Understanding HPV tests
A variety of HPV tests can be used to detect HPV genotypes and determine a woman’s risk of developing cervical precancer and cancer. Current FDA approved HPV tests can be divided into two categories: assays with partial genotyping & assays with extended genotyping.1,2
- HPV assays with partial genotyping report HPV 16 and 18 or 18/45 separately and the remaining high-risk genotypes in a single, pooled result3
- HPV assays with extended genotyping detect and report at least 5 individual high-risk HPV genotypes1-6
There are 14 most clinically relevant hr-HPV genotypes, and partial genotyping reports many of these genotypes in a single result with a pooled group.1,2
| HPV Genotype | HPV Test result 1 | |
|---|---|---|
| HPV 16 | Negative | |
| HPV 18, 45 | Negative | |
| HPV 31, 33, 35, 39, 51, 52, |
Positive |
With partial genotyping, a positive result for the pooled group could indicate infection with HPV 31, which has a similar risk of developing into cervical cancer as HPV 18,1,2,6-10 or it could mean an infection with HPV 51, which has a much lower risk of developing into cervical cancer.7
Partial genotyping can mask the true risk of cervical precancer and cancer and prevent effective monitoring of HPV infections1
FDA, Food and Drug Administration; HPV, human papillomavirus; hr, high-risk
1. Bonde JH et al. J Low Genit Tract Dis. 2020;24(1):1-13
2. Salazar KL et al. J Am Soc Cytopathol. 2019;8(5):284-292
3. Bonde J et al. J Clin Virol. 2018;108:64-71
4. Brady MT et al. Pediatrics. 2012;129(3):602-5
5. Meites E et al. CDC, Human Papillomavirus. Accessed 4 Nov 2021.
6. Perkins RB et al. J Low Genit Tract Dis. 2020;24(2):102-131
7. Stoler MH et al. Gynecologic Oncology. 2019;153(1):26–33
8. Monsonego J et al. Gynecol Oncol. 2015;137(1):47-54
9. Schiffman M et al. Gynecol Oncol. 2015; 138(3):573–578
10. Schiffman M et al. Int. J. Cancer. 2016;139(11):2606–2615
11. Schiffman M et al. J Clin Microbiol.2015;53(1):52-9
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.