I keep an eye open for reports on HPV, since reading that, while it causes cervical cancer, it’s also linked rather less strongly to genital and anal cancer. I turned up another couple of links tonight. The first from the Mouth Cancer Foundation relates to oral cancer:
A study done by Dr. No-Hee Park showed that the mouth was, at the cellular level, structurally very similar to the vagina and cervix. Both organs have the same type of epithelial cells that are the target of HPV 16 and HPV 18. The majority of oral cancers are cancers of epithelial cells, primarily squamous cell carcinomas, not unlike the cancers that affect the cervix. Dr. Park’s study also showed that smoking and drinking alcohol help promote HPV invasion.. Combine tobacco and alcohol with HPV, and the epithelial cells in the mouth, and you may have the formula for the development of an oral cancer.
A recent study conducted by Dr. Maura Gillison at the Johns Hopkins Oncology Center furthered the premise that HPV is linked with certain types of oral cancer. In 25% of 253 patients diagnosed with head and neck cancers, the tissue taken from tumors was HPV positive and HPV 16 was present in 90% of these positive HPV tissues. This information helps to confirm that there is a strong link between HPV 16 and oral cancer.
What is meant by "combine tobacco and alcohol with HPV"? It sounds like they might physically serve in some manner to enable HPV to enter epithelial cells, with nicotine holding the cells open while the alcohol washes it in or something.
But most likely it doesn’t mean that at all. It probably simply means that people with a history of oral sex are quite likely to also have a history of smoking and drinking. Let me guess: I bet that they’re quite likely to have a history of listening to loud rock music. dancing, and dressing fashionably smartly. That is they’ll have histories of doing all the things that people do when they go and try to get themselves laid. They get a bit drunk to lose their inhibitions, and they smoke cigarettes to calm their nerves, and then they hope they’ll, well,.. get lucky.
And what counts as oral sex? Is it just oral-genital sex, or does that include mouth-to-mouth snogging? It probably does include the latter, because anything that transfers tissue from mouth to mouth is likely to tranfser HPV from one mouth to another. But so also is sharing someone’s food or cup or fork. There can be all sorts of ways that a virus can be transferred from one person to another. The less material that is transferred, the less likely someone is to get infected.
And in the same token, if all those people smoking and drinking out on the dance floor in a club at night are more likely to get laid and infect each other with HPV, it follows that non-smoking non-drinkers who stay at home at night reading books are less likely to get laid, and contract an HPV infection.
Second link from WebMD relates to throat cancer:
Having multiple oral sex partners topped the list of practices associated with an increased risk of developing oropharyngeal cancer, according to the study published in the May 10 issue of The New England Journal of Medicine.
People in the study who reported having a history of six or more oral sex partners were three times as likely to develop the cancer as people who reported that they had never had oral sex.
In looking at patients with tumors that were positive for a particular strain of HPV already well-linked to cervical cancer, six or more oral sex partners increased risk for throat cancer by eightfold.
And those who showed evidence of a prior oral infection with human papillomavirus (HPV) were 32 times more likely to develop the cancer.
Oral sex seemed to be the main mode of transmission for oral HPV, although the researchers note that transmission from mouth to mouth contact couldn’t be excluded. The new study shows that oral HPV infection is linked to head and neck cancer regardless of two other known risk factors: heavy tobacco and alcohol use.
What’s meant by "head and neck cancers"? A neck isn’t quite the same thing as a throat. It seems to be suggesting that cancers on the outside of the neck or head aren’t associated with tobacco and alcohol. Transfer of HPV from mouth to head or neck might not be sexual at all. They might be transferred by coughing or sneezing or a peck on the cheek. No ‘sex’ at all. And so no need for tobacco and alcohol, those two great sexual enablers.
Epithelial cells, which cover the entire surface of the body, inside and outside , are also found in lungs:
So if HPV 16 and 18 targets epithelial cells, it will most likely target epithelial cells in the lung as well. As I’ve reported before, HPV has been found in 25% of lung cancer cases, and sometimes (in Japan) in as many as 80% of cases.
If HPV is the true cause of many cancers, including lung cancer, then why was there such an upsurge in cancer in the 20th century? And the answer may be that it had nothing to directly do with smoking, but had everything to do with relaxing sexual mores, which may have paradoxically come as a response to improving medical treatments of the more common sexually transmitted diseases – like syphilis and gonorrhea – and also, equally importantly, improving contraception. Once people were having multiple sexual partners and engaging in experimental sex, HPV started jumping from person to person. But why was it lung cancer so often? Perhaps because the surface area of human lungs is very large:
The external surface area of a human is about 2 or 3 square metres.This suggests an airborne HPV transmission route person to person. An airborne stray packet of HPV may have a good probability of ending up in human lungs. But how? Maybe it was because back then people danced cheek-to-cheek on crowded dance floors, changing partners every few dances. While they danced, cheek to cheek, and very often nose by nose, they breathed in airborne HPV. If so, then the reason that lung cancer incidence peaked in the late 20th century (if it has peaked) is because by then people danced separately after dances like the jive and the twist became fashionable. It could be that Chubby Checker single-handedly did far more to cut the incidence of lung cancer than all the doctors in the world laid end to end.
And that the waltz was the dance of death.
POSTSCRIPT: If lung cancer is the consequence, 10 or more years later, of HPV infection, why was there an asymmetry in its incidence between men and women, with women getting it a lot less often? One way this might have happened would have been if lots of men had sex with relatively few women – e.g. prostitutes or ‘loose women’. If there was an asymmetry between men and women’s sexual practices – i.e. a ‘double standard’ – with fewer women becoming sexually liberated, then fewer women would have been infected. And there was indeed a double standard. But as women also became more sexually liberated, HPV would have spread from the red light districts to the wider community, and an epidemic of lung cancer started. If so, to specifically cause lung cancer, it suggests that HPV must have ‘taken off’ and become airborne at some point, perhaps concentrated in a very localised HPV-rich ‘hot spots’, like clubs and bars.