Cervical Cancer and Birth Control PIlls

A recent meta-analysis has confirmed that use of birth control pills slightly increases the risk of cervical cancer. But before you stop your pills, take a deep breath, relax and read further.

Because the risk is really small. How small? Well, if you live in a developed country (meaning you have access to Pap smears), use of the pill for 10 years increases your chance of having cervical cancer from 3.8 per 1,000 to 4.5 per 1,000.

Remember that the real cause of cervical cancer is not birth control pills. It’s infection with the Human Papilloma Virus (HPV).

But estrogen metabolites of the pill may make your DNA more susceptible to changes induced by the HPV virus. The pill can also make the glands of the cervix more exposed to infection by the HPV virus. The other big factor may be that women taking the pill may use condoms less frequently, thus making them more likely to get HPV.

The good news is that once you stop the pill, the increased risk of cervical cancer goes away. That means that when you get older and don’t need birth control, you won’t be paying the price for your decision to use pills when you needed them to prevent pregnancy.

Bottom line – limiting your number of sexual partners and getting pap smears regularly are the most important things you can do to prevent cervical cancer. There is also a vaccine to prevent HPV, but remember that it only protects against 2 of the 12 subtypes of HPV that cause cervical cancer, so it’s not a panacea.

And remember, the pill cuts the risk of ovarian cancer, a protective effect that lasts up to 20 years after you stop the pill. It also reduces your risks of endometrial cancer. And keeps your menstrual cycles shorter, lighter and less painful. Not to mention it prevents pregnancy.

A Gynecologist’s Perspective

I’ve been a practicing gynecologist for 20 years now. In that time, I can remember only 1 case of cervical cancer in my private practice, in a woman age 60 who was completely cured with a hysterectomy. (The cancer was so small they could not find it in the hysterectomy specimen because I had removed it all with my office biopsy.)

I recall many more cases of cervical cancer from my residency, most during my oncology rotation, and all in women who had not had pap smears in years. I remember vividly the woman who presented to the ER bleeding from a large cancer on her cervix. She had not seen a doctor since giving birth to the last of her 7 children, who was now 25 years old. I don’t think she ever took birth control pills.

On the other hand, I’ve lost count of the number of unplanned pregnancies that have occurred among my patients, and the number of my patients who have had abortions for an unwanted pregnancy.

Given this experience, I see no reason for woman to stop taking the birth control pills because of concerns about cervical cancer.

I can think of only one situation where I might tell a woman to stop the pill for this reason. That is the rare patient with recurrent cervical dysplasia and persistent HPV infection that does not clear. I had one such patient, and I changed her to the progesterone-only pill. She is doing well.

20 Responses to Cervical Cancer and Birth Control PIlls

  1. Thanks for explaining so well. I really find the dot charts helpful for visualizing risk. (And here, wierdly apt, since they look like a several year supply of the pill all in one big package.)

    Does the level of risk get higher over time, or is it pretty stable? That is, if I’m on the pill for ten years, is there more risk than if I’m on for five?

  2. Thank you for putting the “light” where it should be
    “Bottom line – limiting your number of sexual partners and getting pap smears regularly are the most important things you can do to prevent cervical cancer.”

  3. When you said that the patient who switched to the progesterone-only pill is “doing well,” do you mean that she’s doing well adapting to that pill with no side effects, or that she’s doing well in terms of dysplasia and HPV? I’m curious because I’ve had two abnormal paps in four years, both of which were followed up with a colposcopy. The first didn’t even warrant a biopsy, the second did and showed a very mild dyspasia. I’ve had paps every six months since the first abnormal one, just to keep an eye on things. I’m 26, but I’ve been on the pill (Lo-Ovral, currently) for ~8 years. I’ve never done much reading about progesterone-only pills, but I will now!

    Your blog is informative and thought-provoking, as always. Thanks!

  4. Thanks for the comprehensive info. I am 38 and started taking a combo pill 9mo ago due to very long periods and mood swings. Am I at greater risk for developing cancer because of my age? I have had the same partner for 12 years. I did have HPV and cryo-surgery 15 years ago, with no abnormal paps since then.
    Thank you.

  5. Anonymous #1 –

    Anonymous-

    Why not ask for an HPV test now to see if you still have the virus?

    THen discuss with your doc what is best to do.

  6. Meg –

    If the abnormal paps occurred over 4 years, and you had more than one sexual partner in that time, you may had two different transient hpv infections. ( I see this a lot in my practice). If that is the case, I would be less concerned than if you had HPV the whole time. Talk to your doc if you have questions about what is best for you.

    What you call “mild dysplasia” or LGSIL is not true dysplasia, but HPV related changes.

    While progesterone only pills are effective and safe, they do have slightly lower efficacy than combination pills and higher rates of irregular bleeding, plus they are less forgiving if you miss a pill. We are just assuming they will be better for patients with longstanding HPV because they don’t have estrogen – it’s an assumption – no data yet to back that up. Be sure to talk with your doc to find out what is best for you.

    The patient I was speaking about had recurrent CIN3, or precancerous lesions of her cervix, and peristent HPV years after remaining in a long term monogamous realtionship. These are the women at highest risk for cervical cancer. But even such women, if they have paps regularly, will ultimately do fine. Because we are really good at finding and treating cervical dysplasia long before it becomes cancer.

  7. It would seem to me that the increased risk could be entirely explained by the propensity not to use condoms when you’re on the pill (hence increasing your risk of contracting HPV). I didn’t read the research paper – did they control for that? If they didn’t then this may be one of those “well duh” moments.

