The Pap smear is a simple, relatively painless and inexpensive method for detecting precancerous and cancerous conditions of the cervix (the lower end of the uterus). It is considered by many to be the best cancer-screening tool available. The procedure as named for Dr. George Papanicolaou, who developed the test about 40 years ago.
The Pap smear is a routine part of a gynecologic examination. Properly performed, it is highly effective in detecting abnormal cervical cells before they become cancerous. In fact, since the development of the Pap smear, the number of deaths from cervical cancer has been reduced by 70%.
You will be asked to lie down on your back on the gynecologic examination table with your buttocks at the edge of the table and your knees or feet supported in stirrups. The physician will place a metal or plastic instrument called a speculum into the vagina to expand its walls so the cervix can be seen. (Insertion of the speculum may cause slight discomfort. You should inform the physician if you are too uncomfortable.) The physician will then collect cells from around the opening of the cervix and its inner and outer surfaces using a cotton swab, wooden spatula or cervical brush. The cells are then smeared onto a glass slide (hence the name Pap “smear”) and preserved with a chemical solution to prevent them from drying and changing appearance.
After obtaining the Pap smear, your physician will conduct a manual examination of the uterus. By placing the fingers of one hand on your abdomen and gently pushing the uterus up with two fingers placed within the vagina, the physician will check for abnormalities.
The slide, along with some personal information (your age and gynecologic and obstetric history), is sent to a laboratory. A specially trained laboratory technologist examines the slide under a microscope and searches for abnormalities among the 50,000 to 300,000 cells found on the slide.
The Bethesda Classification System is a recently developed means of evaluating the Pap smear. It was devised at a 1988 workshop sponsored by the National Cancer Institute. This system provides three main types of information:
The first Pap test should be performed by age 18 or when a woman becomes sexually active. All women should have a Pap smear as part of a pelvic examination once a year. After three consecutive smears are normal, your doctor may recommend that the test be performed less frequently. However, women at high risk for cervical cancer should continue to have annual Pap smears.
A woman’s risk of cervical cancer is directly related to the number of sexual partners she has had: the greater the number of partners, the greater the risk. The risk is also increased when a woman’s sexual partner has had other partners. Recent studies show that half of all married women and from 70% to 80% of married men have had multiple sex partners. This means that nearly all women who are sexually active should have an annual Pap smear. Doctors have identified the following types of women as being high risk for the disease: