Sexual transmission of cancer?

[JesusA (imported)]

The most recent Discover Magazine has an interesting interview with Paul Ewald, one of the leading cancer researchers. He suggests that most human cancers are caused by infection by various pathogens and that sexual transmission seems to be the route of infection for most of them. Do you get cancer from sex?

The Big Idea That Might Beat Cancer and Cut Health-Care Costs by 80 Percent

Paul Ewald says infections are responsible for at least four-fifths of all cancers—and we have the tools to prevent them.

by Andrew Grant

Discover Magazine

September 30, 2009

Below are two questions, and their answers, from the longer interview:

D: How much cancer is caused by viruses or other infectious agents?

PE: If I were going to put my money on it, I would bet that by 2050—hopefully earlier—we’ll have found that more than 80 percent of all human cancer is caused by infection. The number could be as high as 95 percent. In 1975 it was considered to be zero.

D: How do we get infected with these dangerous pathogens?

PE: Two of the most powerful examples are sexual transmission and kissing transmission, and by that I mean juicy kissing, not just a peck on the cheek. If you think about these modes of transmission, in which it might be a decade before a person has another partner, you realize that rapidly replicating is not very valuable—the winning strategy for the microbe would be to keep a low profile, requiring persistent infections for years. So we would expect that disproportionately, the sexually transmitted pathogens would be involved in causing cancer, or chronic diseases in general. You can test this. Just look at the pathogens that are accepted as causing cancer—Epstein-Barr virus, Kaposi’s sarcoma–associated herpes virus, human T lymphotropic virus 1—and find out whether they’re transmitted this way. They almost all are. A random sample would yield maybe 15 to 20 percent of pathogens associated with cancer being sexually transmitted, yet the figure is almost 100 percent. When you look at viruses alone, it is 100 percent.

http://discovermagazine.com/2009/new-sc ... 0-percent/