[Question #627] HPV Questions

102 months ago

Doctors, thanks for your help with my prior questions about HPV. I was hoping you would be willing to answer a few more questions:

I understand that an estimated ~80%-90% of all people will have at least one genital HPV infection during their lifetime. Of those who will have at least one genital HPV infection, do you have a sense of what percentage will have a high-risk (i.e., potentially cancer causing) strain?
I am aware of a study examining HPV transmission rates, which (according to my untrained layman's reading) found that when one partner in a couple had an HPV infection the transmission rate to the other partner was ~20% over a 6-month period (per the study, couples in ongoing partnerships reported a median of 4 vaginal sex encounters per week and 50% never used condoms). Is that 20% figure consistent with other studies of which you are aware examining HPV transmission rates? (Link to referenced study: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3203235/)
My understanding is that for women 30 and older, one option under the current cervical cancer screening guidelines is screening with both the HPV test and PAP smear every five years (assuming both are negative at the prior screening). Is it possible for HPV to progress from an initial infection to cancer within the 5-year window between co-screening with the HPV test and PAP smear? Would the fact that a woman went through one or two pregnancies in the 5-year period between screenings make such rapid progression from infection to cancer more likely?

Thank you.

H. Hunter Handsfield, MD

102 months ago

Welcome back to the forum. However, I would point out that each question can have up to three replies, i.e. to the original question plus two follow-ups. This could have been a follow-up in your last thread (this is your third).

Your current questions, and perhaps your previous ones, suggest you are more concerned about genital HPV than most people or than necessary. The bottom line is that the large majority of infected people (90% of the population) never have any recognized health problem from HPV; and the proportion who have a serious or life threatening one (cancer) is extremely small. HPV is not something that most people should be concerned about at all. But enough of the "lecture"; to your questions.

1) High risk HPV types are the most common. As rough approximation, probably half or more of all people experience one of more HR HPV infections during their sexually active years.

2) I was not aware of that specific study, but the investigators are highly respected and on quick scan it looks pretty good. On the other hand, other data show that 20% of university women acquire HPV their very first sex partner, often after only a few exposures. By 3 lfie partners, 50% have been infected -- and here too, most probably were infected within the first several exposures. In another study by the latter investigators, the rate of new HPV in non-condom using university women was 89 per 100 person years -- that is, over a year of exposure, 89 of 100 women would acquire HPV, and this doesn't even take partners' HPV status into account. These varied results imply that HPV transmission frequency must vary widely over circumstances not well studied, from lower rates like those in the study you cited to higher rates in others.

3) Is it possible for HPV to progress to cancer between test intervals in the circumstance you cite? I'm sure it is. But it's very uncommon, and policies like that are highly protective. We don't demand perfection from any safety device or strategy. People die in car wrecks and house fires despite seat belts and smoke detectors. And of cervical cancer despite careful adherence to testing guidelines. In any case, I am not aware that pregnancy alters the risk, i.e. I see no reason to worry that whichver woman you are speaking of (a partner of yours) being pregnant twice between 5 year screenings would be at any increased risk.

Going back to my earlier point: Someday your partner is going to succumb to something. The chance that it will be from HPV, if she follows standard recommendations, is extremely small, especially in comparison with all the other things that can go wrong, like breast or colon cancer, heart disease, or an accident. I really see no reason or need to be focused on HPV, even if you or she have previously had documented high risk HPV infection(s).

I hope this has helped. Best wishes-- HHH, MD

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102 months ago

Doctor, thank you very much for your replies to my specific questions as well as your overarching comments. Both are very helpful and much appreciated. I realize I have become more fixated on HPV than is necessary or healthy. The guidance and information I have received on this site have greatly helped me work through that issue, and I think I will be able to move on thanks to the help you and Dr. Hook have provided. Thank you both for providing this great service!

H. Hunter Handsfield, MD

102 months ago

Thanks for these comments. Glad to hear this discussion might have helped your perspective. An additional fact in point no. 1 above is that "high risk" doesn't mean inevitable cancer -- and semanticly "highER risk" is more accurate. Just as most smokers don't get lung cancer, the large majority of HR HPV infections don't go on to cancer, even if never detected or treated.

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