Human papillomavirus (HPV)

This is a frequently transmitted disease and in most cases it does not result in any pathology. It can, however, release a benign disease in the form of warts, or less commonly, different types of cancer. In women, HPV can cause cervical cancer.

What is HPV?

HPV is spread via direct skin to skin contact during sex, and not through fluids. In around 90% of cases it disappears spontaneously, but it can be transmitted whilst the virus is present.

HPV is classified in terms of whether or not there is a risk of cancer developing:

• Low risk: may cause benign genital warts or condyloma.
• High risk: up to 14 different types of high risk or congenital HPV have been described, of which the most common are types 16 and 18. These are responsible for 70% of cancers caused by this virus.

It should be said that it is possible to be infected with more than one type of HPV. In addition, persistent infection can result in developing cancer of the cervix, vulva, penis, anus or oropharynx.

Specifically, the virus initiates dysplastic changes in the epithelial cells which continue to evolve until they produce an invasive cancer. This is a progressive process and the time from infection until developing the disease can be up to twenty years.

Symptoms

Genital warts or small protuberances or groups of different sizes and shapes may appear in the area of the genitals.

In the case of cancer, there are no symptoms until it is very advanced. In the case of cervical cancer, symptoms show up as:

• Abnormal vaginal bleeding
• Pain in the lower abdomen, pelvis, back and legs
• Weight loss
• Pain during sexual intercourse

Who is affected by HPV?

In Catalonia, cancer of the womb occurs in 7.2 out of every 100,000 women per year (2003-2007). This represents 2.8% of all female cancers. Between the ages of 35-64 this figure rises to 16.1 cases for every 100,000 women. Furthermore, the risk of developing this disease for women who live to 75 is one in 106. 

Anal cancer has an annual incidence rate of 1.8 cases for every 100,000 people, but in the case of men engaging in same-sex relations and infected with HIV, this rises to 70 or 128 cases for every 100,000.

Diagnosis

When there is evidence of warts, diagnosis is usually clinical or by biopsy. Cancer is detected by cytology tests, which allow anomalous changes in the cells to be seen before they develop. If the test comes back anomalous it can be complemented by a colposcopy that allows magnified examination of the cervix and samples to be taken.

HPV detection is the main component of a preventative strategy to detect the virus before it reaches the point of disease.

Typical treatment

There is no specific antiviral treatment for HPV.

In the case of warts, in most cases they can be eliminated through surgery, ointments or other treatments.

If cancer does develop, treatment will depend on the stage at which it is diagnosed. For example, if it is detected early in the cervix this can involve removing the damaged tissue, whilst in more advanced stages it may require a hysterectomy, radiotherapy or chemotherapy.

Prevention

The use of condoms is essential to prevent HPV. There is also highly effective vaccine used as a way to prevent cervical cancer. Regular cervical smear tests (Papanicolau test) are also carried out as a form of screening. This strategy, however, is changing due to the techniques used to detect the virus which, together with the smear test, are enabling the different stages of the disease to be monitored (acquisition, persistence, progression to precancerous lesions and invasion).