Monday, April 16, 2012

MEDICINE : Hurrah for Pap Smears!


You just turned 21? Congratulations!
Now go to the Tang Center and get your first Pap smear!

A Pap smear is a screening test for cervical cancer, a cancer that affects nearly 500,000 women worldwide each year.  270,000 women in the world die of this cancer each year.  But in nations with effective screening programs, the incidence and mortality from this disease has dropped dramatically. In the United States, the mortality rate from this cancer has plumetted 70% over the last 60 years (in 2012, 4000 deaths are predicted) thanks to effective screening by the Pap smear.

The Pap smear catches very early abnormalities in cervical epithelial cells that are usually harmless and will usually not progress to cancer.  Rarely, these abnormalities sometimes become precancerous and some even will develop into cervical cancer.  The important thing is that the Pap smear will detect abnormal changes very early on, well before any danger of cancer.  Reassuringly, most of these changes will go away spontaneously without any treatment.

The Pap smear is a simple test. It can be done by a nurse or MD and involves a pelvic exam. After a speculum is placed in the vagina, a brush collects a small sample of cervical cells that are sent for analysis. The sensitivity (the percent of true positives in those screened) of the test isn’t great, around 60%, but the slow progression  from the atypical cells found on Pap smears to invasive cervical cancer is very, very slow, over decades, in fact. This is the reason why the Pap smear is recommended every 2 years:   although the sensitivity of a single test isn’t remarkable, the chance of detecting an abnormality with repeated tests becomes extremely high. Many of the abnormal early cell changes are in fact ultimately innocuous and regress to normal spontaneously.  

The American College of Obstetricians and Gynecologists recommends that most women should get their first Pap smear at age 21 and then every 2 years until 30 (women who are immunocompromised need more careful screening) .  Women over 30 with 3 consecutive normal tests can be screened every 3 years. Why not more often?  Remember that the time from the detection of early abnormalities to cancer takes many years and that most abnormal Pap smears will become normal over time.  It’s better to wait and watch, assuming that good follow up care is available, so a lot of unnecessary procedures won’t be done while still ensuring effective screening. 

The Human Papilloma Virus (HPV) causes virtually all of cervical cancer and a very effective vaccination for women is available (check out my earlier article on this). If you are a woman from ages 11-26, you need to get the vaccination. The vaccine will protect women against the 4 HPV species that cause around 70% of cervical cancers. This means that even if you’ve been effectively vaccinated, there is still a risk of an infection that could ultimately lead to cervical cancer.  So even if you’ve had the vaccine, you will still need a Pap smear every 2 years. 

What can you do?
-get the HPV vaccination
-if you are 21 and older, get a Pap smear every 2 years
-use a condom during sex
-don’t smoke (increases chances of cervical cancer)
-pass this information to your friends and family

One last thing.  This effective screening program requires an exam every 2 years to work. The Pap smear isn’t free and a lot of uninsured women rely on Planned Parenthood for this life saving test. If federal government funding to Planned Parenthood is eliminated (as Mitt Romney vowed to do), then there will be a lot of women who won’t be able to get a Pap smear and could die tragically from cervical cancer because of this.  In 2004, before the Great Recession, there were 17,000,000 women in the US without insurance. 

The Doctor Behind the Medicine: 
Dr. Martin went to medical school at UCSF. He has now retired from his long and brilliant career as an anesthesiologist, now playing guitar and making bread on his spare time. Dr. Martin and three associates have started a delicious commercial wine, MC4. For those who are 21 and older, I advise you to check out MC4-- cheers!

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