Rescreening Pap smears ineffective, study says
Regular tests greatest deterrent to cervical cancer
Is computer technology always the better choice in providing the best health care, in terms of cost and meeting patients' needs? Disease managers face this issue regarding PapNet, a computerized device for rescreening Pap smears. Although PapNet shows a higher accuracy rate in detecting abnormal cervical cells, a study appearing in the Journal of the American Medical Association found that it's only slightly better, yet costs 20 to 30 times more than traditional manual scanning. And, for the most part, insurance companies do not cover PapNet, so the patient bears the extra cost.
Timothy O'Leary, MD, PhD, pathologist and chairman of the department of cellular pathologists at the Armed Forces Institute of Pathology in Washington, DC, conducted research on PapNet's effectiveness. O'Leary says the more expensive PapNet is not necessary. The greater issue in detecting cervical cancer is not the rescreening process, but getting screened in the first place, he says.
"The best cancer prevention is getting a Pap smear regularly," says O'Leary, explaining that people tend to think of cases in which women got cervical cancer because their cancerous cells were missed during a Pap smear screening.
"That does happen at times, due to human error," he admits. "But far more cases of cervical cancer are due to a lack of screening in the first place."
Eighty percent of cervical cancers are diagnosed in women who haven't had Pap smears in the past five years, says O'Leary, adding that one-third of all women don't get screened regularly.
"Most patients who are not getting screened are over 50 years old, and most new cancers occur in women over 50," he says. "So, there's a greater need to address patients who avoid Pap smears altogether."
O'Leary suggests clinicians consider the most important aspects of screening women:
· Regular screening as infrequently as every three years will reduce cancer up to 90%.
· An adequate smear by a nurse practitioner or physician is critical. "All labs have received smears that are inadequate or marginally adequate," O'Leary says.
· The quality of the lab, which should be accredited by the College of American Pathologists in Chicago, is critical.
Rescreening, O'Leary says, is another matter altogether.
O'Leary studied 5,478 Pap smears and compared manual rescreening with PapNet to determine the cost-effectiveness of the computerized technology in relation to its accuracy.
"We wanted to find out what PapNet costs to catch additional cases above and beyond manual rescreening," says O'Leary.
"We did a double-rescreen manually before using PapNet - and we did catch a few cases that were missed on the manual rescreen. But you have to look at an awful lot of cases to do that." Results of the study showed that PapNet found one more abnormal smear in every 913 cases.
"Our analysis and observation was that PapNet was expensive, based on cost assumptions that reflected our costs," he explains. "With PapNet we did find a few atypical cells of undetermined significance, but could not tell for sure if they were pre-cancerous - and, it was very expensive to do so." O'Leary says that manual rescreening cost about $3 per slide; PapNet costs about $50 per slide.
O'Leary says his study was based entirely on price associated with computer-assisted rescreening - not on PapNet's overall effectiveness.
"PapNet is safe and effective, but that doesn't mean that the more expensive rescreening method is the best," he says. "It's OK. If PapNet becomes less expensive, it would make a lot of sense to use."
Neuromedical Systems in Suffern, NY, which manufactures PapNet, obviously differs with the findings. The manufacturer claims, first of all, that O'Leary had a "skewed" population for his study of younger, healthier military women vs. the general population. O'Leary says his group represented the norm.
"We present in the study what our distribution was: 12- to 88-year-old women, including those in the military, independents, and retirees. Yes, this group has good access to regular health care and is not economically disadvantaged," O'Leary says. "But, is that a material issue? I honestly don't know. All managed care patients have similar access to the health care my research group has. So, in that case, we have comparable system.
"One thing I'm uncertain of, though, is the quality of the lab or gynecologists that patients have - there's an infinite variation out there."
PapNet protests
Neuromedical Systems argues that its product is worth the cost. "We've had 22 studies published on the favorable results of PapNet," says Andrew Panagy, vice president of marketing and sales of Neuromedical Systems. Responding to O'Leary's research, Panagy says, "Despite the double manual rescreening, PapNet still detected abnormalities. It's amazing PapNet found any at all."
And addressing the concern that PapNet wasn't worth the cost that patients incur, Panagy says, "That's what used to be said about mammograms, but since they have helped detect breast cancer, patients' attitudes have changed about paying out-of-pocket for mammograms. Patients are willing to pay even if insurance doesn't cover PapNet because you can't put a dollar value on the life years gained."
