Testing for cervical cancer
New recommendations from the American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology
Cervical Cancer Facts
The cervix is the lower part of the uterus or womb. It is at the top of the vagina. Cancer that starts in the cells of the cervix is called cervical cancer.
Changes in the cells of the cervix can lead to cervical cancer. These cell changes are caused by a virus called the human papilloma virus (HPV).
If cervical cancer occurs, there are tests to find it early when it is small and easier to treat. These tests can also find cell changes before they become cancer.
Most deaths from cervical cancer could be stopped if more women had tests to find cervical cancer early.
HPV and Cervical Cancer
Most HPV infections go away by themselves and cause no symptoms or cell changes. Sometimes infections with certain types of HPV that don't go away can lead to changes in the cells of the cervix. These changes are called precancers or high-grade lesions. They may progress over many years to cervical cancer if not treated. It often takes 10 years or more for a precancer to become cancer. The goal of cervical cancer screening is to find precancers so they can be treated before they progress to cancer.
Understanding Tests for Cervical Screening
There are 2 types of tests for cervical cancer screening. Both tests are done on samples of cells that a doctor, nurse, or physician assistant removes from your cervix. They gently scrape or brush the cervix with a special instrument.
- 1)The Pap test. The test can find early cell changes that are not yet cancer. If cell changes are found, they can be treated. This can prevent them from becoming cervical cancer. This test also can find cervical cancer at a stage that is easy to treat.
- 2)The HPV test. This test finds certain HPV infections that can lead to cell changes. These cell changes can progress to cervical cancer if not treated. If cell changes are found, they can be removed from the cervix. This can prevent them from becoming cervical cancer. HPV infections are very common. Most HPV infections go away by themselves and cause no symptoms or cell changes. In most cases, they do not go on to cause cancer.
These tests are good, but they are not perfect. They can sometimes report that there are precancers present when there really are not. These “false-positive” results can lead to treatments that are not needed. Pap tests have been done yearly in the past, but now we know that yearly Pap tests are not needed. In fact, yearly Pap tests can lead to harm from treatment of cell changes that would never go on to cause cancer. The new screening recommendations (shown below) keep the benefit of testing but lower the risks of unneeded treatment (called “overtreatment”).
Regular cervical cancer screening is not helpful before age 21 years. Women should start screening at age 21 years and be tested every 3 years with a Pap test. At age 30 years, HPV tests are a useful addition to Pap tests. (They are not useful for screening in younger women.) If a woman tests positive for HPV, she will need further testing to find out if she is likely to have a precancer. If she tests negative on both the Pap and HPV tests, her risk of precancer and cancer is so low that she does not need to be tested again for another 5 years.
- 1)Cervical cancer screening should begin at age 21 years. Women younger than age 21 years should not be tested with either the Pap test or the HPV test.
- 2)Women between the ages of 21 and 29 years should have a Pap test every 3 years. HPV testing should not be used in this age group unless it is needed after an abnormal Pap test.
- 3)Women between the ages of 30 and 65 years should have a Pap test plus an HPV test (called “co-testing”) every 5 years. This is preferred, but it is also okay to continue to have Pap tests alone every 3 years.
- 4)Women older than 65 years who have had regular Pap tests that were normal should not be screened for cervical cancer. Once screening is stopped, it should not be started again. Women who have had serious cervical precancer should be tested for at least 20 years after that diagnosis, even if screening continues past age 65 years.
- 5)A woman who has had a hysterectomy (with removal of the cervix) for reasons not related to cervical cancer and who has not had cervical cancer or serious precancer should not be screened.
- 6)A woman who has been vaccinated against HPV should still follow the screening recommendations for her age group.
Making Your Pap Test More Accurate
There are things you can do to make your Pap test as accurate as possible:
Try not to schedule your appointment for a time during your menstrual period.
Do not douche for 48 hours (or 2 days) before the test.
Do not have sex for 48 hours (or 2 days) before the test.
Do not use tampons, birth control foams or jellies, or other vaginal creams or vaginal medications for 48 hours (or 2 days) before the test.
Pelvic Exam Versus Pap Test
Many people confuse pelvic exams with Pap tests. The pelvic exam may be a part of a woman's health care exam, and may be done even if a Pap and HPV test are not done. The pelvic exam alone will not find cervical cancer at an early stage, and cannot find abnormal cells of the cervix. Only Pap tests, or Pap plus HPV tests, can find early cervical cancers or precancers.