caused by a sexually transmitted virus.
"They think, 'What kind of a relationship am I involved in? Who is this person?' Many of them have grandchildren and even great-grandchildren and now they have to be worried about their progeny being exposed to this disease," said Kraus, director of the Center for Head and Neck Oncology at Lenox Hill Hospital.
To confront these concerns, researchers took mouth-rinse samples from 164 patients with HPV-related oropharyngeal cancer and 93 partners. They then ran DNA tests for 36 strains of HPV.
Nine out of 10 of the oral cancer patients were men, and nearly all had performed oral sex in the past. They were in their 50s and early 60s.
More than half of the cancer patients had detectable HPV in their saliva at the time of the test, but the virus showed up in only 1.2 percent of the partners tested.
"While oral HPV DNA was common in people with cancer, their spouses did not have an elevated prevalence," D'Souza said. "That suggests either oral HPV is not being transmitted in the saliva when the partners kiss, or they have effectively cleared the infections they've been exposed to."
D'Souza said that most people clear HPV infections within a year or two, and persistent infections can take many years to lead to cancer.
"Partners who have been together for many years have already shared any infections they are going to share," she said.
However, new romantic partners should know that they stand a chance of being infected with oral HPV, even though the infection may not be long-lasting, said Dr. Snehal Bhoola, a gynecologic oncologist with Arizona Oncology, a US Oncology Network affiliate in Phoenix.
"It is possible that HPV may be transmitted to new partners, but this appears to be cleared within one to two years in the majority of patients," Bhoola said. Female partners of HPV-positive patients should continue routine cervical cancer screening per recommended guidelines, he added.
While most people acquire an oral HPV infection by performing oral sex, researchers have not yet tackled whether it can work the other way -- a person with oral HPV transmitting the virus to their partner's genitals during oral sex, D'Souza said.
For more information on HPV, visit the U.S. Centers for Disease Control and Prevention.