One of the most stressful conversations for our patients surrounds abnormal pap smears. Hopefully this information will help to reduce stress and provide helpful information. Starting with basics, a pap smear is a screening test for cervical cancer and generally can pick up changes in the cervix way before cervical cancer even develops. For these reasons cervical cancer is exceedingly rare in patients being followed at CWCC. In fact since 2002 when we began, CWCC has never had a case of invasive cervical cancer in a patient that we are following. We certainly frequently pick up pre-cancerous changes, which may or may not ever become cancer without treatment, and treat them. Keeping it in perspective, pre-cancerous changes can’t hurt you, and the whole point of pap smears is to prevent cancer by picking up these changes early.
When we have a pap smear, we check for two things. One is the appearance of the cells which are retrieved with the cervical swab, to see if they have any precancerous appearance. These changes, if present, are called “dysplasia” and are graded mild, moderate or severe. We also check for the presence of certain strains of the HPV (human papilloma virus) since HPV has been found to be the causative agent for cervical cancer. Patients who are negative for these HPV strains have an exceedingly low risk of cervical cancer and do not require frequent evaluation. Patients with dysplasia invariably carry the HPV virus (since HPV is what causes dysplasia). The pap tests for certain strains of HPV that can be associated with cervical cancer. It does not test for all strains of HPV. For example if a patient has genital warts which are caused by HPV types 6 and 11, they will test “HPV negative” on a pap smear since types 6 and 11 are not in the pap smear panel, because they don’t cause cervical cancer. The types of HPV tested for with a pap smear have unfortunately been named “high risk HPV”. Naturally when a patient is told that she has “high risk HPV” it sounds scary. Really they should be called “some risk HPV”. If we carry one of these strains we have some risk of developing cervical cancer if not treated, compared to essentially zero risk if we don’t carry one of those strains. Only a very small fraction of patients who carry a “high risk HPV” go on to develop cervical cancer, and those few were generally not being followed closely by a doctor.
When we diagnose dysplasia on a pap, the next step will be to do a procedure called colposcopy. A colposcope is a magnifying lens on a stand that allows us to look at the cervix with magnification and see areas of dysplasia that are not visible to the naked eye. If we see abnormal areas we take a small biopsy to confirm that the pap smear was correct. Sometimes what appears on the surface (sampled by the pap smear) is different under the surface, and the biopsy is the gold standard to decide if treatment is needed. In most cases the biopsy matches the pap smear, but not always. During the colposcopy we can also collect a sample from the cervical canal which is not visible, to make sure that there are no precancerous changes hiding up out of view. The results of the colposcopic biopsies are described as normal, or level 1, 2 or 3 precancerous changes. In general we will treat level 2 or 3 changes and often will offer observation to patients with level 1 changes. The reason not to treat immediately is that the HPV virus can go away, and in most cases our immune system clears it over time. So if a patient has mild (level 1) changes we don’t have to treat it right away, and it is safe to observe and repeat the pap every 4-6 months for a year or two to see if it resolves on its own.
If treatment is recommended there are two main types of treatment that may be offered. The first is called cryotherapy and uses liquid nitrogen to freeze the outer layer of the cervix and destroy the abnormal cells. This would be appropriate for level 1-2 changes which do not involve the cervical canal (since the freezing is only on the outside of the cervix and can’t treat the canal). The upside is that this is a quick (less than 10 minutes) procedure done in the office without anesthesia and has a high success rate. The downside is that is causes an unpleasant discharge for 2-3 weeks and we do not have a specimen to confirm that we destroyed all the bad cells. The second choice is a LEEP (loop electrocautery excision procedure), which is done in an outpatient surgery center under anesthesia and actually cuts a circular portion of the cervix off, encompassing all the visibly abnormal areas, and the specimen is then sent to the pathologist to confirm that we have clear margins. This would be appropriate for a patient with a higher grade problem or with abnormal cells in the cervical canal. The downside of a LEEP is that is can potentially be damaging to the cervix and is associated with higher pre-term delivery rates.
It is extremely unlikely that you will develop cervical cancer if you follow your doctor’s recommendations for follow-up, and we encourage you not to worry if you have been diagnosed with an abnormal pap. Just remember that precancerous cells can’t hurt you, and diagnosing them at this stage is a blessing.
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