the pap smear

    In this post, I want to go into depth about the pap smear.  What is it?  What is it designed to look for?  Who needs it and how often?  What comes after an abnormal pap?  And what is HPV and its association with cervical cancer.
    There is a lot of misunderstanding about the pap smear leading to a lot of confusion among both patients and physicians.  Further, a recent study showed that only about 40-60% of gynecologists are following nationally recognized pap smear guidelines, which to me is very frustrating as it leads to confusion when patients come to see me for an abnormal pap.
    Pap smears are a SCREENING test for precancer cells of the cervix. 
    In the picture on the top right, you can see the cervix, uterus, tubes, and ovaries.  The picture in the middle shows the process of doing a pap.  A speculum is placed into the vagina so that the cervix can be visualized.  Then cells from the cervix are obtained with a brush and spatula and sent to a pathologist for review.  They review the slides and then send a report stating whether they look normal or abnormal.  There are several different levels of abnormal, and depending on the abnormality, different follow-up is needed.
    The key thing here is that the pap smear is just a screening test.  It does not tell anyone that there is precancer and it does not localize the problem.  The cells are just random scrapings from the cervix.  Many women will have an abnormal pap smear during their lives, but the majority will never develop cancer.
    Who needs a Pap?  Pap smear recommendations have changed immensely over the past two decades, as we have learned more about the development of cervical cancer.  The pap smear by itself is not a good test.  It has a very high false negative rate, meaning that the test comes back negative but there is a problem.  The only reason that the Pap Smear ever worked is because it takes 10-20 years for cervical cancer to develop.  Within that time one of the Paps would be positive, and the woman would be further evaluated.  Because of the high false negative rate, Paps were done yearly, and this has been hammered into women’s heads for decades. 
    We now know that almost all cervical cancer is caused by a virus, HPV.  Every woman that has ever had sex, has been exposed to HPV.  There are hundreds of different types, and we give them different numbers.  Think of them as cousins.  Most cause no problems at all.  Some, that we refer to as low risk, can cause warts.  Some, that we call high risk, have the potential to cause cervical cancer.  Potential is the key word as most woman that have high risk HPV will clear the virus and never get cervical cancer. 
    Woman that are younger are more likely to be exposed and get high risk HPV.  They tend to have more sexual partners and their cervix acts differently than a woman in her 50’s.  Because of this, the recommendations for Pap Smears are based on age. 
    Paps should start at 21 and be done every three years, assuming they are normal.  We don’t automatically check for HPV in this population.  Starting at age 30 and going to 65, it is recommended to check a Pap and HPV test every 5 years.  The chance to go from a normal pap and normal HPV to precancer in 5 years is 0.18%.  By adding the HPV to the Pap Smear, we significantly increased its predictive ability for precancer.  It is sometimes difficult for patients to understand why doing a Pap smear and HPV every five years is better than a yearly Pap.  Remember the Pap by itself is not a great test.  Think of cervical cancer like colon cancer.  We don’t get colonoscopies every year because it takes decades for colon cancer to develop.  The same applies to cervical cancer.  After the age of 65, we stop pap smears altogether.  If a woman has not developed precancer of the cervix by 65, she is not going to get cervical cancer. 
    What happens when your Pap comes back abnormal?  First, don’t panic as most women have no issues.  The next step depends on the abnormality.  An organization called the ASCCP (www.asccp.org) meets regularly and develops the Pap recommendations based on research and data.  If your doctor calls and sets you up for a colposcopy, don’t panic.  It looks worse than it is. 
    A colposcopy is designed as a diagnostic test as compared to the Pap as a screening test.  The Pap showed us something MIGHT be abnormal, and the colposcopy will show us if there IS an abnormality. 
    The bottom picture at the right is of a new modern colposcope.  In my office, we now offer this state-of-the-art machine.  The process involves putting a speculum into the vagina so we can see the cervix.  We then put vinegar on the cervix.  Abnormal cervical cells will soak up the vinegar differently than normal ones causing the abnormal area of the cervix to appear different.  The colposcope allows us to use a camera to visualize the cervix close-up, looking for patterns that may indicate precancer.  The above machine also uses computer artificial intelligence to help determine where the problem may be.  Once we see an area of concern, a biopsy is done and that will tell us what the abnormality is.  Once we know what the abnormality is, treatment can be suggested.  In a modern first world country, no one should get cervical cancer.  If you follow the guidelines, get you Paps, and complete your colposcopy, you should never get cervical cancer. 
    I hope this helps you understand what a Pap Smear is, why we do them, and how abnormal Paps are managed.  If you have not had you pap smear or feel you want to know more, please make an appointment to get you up to date.  

ASCCP Pap Smear Guidelines

DYSIS Colposcopy