by Bob Roehr
Human papillomavirus (HPV), which causes cervical, vaginal, and anal cancers, has long been implicated in the development of oropharyngeal or throat cancer. The most recent demonstration of that came on May 10 in a study published in the New England Journal of Medicine.
It was conducted at Johns Hopkins University from 2000 to 2005 and involved 100 persons with throat cancer. It found that 72 percent of the tumors contained HPV-16 DNA – one of the most common of the more than 100 types of the virus – which is responsible for the largest number of cancers in other tissue.
The cancer was significantly more likely to occur in men than women (86 percent vs. 14 percent). The factors most clearly associated with its occurrence were a larger number of sexual partners and engaging in oral-vaginal sex. The study could not rule out the possibility that the virus could be spread through direct mouth-to-mouth contact or by other means.
Only 8 percent of the study participants acknowledged ever having had sex with a partner of the same sex, and 87 percent were non-Hispanic whites, so it is difficult to say with certainty that the findings apply to persons other than white heterosexual males.
However, the biological ways that HPV-16 is transmitted and develops into cancer in other tissues does not appear to differ by sex, race, or ethnicity. So it is reasonable to assume that the findings apply to all persons.
A history of heavy use of tobacco, alcohol, or marijuana were also associated with the development of throat cancer. However, there did not appear to be a synergy between use of these substances and infection with HPV-16. This led the researchers to suggest that there are "two distinct pathways for the development of oropharyngeal cancer."
While some will no doubt obsess about this new data, and social conservatives will point to it as yet another reason to push for abstinence, the fact is, oropharyngeal cancer is rare. An estimated 120,000 cases a year are believed to occur among 6 billion people worldwide.
Gardasil, the recently approved vaccine against HPV, is extremely effective at preventing vaginal and cervical cancer. It is being evaluated in the prevention of oropharyngeal cancer as well. There is no biological reason why it should not be as effective in that tissue compartment. The study authors said this provides yet another rationale for vaccinating boys as well as girls with the vaccine.
Herpes
Chronic infection with herpes simplex virus, a family of viruses that range from cold sores on the lips or genitals, to chickenpox, to Kaposi's sarcoma, may be good for you in some ways.
The surprising discovery was made by scientists working with mice at the Washington University School of Medicine in St. Louis. They found the immune system of infected animals produced higher levels of interferon gamma. This protected them against infection from other pathogens that cause food poisoning and the plague, and resulted in much milder and less lethal disease processes.
They speculated that it might be part of the ongoing mutual co-evolution of humans and the viruses that can infect them. Some of those viruses became a permanent part of human DNA tens of thousands of years ago. The paper appeared in the journal Nature.
