Screening for Cervical Cancer

The US Preventive Services Task Force (USPSTF) has recently published updated recommendations on screening for cervical cancer.

The cervix is the bottom part of the uterus (womb) in women. The main symptom of cervical cancer is abnormal vaginal bleeding; however, very often, cervical cancer in its early stages causes no symptoms. This is why screening is important. Cervical cancer or precancer treated at an early stage can usually be cured. Treatment options include surgery, radiation therapy, and chemotherapy.

Two tests can be used for cervical cancer screening: a Papanicolaou (Pap) test and a human papillomavirus (HPV) test. One or both of these tests is recommended depending on a woman’s age and medical history.

A Pap test is done using a speculum (a device that looks like a duck bill) to keep the walls of the vagina open and a small brush or spatula to collect cells from the cervix. This is a quick procedure done in a doctor’s office. The cervical cells are then looked at under a microscope to identify cancer or abnormal precancerous cells.

An HPV test is also done using a sample of cells from the cervix. These cells are analyzed to look for the HPV virus, particularly high-risk HPV strains, which can infect cervical cells and cause cervical cancer in some women.

This USPSTF recommendation applies to women who do not have symptoms of cervical cancer and do not already have a diagnosis of precancerous cervical cells. The recommendation does not apply to women with in utero exposure to diethylstilbestrol (an estrogen medication that is mostly no longer used) or women who have a compromised immune system (for example, women living with human immunodeficiency virus infection).

The goal of screening for cervical cancer is to catch cervical cancer (or precancer) early; these cases are more treatable and curable than advanced cancer. There is good evidence that the Pap and HPV tests are good at finding cancer and precancerous cells. There is also good evidence that using these screening tests results in decreased rates of and deaths due to cervical cancer in women aged 21 to 65 years. Potential harms of screening involve additional testing, which can be more invasive (eg, biopsy of the cervix). In the case of a false-positive result or overdiagnosis (finding a cancer or precancer that never would have caused any health problems), unnecessary treatment may also have negative side effects. There may also be some psychological harm from a diagnosis of HPV infection. However, for most women, the overall magnitude of harm is small compared with the magnitude of benefit.

The USPSTF concludes with high certainty that the benefits of screening for cervical cancer substantially outweigh the harms in women aged 21 to 65 years. The USPSTF concludes with moderate certainty that the benefits of screening do not outweigh the harms in women older than 65 years who have had routine prior screening. The USPSTF concludes with moderate certainty that the harms of screening outweigh the benefits in women younger than 21 years of age. The USPSTF concludes with high certainty that the harms of screening outweigh the benefits in women who have had their uterus and cervix removed for reasons other than cancer.

Source: US Preventive Services Task Force. Screening for cervical cancer: US Preventive Services Task Force recommendation statement [published August 21, 2018]. JAMA. doi:10.1001/jama.2018.10897

Correction: This article was corrected on September 13, 2018, for an error in the illustration. This article was also corrected on August 27, 2018, for an omission in the illustration.