Last year, 10,000 women in the United States were diagnosed with cervical cancer and almost 4,000 died from this largely preventable disease. "Today" medical contributor Dr. Judith Reichman was invited onto the show to help educate women about cervical-cancer screening.
A bipartisan association called Women in Government just announced that in some states women are not getting appropriate cervical-cancer screenings. Best grades for screening were given to Delaware, Massachusetts, Illinois, Maryland and North Carolina. The worst grades went to Tennessee and Texas.
Let’s do a quick review: What is the cause for cervical cancer? Is it really a sexually transmitted disease?Yes. We know that 99.7 percent of cervical cancers are due to sexually transmitted viruses called the human patillomavirus (or HPV).
There are more than 30 types of genital HPV viruses; those classified as high risk HPVs are more likely to result in cervical-cancer abnormalities or high-grade lesions (HSIL) that lead to cervical cancer. Low risk HPVs are associated with cervical changes that are less likely to be precancerous (low grade lesions or LSIL) although on occasion, they can cause venereal warts. It probably takes three years for a persistent high-risk HPV infection to enter the cervical cells, take over their genetic direction and cause mutations. Hence cervical cancer in women under the age of 19 is rare.
HPV is very contagious during intercourse, and, unfortunately, condom use is not completely protective because the virus can spread through skin-to-skin contact beyond the genitals. As a result, HPV is found in more than 70 percent of sexually active young adults. In addition, because there are virtually no symptoms, most are unaware that they have it. (Only 1 percent develop visible venereal warts.) In other words, it’s become part of our normal vaginal “flora and fauna.”
Fortunately, most HPV infections do not lead to a pre-cancer or cancer of the cervix. Most infections are temporary, especially in younger women. In adolescence and young adulthood, 70 percent of high-risk HPV types regress or disappear after three years. And 90 percent of low-risk HPVs disappear in that time. If we perform cervical biopsies on young women who have cervical cell changes, we find that the low-grade lesions spontaneously regress in 90 percent of women. We’re not too sure about regression of high-grade lesions, but studies have found that it takes at least three years for these lesions to progress into early cancer. This means that if we wait three years from the onset of intercourse (when a woman can become infected) to begin cervical cancer screening, we shouldn’t miss any cervical cancers.
How does a woman know she has an HPV infection? Should she routinely be checked for this type of virus? I have to emphasize, lack of symptoms does not mean that a woman (or her partner) is virus-free. And in sexually active younger women, there is a good chance that an HPV viral test will indeed be positive.
I can tell you from clinical experience that receiving the diagnosis “You have high-risk HPV” can cause a reaction of overwhelming consternation for the patient (and, if involved, her mother.) Questions such as: “When did I get this? Who gave it to me? Does this mean that I can give it to all my future partners? Will it affect my babies?” follow.
Unfortunately, they can’t be answered with any certainty (although the possibility of affecting future children is highly unlikely). Nor can I prescribe a cure. The only response that I and other physicians can give about an HPV diagnosis is that this virus (like most viruses) will most likely subside and disappear. This, of course, is usually an unsatisfactory answer.
We do know, though, that persistence of high-risk HPV is worrisome. And the older we are when we get it, or the longer we have it, the more at risk we become for cervical cancer.
Will a Pap smear indicate if HPV is present? The Pap smear detects changes in the cervical cells that occur as a result of persistent viral infections. Liquid Pap smears, in which the cells are placed in a solution and filtered (so that they can be separated and stained) can also be used for “reflexive HPV testing.” This means that if mildly suspicious changes in the cells are noted, the leftover fluid is checked for HPV viruses.
If high-risk viruses are present, the doctor is notified and further testing with colposcopy (a special microscope that allows a physician to better view the cervix) and biopsy is indicated. However, if more severe pre-cancerous changes are found in the Pap, it’s not necessary to do HPV testing since we assume that this will be positive.
If all “bad” Pap smears are due to HPV infection, should women just get HPV testing and forego Pap smears? There are indeed studies that show that testing for HPV is more sensitive than cervical cytology (the Pap smear) for the detection of pre-cancerous cells and cervical cancer. And when the HPV test is combined with a Pap smear it has what we call a negative predictive value of 99 percent to 100 percent. That means that the chance of missing a pre-cancer or cancer is approximately 1 in 1,000 (which is exceptional when we are talking about a screening test). But right now this is not generally considered the way we should screen younger woman (under 30) who are less likely (than those over 30) to be in stable, long-term relationships. These women will have too many positive HPV results. However, if a woman over 30 in a stable relationship is negative for HPV and also has a normal Pap smear, and she is low risk (i.e. she and her partner are monogamous, she never had an abnormal pap, doesn’t smoke, doesn’t take steroids, and was not DES-exposed during her mother’s pregnancy), these two negative tests virtually assure her that nothing has been missed. She doesn’t need to repeat cervical cancer screening for three years.
If we know HPVs cause cervical cancer, will vaccines against HPV prevent it? Currently, vaccines against several of the most high-risk types of HPVs are being investigated. Preliminary results show that they can prevent persistent viral infection and subsequent pre-cancerous changes. The hope is that, in the future, pediatricians and those caring for adolescents will be able to give a protective vaccine before any exposure to HPV (in other words, before this young population becomes sexually active) and thus virtually eliminate cervical cancer. One of these vaccines may be submitted for FDA approval by the end of 2005.
So what should women do to ensure that they get an A+ in their cervical-cancer screening?
Here is the schedule that is currently recommended:
- Start three years after the onset of intercourse and no later than age 21.
- Repeat every year (conventional non-liquid Pap smear) or every one to two years (liquid-based Pap test)
- Repeat liquid Pap every two years if “low risk” and have had three normal consecutive Pap smears. HPV screening should also be considered to establish that the result is conclusive. If this and Pap smear are negative, and “low risk” status continues, repeat in three years.
- Stop Pap smears if had three normal Pap tests and no abnormal results in the last 10 years.
- No need for Pap smear if hysterectomy was done for benign disease and the cervix was removed.
Dr. Reichman’s Bottom Line: Let’s remember that since Pap smears were introduced more than 50 years ago, cervical cancer mortality rates in the United States have decreased by 75 percent. (In addition, half of the cervical cancers in the U.S. occur in women who have never been screened, and another 10 percent occur in women who have not been screened in the past 10 years.) So let’s not discard a test that saves lives. For those women who want further guarantees that they can safely wait between Pap smears, adding HPV testing is appropriate. And perhaps in the future, HPV testing alone will become the standard method used to determine who should get a Pap smear and how often it should be performed. Better yet, future vaccines may free a new generation of women from cervical-cancer concerns.
Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," published by William Morrow, a division of .
PLEASE NOTE: The information in this column should not be construed as providing specific medical advice, but rather to offer readers information to better understand their lives and health. It is not intended to provide an alternative to professional treatment or to replace the services of a physician.