Human papillomaviruses (HPV for short) are DNA viruses of which over 200 types are known and 124 virus types are more precisely defined. They can be responsible for cell growth in abnormal areas, precancerous lesions, as well as cancer or genital warts.
Of the known types, 30 virus types can be found in the anus and genital area, and 14 virus types are known to be oncoviruses, i.e. they can trigger cancer.
Classification of human papillomaviruses:
Those virus types that can be found in the genital area are classified according to the risk of cancer.
- Low-risk viruses: These include HPV 6, 11, 40, 42, 43, 44, 54, 61, 70, 72, 81 and CP6108. HPV 6 and 11 are known causes of condylomata acuminata (genital or genital warts), but do not cause life-threatening diseases.
- High-risk viruses:
High-risk viruses include HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73 and 82.
Most people with cervical cancer have at least one human papillomavirus from the high-risk category.
There is also a direct connection with HPV in some other carcinomas in the genital and anal area and also in carcinomas in the area of the mouth. - Possible high risk viruses
HPV 26, 53 and 66 are among those viruses that cannot be clearly assigned, but which suggest that they also belong to the high risk group. - HPV genotypes of undetermined risk
These viruses cannot be assigned to a risk group because they have not yet been researched enough to know whether they pose a high or low risk.
Since 2005, the International Agency for Research on Cancer (IARC) has listed human papillomaviruses 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 66 offiecell as carcinogenic.
What cancers can be caused by human papillomaviruses?
Many people are under the misconception that only women are at risk from human papillomaviruses because they only cause cervical cancer.
This false information can have serious and even life-threatening consequences, because men can also be affected.
Men can not only be carriers of HPV and pass it on, but can also fall ill with tumours that are triggered by HPV. Men can also be affected by genital or anal tumours, as well as carcinomas of the mouth and throat.
Cervical carcinoma:
Cervical carcinoma (cancer of the cervix) is the best-known cancer that can be traced back to infection with the human papillomavirus. Approximately 97% of tumour formations are attributed to the virus, with the sufferers most frequently infected with HPV 16 and 18.
Penile carcinoma:
This is a squamous cell carcinoma which affects the male genital area. Here, too, HPV 16 and 18 are found in many cases, which suggests a connection between the cancerous disease and the human papillomavirus.
Anal tumours:
Tumours in the anal region occur extremely rarely, but here too human papilloma viruses can be detected and suspected as the causative agent
Oropharyngeal carcinomas:
These tumours occur in the area of the soft palate, base of the tongue and palatine tonsils. Human papilloma viruses can be detected in about 20 % of the patients. However, whether these viruses also have a carcinogenic effect in this context has not been clearly clarified
Vulvar tumour:
Another very rare disease is carcinoma of the female vulva. The disease often occurs together with cervical cancer. As with cervical carcinoma, HPV 16 and 18 are most commonly found. The HPV infected cells settle in the mucous membrane of the anus and genital area and spread to the cervix, where they cause cancer. In addition, the disease can occur in the external genital area and anus.
How does a human papilloma virus cause cancer?
A human papilloma virus attaches itself to the skin and mucous membranes. Normally, it disappears again after about 2 weeks without causing any symptoms. However, it can also happen that the virus settles in the cells and spreads more and more, not only to the outer skin cells, but also, for example, to the inner genital organs, e.g. the cervix. Once the virus has taken hold, it triggers abnormal cell growth, which can develop into a carcinoma if it is not detected and removed early. This process from infection with HPV to cancer formation can take up to 15 years on average.
Infection with HPV
Infection with human papilloma viruses is direct, i.e. from person to person. If a person has microscopic injuries on the skin and mucous membranes, the virus can penetrate there and infect the epithelial cells.
The viruses are most frequently transmitted during sexual intercourse, both during anal and genital intercourse and during oral sex. A condom does not provide 100% protection, as close skin contact can also lead to transmission.
Preventive measure:
To prevent HPV infection, there is a vaccination that is almost 100% effective. The vaccination is recommended for girls and boys aged 9-14 years. The reason for the recommendation at a young age is that the vaccination should be completed before the first sexual contact.
Even though men have a lower risk of suffering from cancers caused by HPV, it makes sense to vaccinate boys as well, since they can carry human papilloma viruses and also pass them on. If they protect themselves against these viruses, they also protect their future partner.
Do you notice an HPV infection?
The simple answer is: No!
If you are infected with a human papilloma virus, you will not have any symptoms. Human papilloma viruses come and go silently. You get infected undetected and in most cases such an undetected infection is cured in about 2 weeks. In some cases, however, the viruses can take hold, multiply without any warning and be responsible for abnormal cell growth and even cancer.
Prevention is better than cure.
Since an HPV infection is silent, it is extremely important to have regular check-ups, especially with regard to cancer. Make use of regular preventive examinations in order to detect possible abnormal cell growth at an early stage.