Blog Articles

Human Papillomavirus and Cervical Cancer

21 December 2020

1. What is HPV?

HPV (human papillomavirus) belongs to a group of viruses that infect the cervix. An HPV infection that does not disappear, meaning it becomes persistent, may increase the risk of developing cervical cancer.

There are over 100 types of HPV, of which about 40 can infect the genital tract and are sexually transmitted.

Genital HPV infections are usually asymptomatic and heal themselves spontaneously, in most cases. However, there are some HPV infections that can cause cervical cancer, other cancers and genital warts.

The types of HPV associated with cancer, are called oncogenic or high-risk types. There are 12 kinds of high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59) recognized by the International Agency for Research on Cancer (IARC).

An HPV infection is a necessary cause, although not sufficient, for the development of cervical cancer.

Many HPV infections are naturally resolved by the woman’s body, especially at a young age. However, about 5-10% of these infections may persist, which increases the risk of developing precancerous cervical lesions. If these lesions are not promptly detected and treated, they may progress to cervical cancer.

In Portugal, cervical cancer is the 3rd most common cancer among women. It has an incidence rate of around 12.2% and a mortality rate of around 3.6%.

Being informed about the persistence of some types of HPV can be crucial for the risk stratification of women who may develop cervical cancer.

As suggested by the new consensus for HPV infection and intraepithelial lesions of the cervix, vagina and vulva of the Portuguese Society of Gynecology of 2011 HPV testing is advised:

  • For women over 25;
  • After cytology with ASCUS results;
  • For postmenopausal women with LSIL cytology;
  • In post-colposcopic orientation (monitoring) in women referenced by cytology with AGC or ASC-H results.

4. What kind of results can I expect from HPV tests?

When testing for HPV we can determine:

  • The type(s) of HPV present in the body causing an infection;
  • If the infection is caused by HR (High-Risk) or LR (Low-Risk) types.

5. How important is it to know what type of HPV causes the infection?

Distinguishing whether an HPV infection is caused by a high-risk or low-risk type is useful to stratify the risk of a woman developing pre-cancerous lesions. To do this, there must be a persistent infection. To determine if an infection is persistent, we must know which type of HPV is causing it.

Information on mixed infections, which, depending on the types of HPV, influence the clinical outcome.

Post-treatment monitoring: HPV positivity in post-treatment helps predict possible recurrences of CIN2+ and CIN3+ lesions. This can only be achieved through tests that can determine the HPV type present in the lesion.

Monitoring the effectiveness of HPV vaccines (currently, there are HPV vaccines available for types 16, 18, 6 and 11).

6. Is knowing the type of HPV clinically relevant?

It is important to have an HPV test with sensitivity and clinically relevant specificities so that we can effectively detect HPV types in CIN2+ cases or in more severe situations.

Recent studies compared “CLART HPV” with other HPV tests. It was found that the “CLART HPV” has an excellent performance when compared with HC2 (a test with clinical cutoff setting) and it also enables us to detect various HPV types, in single or mixed infections, in a single test.