Tests are used to screen for different types of cancer.
Some screening tests are used because they have been shown to be helpful both in finding cancers early and in decreasing the chance of dying from these cancers. Other tests are used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.
Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection (finding cancer before it causes symptoms) decreases a person's chance of dying from the disease. For some types of cancer, the chance of recovery is better if the disease is found and treated at an early stage.
Clinical trials that study cancer screening methods are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site.
Studies show that screening for cervical cancer helps decrease the number of deaths from the disease.
Regular screening of women between the ages of 21 and 65 years with the Pap test decreases their chance of dying from cervical cancer.
A Pap test is commonly used to screen for cervical cancer.
A Pap test is a procedure to collect cells from the surface of the cervix and vagina. A piece of cotton, a brush, or a small wooden stick is used to gently scrape cells from the cervix and vagina. The cells are viewed under a microscope to find out if they are abnormal. This procedure is also called a Pap smear. A new method of collecting and viewing cells has been developed, in which the cells are placed into a liquid before being placed on a slide. It is not known if the new method will work better than the standard method to reduce the number of deaths from cervical cancer.
Pap test. A speculum is inserted into the vagina to widen it. Then, a brush is inserted into the vagina to collect cells from the cervix. The cells are checked under a microscope for signs of disease.
After certain positive Pap test results, an HPV test may be done.
An HPV test is a laboratory test that is used to check DNA or RNA for certain types of HPV infection. Cells are collected from the cervix and DNA or RNA from the cells is checked to find out if there is an infection caused by a type of human papillomavirus that is linked to cervical cancer. This test may be done using the sample of cells removed during a Pap test. This test may also be done if the results of a Pap test show certain abnormal cervical cells. When both the HPV test and Pap test are done using cells from the sample removed during a Pap test, it is called a Pap/HPV cotest.
An HPV test may be done with or without a Pap test to screen for cervical cancer.
Screening women aged 30 and older with both the Pap test and the HPV test every 5 years finds more cervical changes that can lead to cancer than screening with the Pap test alone. Screening with both the Pap test and the HPV test lowers the number of cases of cervical cancer.
An HPV DNA test may be used without a Pap test for cervical cancer screening in women aged 25 years and older.
Other screening tests are being studied in clinical trials.
Screening clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site.