A simple google search inquiring about the yearly pap smear will produce thousands of results. Many top news sources have headlines such as “Say Goodbye to the Yearly Pap Smear” and “Less Frequent Pap Screening Recommended”, yet at my office, I still highly recommend the annual pap smear.
Experts, including those from the American Cancer Society, created new guidelines in 2012 that recommend waiting as many as five years between pap smears. Though these guidelines tote scientific evidence behind their claims, if you were to look closer into these studies, you’d see that they compare their five year pap to the three year pap rather than comparing it to the previous gold standard, the one year pap. This week, our blog will discuss why at my office, I recommend an annual pap, why the recommendations are for much longer, and in what instances pap smears should be conducted more or less frequently.
The primary reason for a pap smear is to detect precancerous changes to the cervix. It is now known that the virus, HPV, is the primary cause of these cellular changes to the cervix. Since the pap smear was invented in the 1940s, women have been getting pap smears once a year. This caused a 70% decline in cervical cancers, currently making cervical cancer a rare and preventable cancer. Pap smear recommendations have only changed in the last three years, but studies are showing that there is an increased cervical cancer risk associated with screening every 5 years.
Here's a passage from a study that investigated the effect of screening at longer intervals:
"Extending the cotesting screening interval from 3 to 5 years at ages 30-64 years will result in an additional 1 women in 369 compliant with screening receiving a cervical cancer diagnosis during her lifetime, and an additional 1 in 1,639 dying of cervical cancer.
The authors believe that a significant number of patients and providers would not choose to accept these additional risks if they understood them, despite the recognition of potential harms associated with more intensive screening."
-Kinner, W.M.D. et al. (2015)
Another issue many of these experts do not discuss is the ability of the pap smear to detect additional problems, like endometrial cancer and infections like yeast, gardnerella, trichomonas, and more.
Endometrial cancer is cancer of the uterine lining and it is a cancer that can be hard to detect since the inside of the uterus is not routinely examined. When a woman has endometrial cancer, cancerous cells can begin to work their way out of the uterus through the cervix. This is where the pap smear comes in. This year alone, I detected two endometrial cancers with the pap smear, a test that is not even designed to look for endometrial cancers but can still find them. This would be like going for a chest x-ray to screen for tuberculosis and finding out you have a dislocated rib. You got the X-ray to make sure you did not have tuberculosis but what you found out was that you had another problem all along.
"This year alone, I detected two endometrial cancers with the pap smear, a test that is not even designed to look for endometrial cancers but can still find them."
A pap smear is a screening tool for cervical cancer -- though it may also detect other problems it was not designed to like endometrial cancer, yeast infections, bacterial infections, and more. During a pelvic exam, a doctor takes a swab of your cervix (the entrance to the uterus) to pick up a samples of its cells. The cells are then looked under a microscope to check for any abnormalities or changes.
The pap smear is one of the most successful cancer screening tools in history because of its drastic reduction in cervical cancer.
Pap smear results:
So the question is, when do you get a pap smear? First, we'll divide paps into section by age, then we'll be more specific about the time recommendations.
Not only is 21 the age that young adults can legally consume alcohol, but it's also the age that regular pap smear screenings begin.
Even though young women should begin to see their gynecologist at age 18 or when sexual activity begins, pap smears are not done until age 21. This because abnormal cervical changes do not show up immediately and many results will be insignificant. Additionally, HPV is only tested if a pap smear result is abnormal. This is because HPV infections are most common when women are in their 20s, and oftentimes, the immune system is able to fight off a mild infection on its own.
What they say vs what I say:
The American Cancer Society (ACS) guidelines state that women in this age group can wait as many as three years between pap smears, however I do not personally believe in this recommendation. As stated above, HPV infections most commonly occur when a woman is in her 20s and though it may clear on its own, there are over 100 different strains of the virus, 15 of which put you at a great risk of developing cervical cancer.
At age 30, cotesting begins. When your pap is sent to the lab, they will also check for HPV along with the cell shapes. This is because an HPV infection, even along with a pap smear, is more likely in this age group to become problematic.
The longer you are infected with HPV without clearing it, the more your risk for dangerous cervical changes increases.
What they say vs what I say:
The ACS guidelines actually state that if you are co-testing with HPV and you are consistently HPV negative with normal pap results, you can wait as many as five years between your pap smears. They also recommend that if you decided against co-testing, that annual paps should be conducted.
I've mentioned above that I do not recommend going more than 1 year without a pap due to the ability of the pap smears to detect other abnormalities in addition to cervical changes. Additionally, without the necessity of the pap smear, some women will decide to forego a checkup completely. If this occurs, she is missing out on breast exams, mammogram orders, rectal exams, colonoscopy reminders, and the general pelvic examination.
At age 65, things change a little. Many women at this time switch over to Medicare for their health insurance. Before this, insurance would cover a yearly pap smear -- yes, even despite what the ACS guidelines are -- but Medicare will only cover a pap smear every other year. That said, many women still opt for the yearly pap screening to keep on top of their health. Some women in this age group are still required to do annual paps.
How often to pap smear for women 65 and older:
Every Two Years without cotesting
Every Year with cotesting
What they say vs what I say:
Some guidelines state that if a woman has never had an HPV infection AND never had an abnormal pap smear, she does not need to have pap smears anymore. Again, I recommend against this because of the possibility of missing endometrial cancer and other infections and also because of the likelihood of women missing out on all the preventative health benefits of a full exam (breast, rectal, pelvic, etc.).
