- Pap smear: the Papanicolaou (Pap) smear is widely used to screen for precancerous or cancerous changes in cervical cells.
- HPV DNA test: DNA testing for HPV is widely accepted both as an addition to the Pap smear and as a follow-up to abnormal Pap results. The most common HPV test detects DNA from several high-risk HPV types, but it cannot identify those specific types. Another test identifies DNA specifically from HPV types 16 and 18, the two types that cause most HPV-associated cancers. A third test can detect DNA from several high-risk HPV types and can indicate whether HPV-16 or HPV-18 is present. A fourth test detects RNA from the most common high-risk HPV types. All of these tests can detect HPV infections before cell abnormalities are evident, according to the National Cancer Institute (NCI).
Guidelines from various organizations, including the American College of Obstetricians and Gynecologists (ACOG), the U.S. Preventive Services Task Force (USPSTF) and the American Cancer Society (ACS), on cervical cancer screening recommend the following:
- Screening with a Pap smear for women ages 21 to 29 every 3 years
- Screening with a Pap smear and HPV DNA test for women ages 30 to 65 every 5 years (preferable), or every 3 years with Pap smear alone (also acceptable)
These organizations recommend more frequent screening for women with risk factors such as exposure to DES (diethylstilbestrol) in utero, previous diagnosis of a high-grade precancerous cervical lesion or cervical cancer, HIV infection, or a compromised immune system.
While previous guidelines for teens and young adults ages 13-20 suggested cervical cancer screening after becoming sexually active, current guidelines recommend against screening for this age group. Pap smears for women younger than 21 are not recommended because the incidence of cancer in this age group is very low. False-positive results may occur due to normal cell changes and are somewhat common. The false-positive results may generate unnecessary and costly treatment as well as emotional anxiety.
These guidelines recommend against screening for cervical cancer for women over the age of 65 who have had negative results on adequate prior screening. Guidelines define adequate prior screening as 3 consecutive negative Pap smears or 2 consecutive negative HPV tests in the prior 10 years, with the most recent within 5 years.
If someone has positive screening results, the doctor may use one or both of the following tests:
- Colposcopy: this follow-up test involves putting a vinegar-like solution on the cervix and checking it for abnormalities using a bright light and magnifying instrument. The colposcopy may include a Schiller test, which involves placing iodine on the cervix, causing normal cells to turn brown and abnormal cells to show up as white or yellow.
- Biopsy: if abnormal areas are found on the cervix, the doctor will remove small pieces of tissue for examination by a pathologist. A biopsy and microscopic evaluation are the only way to tell for sure whether abnormal cells are cancerous, precancerous, or reactive for some other reason.