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THE PROPOSED “NEW” APPROACH TO PAP SMEARS
(June 2004)

Every year, 50 million PAP smears are done to prevent invasive cervical cancer. About 7 percent show some abnormality, everything from abnormal cells, the meaning of which is not known, to cancer. The PAP test has been extraordinarily beneficial, resulting in a 70 percent reduction in the United States of cases and deaths from invasive cervical cancer (but, cervical cancer is still a huge problem in so-called developing countries where adequate screening for cervical cancer is not done). At present in the United States, 13,000 women will develop invasive cervical cancer and 4,100 will die from it each year. Of those women, almost two-thirds have not had proper and regular PAP screening. That is defined as a PAP test at least every three years. Healthful Life recommends a PAP smear every two years; if that criterion is used, the percentage of women with cervical cancer that probably could have been prevented by proper PAP smear screening would be even greater than two-thirds, probably between 70 and 75 percent.

The good news is that the PAP smear as done now is very effective. The major preventive approach to invasive cervical cancer is to get all women to be screened with PAP smears starting at age 20 and continuing until at least five years after cessation of sexual activity (because cervical cancer occurrence increases with age, a good argument can be made for doing PAP smears until age 80). With regular PAP screening, we could reduce the invasive cervical cancer cases by two-thirds to three-quarters. That would be a huge accomplishment.

The PAP smear is not perfect. There may be errors because of problems with collection of the specimen or reading it. But, cervical cancer ordinarily develops slowly and regular screening (especially Healthful Life’s every two years) will usually allow any abnormal cells to be picked up in time to treat the local cancer before it turns invasive.

What about the newer PAP tests, such as the liquid PAP? They do have some advantages, but these are marginal, reduction in invasive cancer has not been clearly shown, and they are more expensive.

What should be done with a finding of abnormal cells? That was the subject of an article in the Journal of the American Medical Association, April 24, 2002. Each year, about 50 million women have PAP tests; about 7 percent of these (some 3.5 million women) are found to have abnormal cells. There are multiple types of abnormal cells. One is a high grade abnormality. There is no quarrel about what to do with that - examine the cervix directly; in most cases, biopsy; if early cancer is present, remove it

Then, there are low-grade abnormalities or cells that appear abnormal, but whose significance is unknown (called ASCUS). What is known is that the risk of developing cancer for those with ASCUS is less than 1 percent.

Healthful Life is concerned that, for lesser findings (those ASCUS cells or low-grade abnormalities), we will be doing a lot of expensive tests and biopsies without evidence that those expenditures and biopsies will either reduce the occurrence of invasive cervical cancer or save lives.

The evidence clearly points to a group of viruses called papilloma viruses as playing a major role in cervical cancer. It has been proposed that, in addition to PAP tests, women have cervical specimens tested for papilloma viruses. That would at least double (perhaps triple) the costs of screening with the PAP smear alone. As pointed out in a thoughtful editorial in The New England Journal of Medicine, February 6, 2003, by Thomas C. Wright Jr MD and Mark Schiffman MD, there would be a real danger of overuse. Sexually active women often carry these viruses transiently in their cervix, but only those who carry certain high risk types of papilloma viruses persistently for long durations are at risk for cervical cancer. So, most positive tests, even if repeated and still positive at, say, 6 months later, will be false positives and create anxiety as well as the likelihood of unnecessary expenditures and over treatment. Testing for these viruses would provide useful information, but the fact that, most of the time, finding a high risk papilloma virus would not indicate a high likelihood of cervical cancer is a real problem in regard to adding papilloma virus detection to the PAP smear. One suggestion is to do the papilloma virus detection test only in women with ASCUS. That seems reasonable. It would remove one-half the women with ASCUS from the possible high risk category, but, even if a women with ASCUS has dangerous types of papilloma virus, it is not clear how great the risk of cervical cancer really is.

So, there is still a lot of uncertainty about three aspects of cervical cancer screening - the use of liquid PAPs and similar modifications of the routine PAP smear, what to do about ASCUS and the usefulness of papilloma testing; what is absolutely clear is the necessity for regular standard PAP tests.

The recommendation by many experts is after two normal PAP tests at yearly intervals, a PAP smear every three years is satisfactory. Healthful Life continues to be a little more conservative - we recommend a PAP test every two years as part of the comprehensive prevention examination.