PAP Tests approved by the Federal Drug Administration
Description
This article is from the Health Articles series.
PAP Tests approved by the Federal Drug Administration
Tests approved by the Federal Drug Administration include:
1.The liquid-based cytology sample preparation. (Cytyc Corporation's ThinPrep System, and Tripath Imaging Inc's AutoCyte PREP System ("PREP"). In these systems, instead of smearing cells on a slide, cells are rinsed into a liquid preparation and sent to a lab. The liquid-based test reduces debris and cell clumps. It also homogenizes the specimen.
"Imagine a cereal bowl with raisins," says Solomon. "If the raisins were clumped together and you stuck a spoon in the bowl, you might or might not come up with raisins. If you dispersed them evenly, your chance of coming up with raisins in a spoonful is more likely." The liquid-based technique, she says, is thus more likely to produce a representative subsampling.
Company claims for the increased sensitivity of these liquid-based tests over the conventional Pap test range from 65 percent to 157 percent.
2. Computer-assisted screening. Several automated systems exist to re-screen Pap slides after an initial human inspection using computer-generated images. However, an even newer technology, the AutoPap Primary Screening System (TriPath Imaging, Inc.), is now FDA-approved for screening prior to human inspection. The AutoPap System uses a high-speed video microscope, image interpretation software and specially designed field-of-view computers to image, analyze and classify cells within the Pap smear slide.
A Pap test should be done when a woman is not menstruating; the best time is between 10 and 20 days after the first day of the menstrual period, according to information from the National Cancer Institute. The NCI's online CancerNet (cancernet.nci.nih.gov) provides answers to questions about Pap tests.
In addition to the Pap test, there is also a test that detects HPV (human papillomaviruses), which is a major risk factor for cervical cancer. Nearly all cervical cancers show evidence of HPV, although not all cases of HPV develop into cervical cancer, according to Solomon.
The HPV test is not an appropriate primary screening of all women, Solomon says. However, if a patient's Pap results indicate that the cells don't appear to be normal, but it is unclear what is wrong with them - something cytotechnologists call ASCUS (Atypical Squamous Cells of Undetermined Significance) - her physician may suggest HPV testing, according to Solomon. Another option, she says, would be to repeat the Pap smear in four to six months.
Home tests in the future?
Home Pap and HPV tests are on the horizon, although none has yet been approved by the FDA. The tests would allow women to collect samples of their own vaginal cells for laboratory analysis. Some doctors have pointed out that a traditional Pap test is more specific, and they caution that the convenience of an at-home test wouldn't be worth much if women don't act on the results.
"To the extent that a home test would be used by women who otherwise would not go for a conventional Pap test, it would be a benefit," Solomon says. "However, for women who already go for Pap testing, a less sensitive test would detect fewer abnormalities."
What type of testing a woman has depends on what she and her doctor agree is best. But getting tested is critical, Solomon says, because finding and treating an abnormal condition early can save lives.
- Risk factors for cervical cancer Sex before age 20
- Multiple sexual partners (or male partners who have had multiple partners) Human Papillomavirus
- Human Immunodeficiency Virus
- Smoking
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