[Question #3505] Anal warts and cancer risk/screening

36 months ago
Hello Dr HH,

       Greetings from Australia

       I am a 40 year old bisexual male currently in a heterosexual relationship. Last week I was diagnosed with about half a dozen perianal warts by my family doctor who treated it with nitrogen. With regards to my sexual history I have had anal sex in the past , mostly as a ‘bottom’ but only once in the past 4 years (10 months ago where I was a ‘top’). I had 2 HIV test last year, which were negative. I have never ever had unprotected anal sex in my life.

      My main concern is my risk of cancer, particularly anal but also of the throat. Whilst I understand that the HPV that causes anal warts don’t cause cancer, people with my sexual history would have been exposed to other types of HPV, including the more notorious types and my risk of anal cancer is about 20 times of a heterosexual person.

      I am obviously quite concern about this and asked about screening but my family doctor didn’t seem to think it’s required.  Doing my own reading there seem to be talk of a rectal exam, proctoscope, anoscope or anal Pap ( the last 2 apparently not readily available ).

    What would your advice be for someone in my situation?  What sort of screening do I need at my age, if I need any. 

    Many thanks
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
36 months ago
Welcome back to the forum. Thank you for your continuing confidence in our services.

Your anal warts probably are unrelated to your sexual orientation, i.e. that you have male as well as female partners. Anal warts are not rare in strictly heteroseuxal men with no sexual exposures of their rectums. The exact origins are not understood, but are believed to involve auto-inoculation (self-infection, e.g. after contact with one's own genital HPV followed by anal finger contact in toilet, etc); by partners' manual contact; or, the one I mostly favor, the migration of genital area HPV infection over the relatively short distance between genitals and anus.

Genital and anal warts are caused by different HPV types, as you know, and even among men with anal warts, heterosexuals (as which you qualify, from an anal health standpoint) do not have an elevated risk of anal cancer, to my knowledge. (That said, I doubt this has been carefully studied.) As for throat cancer due to HPV, it's due to a single HPV type (HPV16), which doesn't cause warts. HPV16-caused throat cancer is a risk, but a low one, for all sexually active people, and is no more frequent as far as we know in men with and without genital or anal warts. Finally, I disagree that your anal warts means you have been exposed to multiple other strains. The higher risk in MSM comes from multiple episodes, with multiple partners, of unprotected receptive anal sex, a history you don't have.

As for screening, oral/throat HPV screening is not recommended by any significant health authority, even though you can find promotions for such testing by online labs and such. Having (or not having) HPV16 in the oral cavity, or any other type of HPV, doesn't lead to any kind of testing or treatment that can lower the risk of cancer. And in any case, while neither throat nor anal cancer are so rare that they should be ignored, they remain far less common than other well known cancers like colon, rectum (not the same as anal), prostate, breast, lung, etc. There's a good chance some form of cancer will someday be the health insult that takes you from this world, because cancer causes something around 40% of all deaths in industrialized countries. But the chance it will be HPV related is miniscule.

So I would recommend close follow-up of your anal warts, including probably internal examination (e.g. anoscopy) by an expert (proctologist, colon & rectal surgeon, etc), but no other interventions at this time.

You also could consider being seen at your nearest governement supported sexual health centre. Australia's SHCs collectively are the world's top STD/HIV prevention and carte clinics. All are excellent, but if you happen to be in or near Sydney or Melbourne, you have access to the best of the best. You wouldn't go wrong with their assessment of your situation.

I hope this information is helpful. Let me know if anything isn't clear.

HHH, MD
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H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
36 months ago
FYI, there's a typo above:  "Genital and anal warts AND CANCER are caused by different HPV types...." i.e. the same types cause both anal and genital infections, but the types that cause warts rarely cause cancer, and vice versa.---
36 months ago
Thanks for your reply

So my risk of anal cancer is closer to the one of a heterosexual male rather than the one of a HIV negative MSM  because I have always used protection ? That’s very reassuring. However, one statement that’s always cropped up during my reading is that ‘condoms do not offer full protection against HPV’ (thought I’m not sure how it can’t ). If that is true, would I not have an increased risk ?

Have a happy Easter 
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
36 months ago
Looking at your original question, I misunderstood that you had a past history of (frequent?) receptive anal sex (bottom), exclusively with condoms. My apology. It means I cannot judge whether your anal warts were directly sexually acquired, due to undetected condom failure or through other mechanisms we don't necessarily understand. I would guess that, as you say, your risk for anal cancer is a lot lower than for most men who have sex with men, with multiple unprotected anal sex exposure by multiple partners. However, I cannot say the risk is as low as for most straight men.

In any case, close follow-up by a knowedgeable physician will fully protect you from cancer, at least at a harmful level. The conservative approach probably would be for you to follow the care that most experts would offer to MSM at higher risk. This probably will include careful examinations to detect early growths of either warts or pre-cancerous lesions, low threshold for biopsy if something shows up. With ths sort of care, the chance of actual cancer should be zero or close to it. My comments about getting seen at a SHC remain valid:  some of them probably provide exactly this sort of care, and all probably would be able to suggest other excellet sources.

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