  8. Hmm. Sounds like my issue and your patient’s issue isn’t really the same thing–and I really appreciate you taking the time to elaborate on that a bit.

    It seems like typical evening news/local paper sorta coverage describes all cervical problems as having the same progression: abnormal pap=HPV=cancer. I of course know that’s not the case, and it’s nice to be able to gather info about all those potential in between problems. Thanks again!

  9. Hello, love your blog (as a provider and a foodie)!

    Am interested in your comments about the +/-‘s of cycling of OCs for 3 months on before a week off to allow a menstrual cycle to occur. There is an OC that is packaged like this of course, and many providers tell women how to do this with their usual OC. Is there any evidence of a “down side” to this method?

    Thanks! Laurie

  10. Laurie-

    Using pills to cycle less than monthly can have a lot of advantages for women with heavy or painful menses that don’t respond to monthly cycling, and for women with endometriosis. Sometimes it’s also helpful for women with migraines. Migraines are funny – pills can make them worse of better, but if they are menstrual migraines, eliminating the menses can help in some cases.)

    The downside can be irregular breakthrough bleeding, which is more frequent than when you cycle pills monthly. And some women just feel better cycling monthly.

    I think a lot of the push to less than monthly cycling pills is that most of the monthly pills are off patent or soon to come off patent. There is a fair amount of hype over thee idea that less than monthly cycling might lead to less breast cancer, based upon the hypothesis that we were not meant to be having all these periods because naturally we would be pregnant and breastfeeding, so let’s get ourselves back to our predestined state, which is fewer menses. It’s a less than tidy hypothesis, especially when none of what we are doing with pills is “natural”. Natural is pregnant.

    I use a lot of less than monthly cycling for women with gynecologic conditions, but don’t push it either way in most women and let them decide what they want. Most of the time that’s monthly cycling, and that’s fine with me.

  11. TBTAM,

    I love that you put the cancer rate into visual form. Would be great to see two more charts – 1.) the chart of HPV infection rates with strains of the virus that can lead to cancer per 1,000 patients in the USA, and 2.) The cancer incidence rate in nations where pap testing and intervention techniques like colposcopy are not readily available.

    I don’t want folks to be alarmed at all, but they should be aware that HPV is a real drag, and having the data may help others to make personal decisions about preventing it (as you point out…)

    I am also REALLY curious about how wide spread the impact of HPV is considering the nature of oral sex in today’s society. My personal opinion is that the next wave of cancers with cache will be oral cancers as a result of HPV. Should be interesting to watch unfold…without doubt, this will be the next indication that big pharma goes after. If they get it, the fear mongering will begin! All of which rolls up into great blog posts and debates!!!!! 🙂

  12. Schruggling –

    Will get to those charts soon – although can tell you that chart #2 will look very different that that for the US. The developing world is where our efforts towards cervical cacner prevention need to be focused.

    As for HPV and oral cancer, I’ve got a post coming up about that this weekend – it’s a hot potato topic, and one that will surely be a marketing win for Merck adn friends. Trying to find a way to present the data without hyping or frightening….

  13. I figured you might have the oral data/argument brewing, hence the segue…it’s all about the segue.

    You are a posting MACHINE!!! (I hear a parody song running through my head!)

  14. Thanks for the info Peggy.

    I’m 43 my wife is 35, and she was diagnosed with HPV (the cancer causing type) before we met, and had cryo.

    That was about 6 years ago, and the cryo + progesterone cleared things up, and she’s had a normal smear since then….. until now.

    Now, her smear has been reported as a minor abnormality – “nothing to worry about” so they say, and she has to have another test in 3 months.

    We haven’t had kids yet, and I’m a bit worried about it. I’ve another year of university to go before graduating – but should we change our plans and try for pregnancy now? is it already too late?

    Sorry for asking, but I was thinking that many people may be wondering the same thing.

  15. I'm one of those rare women in our society…51 and I've never used oral contraceptives.
    I'd love to know how many women fall into my category.
    At University most women just went onto the Pill at 18 or so.
    My periods were a complete non-issue and I'm very bad at taking pills…so it seemed like a bad idea and I was concerned about possible health risks and side effects.
    I've had zero gyn problems over the years.
    I read recently that women who don't take the Pill have an increased risk of ovarian cancer…seems we can't win whatever we do…
    PS we used the Billings Method (and condoms on fertile days) successfully for 30 years.

  16. My case is very rare, but I am 27 and just had cervical cancer. They were able to get out all of the cancer with 2 cone biopsies and a lymph node extraction but it was pretty scary. I am healthy, do not smoke, not over weight.. needless to say it was quite a shock.I had a bad pap smear in 2003 and it was positive with HPV. All they had to do was a colpo and after that I had clear paps. In April 2009 I went in for my yearly and they said that was clear also. I went back in Oct 2009 to switch birth control pills because I missed a few and was spotting. They did a pap just to be careful and it came back bad. From there I had a colpo, which came back high risk, then a cone biopsy which came back cancerous. I saw many doctors and they all agreed to do a tracheletomy or another cone biopsy with a lymph node extraction (because they thought it could be in the lymphatic system) Thankfully they only had to do anoter cone biopsy and lymph node extraction. A week later I got the results back and they were able to get all of the cancer out and there was no cancer anywhere else. It was a nightmare but its finally over.

    I do feel that the cancer formed because of HPV and birth control pills. I was on birth control pills for 10 years.

Leave a Reply