I want to preface this section by restating that I consider the annual pap smear to be the gold standard for women's preventative health screening.
The 2012 guidelines were written based on the average woman's ability to clear herself of an HPV infection and an abnormal pap result within two years. But what about those who may fall below average? What about those who are at a greater risk due to diet, lifestyle, body composition, and other factors? What are we giving up by lengthening the time between screenings?
It IS true. It is. It's true that the majority of women will not develop cervical cancer and that if cancerous changes begin, they may be detected on a three or five year interval. However, as mentioned above, there is an increased risk for cervical cancer, especially at the five year screening interval. To me that is concerning. If you have an abnormal pap smear, depending on the severity of the abnormality, your treatment may even begin immediately. Three years down the line, the severity of your treatment may need to increase in order to eradicate any dangerous cellular changes.
So this is my recommendation as a medical doctor in advanced gynecology for over 20 years: get a yearly pap smear. It continues to be covered by insurance, regardless of the guidelines, so why not?
Who: Ages 21 and above (unless covered by Medicare)
If you have an abnormal pap smear, it is necessary at that point for you to be switched to a temporary 6 month surveillance plan. Abnormal pap smear results require different treatments depending on the results, however what remains consistent is the need for pap smears every 6 months. Once a woman is able to go 2 full years without an abnormal pap, she can return to her normal, annual routine.
Who: Women with abnormal paps who have not gone 2 years with a normal pap result
The primary reason for a 2 year pap smear to be conducted is for women who are covered by Medicare and cannot afford a pap smear without health insurance coverage. Only women who are 65 and older and who do not have a history of HPV infection or abnormal pap smear results are a candidate for 2 year pap smears. Women with more than 5 sexual partners in their life, regardless of HPV or pap results should get yearly pap smears instead.
Who: Ages 65 and above on Medicare coverage
The three year pap is a new recommendation made by the ACS in 2012.
Their reasoning is that it is safe to wait three years between pap smears since they believe the annual pap smear only serves a small benefit over the three year pap smear. They also speculate that it will decrease the number of false positive results. A false positive result is when a pap smear result indicates an abnormal change even though there is not actually an abnormal change.
This guideline was developed solely on evidence accounting for cervical cancer and HPV statistics that were only associated for a slight increase in risk. These guidelines did not take into account the ability for the pap smear to detect endometrial cancer and infections by Yeast, Trichomonas, Gardnerella, Herpes, or Actinomyces.
If cervical changes and HPV infections were the only things able to be detected by a pap smear, I might be more in favor of the three year guideline, however, this evidence was not enough for me to disregard my practice in protecting women's health.
"These guidelines did not take into account the ability for the pap smear to detect endometrial cancer and infections by Yeast, Trichomonas, Gardnerella, Herpes, or Actinomyces."
Who: (based on the ACS, not my recommendation): Ages 21-29, okay for ages 30-64
The 5 year pap is another recommendation by the ACS made in 2012.
This guideline compares the five year screening with the three year screening the results from these studies are even farther separated from the annual gold standard. The five year pap smear doubles the risk of cervical cancer, even with a negative HPV result.
Like the three year pap, I do not recommend it.
Who (based on the ACS, not my recommendation): Ages 30 - 64 who consistently have HPV negative, normal paps
So, given all of this information, what can we glean about the reason for these new guidelines at a changing time in health care?
To put it simply, it saves money. It decreases the amount of money spent on pap smears annually by three times, assuming doctors follow the guidelines.
But, here's another fact, 86% of doctors do not recommend the three year pap smear! That's the vast majority of physicians. And I can tell you that it's not these physicians that instated the new 2012 guidelines in the first place.
Because insurance continues to cover the annual pap, I find no reason to discontinue them.
They are a screening measure that was developed with the protection of women in mind. The current extended recommendations are basing their reasons solely on the detection of cervical cancer and HPV infection. Though the guidelines state that the lengthier screening intervals are similar to the annual for protection and may decrease false positives, studies have shown that there is an increased cervical cancer risk when screening at a five year interval. If pap smears were done every five years instead of every year, 200,000 cases of cervical cancer would be missed. In fact, the majority of women who come to a gynecologic office who are then diagnosed with cervical cancer have not had a pap smear in over five years.
Though cervical cancer screening is the primary reason for a pap smear, it can also detect endometrial cancer and other infections. The importance of the pap smear is to preserve your health. Additionally some women will decide to skip a checkup completely without the requirement of an annual pap smear. This causes her to miss out on breast exams, mammogram orders, rectal exams, colonoscopy reminders, and the general pelvic examination.
"If pap smears were done every five years instead of every year, 200,000 cases of cervical cancer would be missed."
I want to stress that endometrial cancer and cervical cancer are still rare and your chances of getting them are 1 in 37 and 3 in 5,000 respectively. Furthermore, the precancerous changes detected on an abnormal pap are also likely to clear on their own. The majority of abnormal pap results resolve within 2 years and are unlikely to progress to cancer, especially with screening. HPV, the primary cause of cervical cancer can also clear itself on its own, usually within two years. Persistent HPV infections, that is a positive HPV result is more likely to become cancerous. 5-10% of persistent HPV progress to cancer without further intervention.