In addition, Panagy says that a growing number of insurance plans are covering PapNet rescreening.
"For its accuracy, PapNet is cost-effective," says Panagy, who adds that Neuromedical Systems is seeking FDA approval for PapNet to be used as a primary screening method.
Let the patient decide
Some health care providers, indeed, clearly support PapNet and say that the choice is ultimately the patient's.
"Who's determining how to spend this money? It's the patients who should decide," says Brian Levitt, MD, OB/GYN at Perimeter OB/GYN Care in Decatur, GA, who says he was the first physician to use the PapNet technology in Georgia. Levitt gives each patient a consent form to accept or refuse PapNet.
"Although many insurance companies don't cover rescreening unless there's an abnormal result, most patients are willing to pay the $49," says Levitt.
Some women have three Pap smears in a year, he says.
"The first is abnormal, the next one is normal," Levitt says. "They're not sure which to believe, so they have a third, going to a different doctor each time.
Why shouldn't PapNet be available to them? he asks.
Levitt says that one in nine American women will develop breast cancer; four in 10 will develop some type of cancer in their lifetime.
"As a result, there are cancer-phobic patients, and they want peace of mind," he says. "Almost every single breast cancer patient I have says 'yes' to PapNet because they feel that the additional cost is nothing compared to cancer."
Levitt says that the Armed Forces research had the "best pathologists and cytologists in the world" reading the Pap smears vs. "normal, regular labs with a higher-risk population."
"If a lab is reading a slide on a Friday afternoon, there's going to be more individual observer error because they're tired," he maintains.
Levitt says that PapNet is more accurate because the computer scans a slide and tags where the abnormal cells are located. "When a cytologist manually scans a slide, they don't look at every single cell," he explains. "PapNet looks at every single cell [numbering roughly 300,000 on a slide], then selects the 25 most abnormal ones.
"Then, PapNet shows the cell size on half the computer screen vs. someone looking at small cells under a microscope, so the projection is much larger."
Levitt recommends PapNet especially for high-risk groups, such as women who have had multiple sex partners, previous abnormal Pap smears, a history of sexually transmitted disease, a family history of cancer, an uncircumcised partner, or women who smoke.
Screening tool is critical
Judith Petterson, MSN, certified perinatal nurse practitioner at Medical Group of Northern Nevada in Reno, agrees.
"Women are reservoirs for infection, so it's critical to have a screening tool for more accuracy," she says. "What if a cytologist misses an abnormal smear two years in a row, so a patient forgoes a Pap smear the next year because she thinks there's no problem?"
Petterson adds that there are three variables in collecting a Pap smear:
· collecting a good sample;
· making sure the sample is not mixed up in the lab;
· having a knowledgeable cytologist reading the sample.
If any one of them causes an error, it will alter a correct reading, Petterson says. PapNet serves as a check and balance, she adds.
"I offer this as an option to all my patients because you don't have to be in an at-risk group to contract an abnormality," Petterson says. "They understand it's an extra cost, but the patients who select PapNet feel it's worth it."
In fact, the protocols for Pap screening should incorporate PapNet, she maintains.
[For more information on using PapNet, contact:
· Timothy J. O'Leary, MD, PhD, Chairman, Department of Cellular Pathologists, Armed Forces Institute of Pathology; Public Affairs Office, Building 54, 6825 16th St. NW, Washington, DC 20306-6000. Telephone (202) 782-2113. Fax (202) 782-9376. E-mail: [email protected].
· Andrew Panagy, Vice President, Marketing and Sales, Neuromedical Systems, Two Executive Blvd., Suffern, NY 10901. Telephone: (914) 368-3600. Fax: (914) 368-3896. Patient information line: (800) PAP-NET4.
· Brian Levitt, Perimeter OB/GYN Care, 2675 N. Decatur Road, Suite G-05, Decatur, GA 30033. Telephone: (770) 39O-BGYN. Fax: (404) 501-7609.
· Judith Petterson, MSN, Certified Perinatal Nurse Practitioner, Medical Group of Northern Nevada, 75 Pringle Way, Suite 801, Reno, NV 89502. Telephone: (702) 789-3003.]
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