Please debunk this (homosexuality and colon cancer)

I was flipping through the radio dial last night, and there seems to be a new talk show on one of my favorite FM channels for some reason. Some local idiot blathering on about ultra (and I mean ultra) conservative ideas. One of which was the fact that 50% of ALL male homosexuals have colon cancer.

50%.

He has to have that number wrong, doesn’t he? I suspect that it’s possible that homosexuals have a 50% higher chance of getting colon cancer (i.e. if the current rate for all males is 4%, the rate for gay males would be 6% - 50% more than 4%).

Thankfully I arrived home before my head exploded listening to him. He never did provide a cite for his information, which I doubt he would be able to do upon request.

Well, according to WebMD, sexual behavior (or orientation) has nothing to do with the risk factors of developing colon cancer:

Moreover, it lists who is at risk for colon cancer, and again, homosexuals aren’t there:

Looks like the guy on the radio was talking out of his ass (ha ha).

I know where he got it, though. There are some studies that link anal sex with anal cancer, and to a Conservative with an anti-gay agenda, “colon” might as well be “anus”, and the facts that not all male homosexuals practice anal sex, and that women practice anal sex, too, would go right over his head.

http://content.nejm.org/cgi/content/abstract/317/16/973

http://content.nejm.org/cgi/content/short/337/19/1350

<i>… to a Conservative with an anti-gay agenda, “colon” might as well be “anus” …</i>

So what you’re saying is he doesn’t know his ass from his elbow. Er, colon.

From what the studies say, it looks like the real culprit is our old friend the human papilloma virus, which also causes warts and cervical cancer and the like, right? So it’s not anal sex per se that is an increased risk factor – you have to be having sex with an HPV-infected individual? In which case, it’s just another reason why unprotected sex with multiple partners is a bad idea?