Blood test for oral cancers caused by HPV may be on horizon
HPV, the most common sexually transmitted disease, can lead to throat cancer. Doctors have been warning about the link for years, and earlier this month, Michael Douglas thrust the health risk to international attention by disclosing his 2010 bout with cancer was caused by a strain of HPV transmitted through oral sex.
Recent reports suggest these HPV-driven cancers of the throat, tonsils and base of the throat -- called oropharyngeal cancer --are on the rise, and doctors point out people who are now getting diagnosed with the cancer likely had gotten HPV more than a decade earlier.
Now, government researchers have found what they are calling a promising biomarker, or cellular signal of a disease or condition, that may predict who will develop this cancer more than 10 years before diagnosis. They hope their findings can one day turn into a blood test that screens for oropharyngeal cancer caused by HPV.
"If the predictive capability of the (test) holds up in other studies, we may want to consider developing a screening tool based on this result," study author Dr. Paul Brennan, a scientist at the World Health Organization's International Agency for Research on Cancer (IARC), said in a press release.
HPV, or human papillomavirus is a disease that can be spread through oral or genital sex. HPV is so common, nearly all sexually-active men and women will get it at some point in their lives, the Centers for Disease Control and Prevention points out. There are more than 100 strains of HPV, about 40 of which that can infect the genitals of men and women, potentially causing warts and other health issues. Ninety percent of HPV infections go away by themselves within a couple years, and most people with the disease won't develop health problems. But, some strains of HPV can persist and lead to genital warts and cancers of the oropharynx, cervix, vulva, vagina, penis and anus.
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The 2013 Annual Report to the Nation on the Status of Cancer showed oropharyngeal cancer has been steadily on the rise over the past decade in men and women. In 2009 alone, 13,000 new cases of oropharyngeal in both men and women linked to HPV, more than 10,500 of which were in men.
Previously, the cancers were thought for the most part to be caused by smoking and drinking, but according to the new study's authors, more than 60 percent of oropharyngeal cancers were caused by HPV, particularly the HPV16 strain.
"There's an epidemic of HPV-related throat cancers,"Dr. Eric Genden, professor and chair of otolaryngology at Icahn School of Medicine at Mt. Sinai Hospital in New York City, told CBSNews.com in June following Douglas' cancer announcement.
Health officials say vaccination can protect against some cancer-causing strains of HPV.
Researchers at the IARC collaborated with the National Cancer Institute of the U.S. to analyze blood samples from more than 500,000 European adults who were part of a long-running nutrition study. From those, they picked 135 people who developed oropharyngeal cancer between one and 13 years of getting the blood test, and compared their blood samples to 1,600 healthy control subjects who did not develop cancer.
That's when they found antibodies, or proteins indicative of an immune system response, against HPV E6, a gene on the virus that's been shown in previous studies to cause tumors to form. They found these antibodies against the HPV16 E6 in one out of three people who developed oropharyngeal cancer within 13 years, compared to less than 1 in 100 people who didn't get the cancer. Samples had been collected on average six years before diagnosis, but antibodies were found even longer than that.
"Our study shows not only that the E6 antibodies are present prior to diagnosis--but that in many cases, the antibodies are there more than a decade before the cancer was clinically detectable, an important feature of a successful screening biomarker," lead investigator Dr. Aimee R. Kreimer, a researcher at the National Cancer Institute's division of cancer epidemiology and genetics, said in a statement.
The study was published June 17 in the Journal of Clinical Oncology.
Dr. Ellie Maghami, chief of the division of head and neck surgery at the City of Hope National Medical Center in Duarte, Calif., told CNN such a test could boost patient care.
"Perhaps these types of patients could be under closer surveillance, so this potentially allows for more regular screening, early detection, earlier diagnosis and earlier intervention," Maghami, who was not involved in the new research, said.
