Cervical cancer is one of the most preventable cancers today (source). A large percentage of cervical cancer cases are caused by the human papillomavirus (HPV).
The main goal of screening is to identify cancers at an early stage for treatment to be more successful. Another important goal of cervical cancer screening is to identify precancerous lesions (abnormalities or mutations in cells) caused by HPV, so that they can be removed to prevent cancer from developing.
Both HPV and Pap tests are essential parts of the Cervical Cancer Screening Process.
Pap tests check for abnormal growths or changes in the cells of the cervix. During a Pap test, a speculum is inserted to allow the medical professional to view the cervix and upper vagina. Thereafter, a brush or spatula is used to collect sample cells for further evaluation and laboratory tests.
If there are abnormal or alarming changes, additional tests such as colposcopy and other forms of biopsy tests will be performed. This precancerous condition where abnormal cell changes occur on the surface lining of the cervix is called cervical dysplasia. Women aged from 21 through 29 should be screened with a Pap test every three years.
HPV tests detect the presence of the HPV, a virus that can cause genital warts, abnormal cervical cells, and possibly cervical cancer. Specifically, HPV tests look out for any high-risk types of HPV commonly found in cervical cancer.
Presence of these high-risk types of HPV can possibly lead to cell changes that need to be treated in time before cervical cancer occurs. HPV 16 and HPV 18 in particular are responsible for about 70% of cervical cancers worldwide (source). By testing for these HPV types, medical professionals would be able to assess the risks and take steps to prevent cervical cancer from developing.
Types of tests for different age groups
Women aged 30 and above are recommended to go for either a HPV-only test or HPV/Pap co-testing every five years (source).
Both HPV/Pap co-testing and HPV-only tests are more sensitive than Pap tests alone. The longer interval (compared with three years for women younger than 30 years old taking Pap tests only) allows abnormalities to be detected in time while reducing the detection of HPV infections that would have been successfully controlled by the immune system.
Both HPV/Pap co-testing and HPV-only tests may also improve the detection of glandular cell abnormalities, which are less common but also cancer-causing. Pap tests are not as good at detecting such glandular cell abnormalities. Both tests are usually done at the same time and involve gathering a sample of cells from the cervix.