Feature Archive

Pap Technology

New techniques can better detect cervical problems.

WebMD Feature Women have been going to their gynecologists for Pap tests for more than 50 years. And their vigilance has paid off: Mortality rates from cervical cancer have dropped 70%, according to the American College of Obstetricians and Gynecologists. But a woman's chance of getting a false negative -- a result that says she's healthy when she really has cancer or pre-cancerous cells -- is still between 10 and 25%, according to the ACOG.

Hoping to improve those odds, manufacturers have introduced several new methods that have been approved by the Food and Drug Administration (FDA). These new methods -- whose brand names include Papnet, Autopap and ThinPrep -- use computers to help analyze slides.

Luis Galup, a pathologist at the South Bend Medical Foundation in South Bend, Ind., is a strong advocate of the ThinPrep system. Instead of smudging a slide with cells scraped from a woman's cervix -- the conventional method -- the cells are swirled into a tube filled with a preservative and sent to a lab. In the lab, technicians filter out the blood, mucus, and other debris. A random sample of the fluid is then placed onto a slide.

Easier-to-Read Samples

According to Galup, ThinPrep's method of collection keeps the collected cells from drying out, which results in a more uniform, debris-free sample. "It's so much easier to read," Galup says. An important advantage, he adds, is that the same ThinPrep fluid can be used to test for human papillomavirus, or HPV, which is associated with cervical cancer.

"In our eyes this was such a significant improvement that, in good conscience, we could not continue to accept conventional pap smears," Galup says. That decision caused problems for the lab, because many insurers would not pay the extra $15 to $20 for the procedure. Through public awareness campaigns, however, the lab has been able to regain any business it lost when it switched to ThinPrep. "The number of Pap tests we are analyzing is greater than before," Galup says.

Despite agreement among physicians that the ThinPrep Pap test is easier to read, cost is the number one reason the method is not yet widely used. "The coverage for the test by insurance companies is still uncertain," explains Laurie Green, an obstetrician-gynecologist practicing in San Francisco. "ThinPrep costs more than double that of a conventional Pap test in some cases. That's the kind of across-the-board increase that could disrupt the whole system," she says.

Quality Depends Upon Individuals

Green also believes the benefits do not outweigh the costs. "The bottom line is that the quality of the reading is dependent on the quality of the individual reading the slides," she says. "I am not convinced that the lab I use will give me that much better interpretations of slides."

Anita Lasala, a Manhattan-based ob-gyn agrees that conventional Pap smears have been satisfactory: "We've had no problems." Her practice only uses ThinPrep when it has been requested by a patient or when a smear has had to be redone because it was thin and hard to read. She admits both ThinPrep and Papnet make slides easier to read. "In some places, strain on human eyes is an issue," she says. In New York City, however, there are more than enough labs and an abundance of experienced technicians, she adds.

According to the ACOG, more research needs to be conducted on all of the new systems, and they are not yet standards of practice. The group also points out that the most effective way for women to prevent cervical cancer is to participate in screening programs, regardless of what kind.

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Last Editorial Review: 1/30/2005 10:43:50 PM