- Published on Tuesday, 20 April 1999 20:00
- Written by Jim McCarrick, M.D., Ph.D.,
and Arian Dasmalchi
As a gynecologist, I generally perform 10 to 20 Pap smears a week. I think it's fair to say that most women, while recognizing the importance of this test designed to detect cervical cancer, would prefer to limit their time on the examination table.
Thanks to a new technology called ThinPrep, patients can now leave their doctors' offices fairly confident that they won't have to return due to a Pap test cell-sample error.
Palo Alto Medical Foundation (PAMF) and other medical centers nationwide have begun to use ThinPrep, which is significantly slashing the number of Pap smear re-tests. Research indicates that the new technology increases sensitivity and specificity. Overall, it's a more accurate Pap test.
While ThinPrep can cost twice as much as the conventional test, which runs about $35, it will reduce long-term costs by decreasing the need for re-tests. Women need to be aware that not all health insurance plans cover ThinPrep, although I suspect this will change as the technology becomes more widely known and used.
The conventional Pap test, developed by Dr. George Papanicolaou more than 50 years ago, has cut the U.S. cervical cancer death rate by 70 percent since the 1950s. It can detect precancerous cells and cancer in
its earliest, most treatable stages.
The Pap test has been a lifesaver for many women, yet there is room for improvement. More than 14,500 American women are diagnosed with cervical cancer annually and 4,800 of them die because the cancer was detected too late, according to the National Cervical Cancer Coalition.
With the conventional Pap test, the physician prepares a slide for the lab before the sample dries and while the patient is still on the examining table. The physician smears the sample on the slide, then sprays it or dips it in a preservative. Because the physician ends up collecting blood, mucus and inflammation on the slide, lab technicians often find it difficult to find abnormal cells.
With ThinPrep, the sample goes straight into a small vial of fixative, which lessens the loss of accuracy. At the lab, the bottle goes into a special machine that filters the sample to produce a thin even layer on a slide. The process renders blood and other extraneous material transparent, and virtually eliminates cell distortion due to slide preparation.
Whether ThinPrep will change survival rates is still being studied. It is clear, however, that ThinPrep is a step in the right direction as we continue searching for ways to detect cervical cancer in its early, most treatable stages.
Dr. McCarrick is an obstetrician/gynecologist at the Palo Alto Medical Foundation's Women's Health Medical Group in Portola Valley.
Dasmalchi is a consultant and writer.