The Pap test, also known as the cervical smear test, was named for its inventor George Papanicolaou and is used to detect cervical cancer in its earliest, most treatable stage. Records show that since the test’s introduction in the late 1940s, the death rate from cervical cancer in North America has dropped more than 70 percent.
One reason for the success of Pap tests is that most cervical cancers develop slowly; cells can take several years to become cancerous. Regular screening and pelvic exams lead to detection in plenty of time for treatment and also minimize the long-term risks of a single false-negative result.
But despite this impressive achievement, some 400 North American women die each year from a disease that, doctors say, is nearly 100 percent curable if caught early. According to one survey, many American and Canadian women are not being tested, and the proportion is increasing. Inadequate testing, the misinterpretation of test results, and the failure to follow up on abnormal results are other concerns often cited by medical experts in this field.
When should a woman take the test?
All women who are, or ever have been, sexually active need the Pap test. It should be done within six months of first having sexual intercourse, and 6 to 12 months later. Thereafter, a woman may repeat the test at one to three years’ intervals depending on the guidelines set by the health department in her area. Tests are performed by general practitioners, most family planning clinics, and well woman clinics.
The Pap test is a risk-free procedure, and the cervical smear itself takes only a few seconds. A clinician scrapes away some cervical cells, which are examined for abnormalities by a medical laboratory technologist, who prepares the test result.
What are negative and positive results?
A negative result indicates that the cells appear normal. A positive result indicates that the cells are abnormal, which may suggest a precancerous or cancerous condition. To confirm this result, follow-up tests include repeat smears or a colposcopy (the examination of the cervix with a viewing instrument) and a biopsy (the removal of cervical tissue for microscopic analysis).
Are the test results accurate?
Screening isn’t perfect, and the estimated error rate ranges from 5 to more than 20 percent. This means there will be false positives and false negatives. A false positive suggests abnormalities when none exist. Although this can be frightening, additional testing will reverse the result. A false negative suggests that the cells are normal when they are not. Regular testing is essential to avert the potential risk of a false negative result.
To help ensure the accuracy of test results, health authorities in the United States and Canada have set a guideline limiting the number of smears a technologist can handle to 8 to 10 per hour. Computer software for screening, ranking, and double-checking also help to reduce human error and improve efficiency.
To boost your chances of receiving an accurate result, schedule a test for 10 to 20 days after your period begins. (Blood and sloughed-off cells make it harder to see abnormalities.) Also, be sure to refrain from sexual intercourse and douching for two days before the test.