And another thing, I know it's not as common for guys to go down on women, but almost every woman i've known has done oral sex on guys... so, why is oral cancer much more common in men than women? I mean, it's six times as common in men than women. If the oral sex is the culprit in transmitting HPV, how does it explain this discrepancy?

Okay, let's assume even distribution in a mathematical sense. For example, it's impossible for guys to have more female sex partners on average than girls having less male sex partners on average. This, mathematically, could never happen... but it was reported so in the daily newswires--meaning men and women lie about their #'s. So, let's assume men and women equally have oral sex. Then, they would equally have the same distribution of oral HPV infections. So, why do men have higher rates of these cancers? It might be due to smoking, but I don't have the historical data on that since that would require the smoker distribution 30 years ago.