By Vandna Jerath, MD
To pap or not to pap . . . that is the question? Cervical cytology also known as the pap smear is the primary reason for a 50% decrease in the incidence of cervical cancer over the past 30 years. For years we as ob/gyn doctors have been taught to do pap tests early and often. Well, really to do them at least yearly or more often if the patient was high risk. We were also advised to do them within three years of our adolescent patient becoming sexually active or by age 18-21; whichever came first. Now, the rules and recommendations have changed . . . and yes, it’s confusing.
ACOG – American College of Obstetricians and Gynecologists of which I am a fellow and consists of over 50,000 of my colleagues came out with some new guidelines for cervical cancer screening in November 2009. These recommendations came on the heels of the controversial new mammography screening guidelines. Although, it may seem that these guidelines were highly restrictive in the pursuit of cancer, they were really meant to be more cost-effective and less invasive. And if we take a deep breath and a step back the cervical cancer screening guidelines actually seem reasonable.
What’s new? Well, there were three major changes in cervical cancer guidelines by ACOG:
1. The age at which to start pap smears – should be age 21 regardless of sexual activity.
2. The pap interval – for those ages 21-29 every two years and for those 30 and over up to every three years is appropriate if they have had three normal paps and are low-risk. And for those who have had a benign hysterectomy, are low risk and have had three normal paps, routine paps may be discontinued.
3. The age at which to stop pap smears – seems to be by age 65-70. Provided that the patient is low-risk and had normal pap smears for the past 10 years, discontinuing pap smears at this age is adequate.
None of these guidelines are meant to replace the annual well woman exam which may still be performed without a pap smear. The annual exam is still typically required and recommended for a variety reasons. These reasons may included a woman’s general well-being, family planning, counseling for sexually transmitted diseases/infections (STDs/STIs), to refill birth control or hormone prescriptions, follow-up on breast examinations, check blood pressure, evaluate pelvic anatomy, and address other gyn conditions.
Cervical cancer occurs in approximately 11,000 women annually in the U.S. and accounts for approximately 4,000 deaths each year. Risk factors for cervical cancer include early onset of sexual activity, increased number of sexual partners, history of STDs/STIs, high risk HPV, history of abnormal pap smears with moderate or severe dysplasia (pre-cancerous changes of the cervix), smoking, HIV or immunocompromised patients, diethylstilbestrol (DES) exposure, poor nutritional status, obesity, teen pregnancy, low income, and in some cases family history. Cervical cancer is most common between the ages of 40-55. Cervical cancer by nature is slow growing and occurs over the course of many years. It is typically diagnosed in women who have not ever had a pap smear or have not had one within the past five years.
Over 95% cervical cancers are caused by a high risk form of HPV – Human Papilloma Virus and 75% of all sexually active adults will have had some form of HPV in their lifetime. Also, HPV infection is more common after the onset of sexual activity and more prevalent in the adolescent population. However, these young women’s immune systems will clear 60-70% of the infections in one year and up to 90% by two years. Meaning most of these new infections will regress and be unlikely to cause cervical cancer. The incidence of cervical cancer under the age of 21 is about 1 in 1,000,000.
So, it makes sense to perhaps wait and test these teens as young adults rather than when they first become sexually active as most will have fought off their HPV infection and lowered their risk for cervical cancer. If they are tested earlier they are likely to have significantly abnormal pap smears which will result in further testing and procedures that are both invasive and can be harmful to their future fertility. These procedures can increase their risk factors for incompetent cervix, cervical scarring, cesarean section and preterm birth in the future.
Although HPV can cause pre-cancerous changes and lead to cervical cancer, it does not do so quickly. Cervical cancer is a slow growing cancer and the disease process takes many years to develop so the two-three year interval on pap smears in a low-risk population seems reasonable.
As for stopping pap smears altogether on those who have had a hysterectomy or are over 65-70 years, well, I struggle with this guideline the most. Logically and statistically, I get it and understand why this guideline has been recommended, but anecdotal evidence speaks to me as I have had several patients with either vulvar or vaginal cancer over the years. It also concerns me that this might possibly be the population that may skip their “annual” exams if no pap smear is needed which may lead to inadequate overall care of the patient. It may not be cost-effective to perform a pap and highly unlikely that these patients are at risk for cancer, but I do feel this is an informed decision that the patient will need to make in conjunction with her doctor.
There are still several factors which will ultimately impact these cervical cancer guidelines. One is the use of the HPV vaccines, Gardasil or Cevarix. Gardasil is FDA recommended for girls ages 11 and 12 and approved for girls/women ages 9-26. It has also recently been FDA approved for boys/men as well. Gardasil has been tested extensively and approximately 40 million girls/women worldwide have been vaccinated. It is considered safe and protective against HPV types 16 & 18 which are the cause of 70% of cervical cancer and types 6 & 11 which are the cause of 90% of genital warts. Cervarix has been distributed to about 7 million girls/women worldwide and is FDA approved for ages 10-25. Ideally, either vaccine should be given prior to onset of sexual activity and is thus, most protective. Some protective benefits may occur in previously sexually active women if they are not already infected with HPV or these particular types of HPV as well. Studies are underway to test the benefits, if any, of the HPV vaccine in women older than 26 years of age. The full impact of the HPV vaccine on cervical cancer will likely not be known for 15 years, but for now vaccinated women will still follow the same new screening guidelines.
Another question that remains is whether to do HPV tests on all patients. Most of us use HPV testing in patients with abnormal pap smears, mainly ASCUS, but the benefits of using it routinely remains to be seen and is still uncertain. ACOG recommends that HPV testing not be done on patients under 30 years of age due to the high likelihood of transient positive results. But, HPV testing may be done as co-testing along with a pap on those low risk patients over 30 years old. And if the pap and HPV testing are both negative, ACOG advises that the patient not be rescreened prior to three years.
Now, back to the original question – to pap or not to pap? Cervical cancer, although slow growing, can be a deadly disease and must be taken seriously. The new guidelines and decreased intervals of pap smears may be adequate to diagnose cervical cancer, but both the doctor and patient must feel comfortable. For a low risk patient, it is important that the doctor communicates these changes and discusses these guidelines with the patient and involves her in the process and course of action. Although reasonable, these screening guidelines must be individualized based upon the patient’s history and needs and discussed with her. Additionally, it is essential that each woman still undergo a well-woman annual exam with or without a pap smear for her overall health and wellness.
Vandna Jerath, MD