Cervical cancer screening methods
There are three common cervical cancer screening paradigms in the US
A molecular test that detects for either HPV DNA or HPV mRNA; only some HPV tests are approved by the FDA as HPV primary tests2,3
Also known as Pap smear or smear test this is the traditional method for screening; it utilizes cytology to look for abnormal cells in the cervix that can lead to cancer2,4
All three screening methods can find cervical cancer precursors before they become cancer, but HPV tests are more accurate and reliable than Pap tests4
Learn more with Dr. Lee Shulman and Dr. Anna-Barbara Moscicki on the recent guidelines, the range of cervical cancer screening tests, and the impact on risk stratification and patient management.
Comparing the three screening paradigms:
PAP TEST
Has a lower sensitivity as compared to HPV tests, this means that Pap tests may miss some precancers and also need to be repeated frequently4
HPV TEST
Is more accurate and reliable than Pap tests; they can also rule out disease and therefore do not require frequent repetition4
The World Health Organization (WHO) recommends using HPV DNA detection as the primary screening method2
CO-TEST
Similar performance as HPV testing,3 but less efficient and more costly - as it requires two tests. Co-testing also detects very minor changes that have a low risk of turning into cancer and can therefore lead to unnecessary colposcopy referrals4
The American Cancer Society (ACS) and the World Health Organization (WHO) recommend HPV testing as the preferred screening method2,4
ACS, American Cancer Society; ASC-US, Atypical Squamous Cells of Undetermined Significance; DNA, Deoxyribonucleic acid;
FDA, Food and Drug Administration; HPV, human papillomavirus; hr, high-risk; Pap test, Papanicolaou test; US, United States; WHO, World Health Organization
1. ACS’s Updated Cervical Cancer Screening Guidelines Explained. NIH. 2020. Accessed 3 Nov 2021.
2. WHO guideline for screening and treatment of cervical pre-cancer lesions for cervical cancer prevention. WHO. 2020. Accessed 3 Nov 2021.
3. Perkins RB et al. J Low Genit Tract Dis. 2020;24(2):102-131.
4. ACS’s Updated Cervical Cancer Screening Guidelines Explained. NIH. 2020. Accessed 3 Nov 2021.
What are CIN 1, CIN 2 and CIN 3?
CIN is graded by how deep the cell changes go into the surface of the cervix. It is graded into: CIN 1, CIN 2 & CIN 3.1
CIN 1
Surface layer of the cervix cells
CIN 1 means one third of the thickness of the surface layer is affected.
Cells showing CIN 1 will often return to normal without any treatment. Recommendations are to prescribe further cervical screening tests or colposcopies to check whether your patients’ cells have improved. If these tests show the CIN 1 is not improving, you may recommend treatment.
CIN 1 is also called low-grade squamous intraepithelial lesions (LSIL)2
CIN 2
Surface layer of the cervix cells
CIN 2 means two thirds of the thickness of the surface layer is affected.
CIN 2 has a risk of developing into cervical cancer.
CIN 2/3 is also called high-grade squamous intraepithelial lesions (HSIL) and it is a precancerous condition2
CIN 3
Surface layer of the cervix cells
CIN 3 means the full thickness of the surface layer is affected.
CIN 3 is also known as carcinoma-in-situ.
CIN 3 has a higher risk of developing into cervical cancer.
CIN 2/3 is also called high-grade squamous intraepithelial lesions (HSIL) and it is a precancerous condition2
Sensitivity, specificity, negative predictive value & positive predictive value
Sensitivity:
the ability of a screening test to correctly identify all people with the condition from a group of people who are known to have the condition, aka the ability to detect a true positive
Specificity:
the ability of a screening test to correctly identify all people without the condition from a group of people who are known to not have the condition, aka the ability to detect a true negative
False positive:
A positive test result for someone who does not have the condition
False negative:
A negative test result for someone who has the condition
Trevethan R. Front Public Health. 2017;5:307.