The Papillomavirus it is the second pathogen responsible for cancer in the world. Although the majority of infections regress spontaneously, in case of persistence and chronicity, the infection can evolve over time into precancerous lesions and cancer.
This is why we focus a lot on vaccination, which represents the most important weapon to defeat cancers caused by HPV, including cervical cancer, also called cervical cancer. Currently, the nonavalent vaccine, in addition to HPV 6, 11, 16 and 18, ensures protection against five other strains capable of inducing cancer, preventing over 90 percent of the tumor forms associated with the virus.
What risks exist and how much the vaccine can help
Let’s look at the recent data. Every year in our country almost 6,500 cases of cancer are attributable to HPV: 2,365 in the uterine cervix, 1,900 in the oropharynx, 1,200 in the vulva, 500 in the penis, 300 in the anus and 200 in the vagina.
These figures are enough to highlight the importance of the protection that a vaccine that is intended for and offered to very young people can offer. The prevalence of the infection is highest in women between 20 and 24 years old. The best known HPV cancer is cervical cancer, the fifth most frequent cancer in under 50s.
Through vaccination it is possible to interrupt at the source the chain that leads from infection to cancer and its extension to men allows the female population to be better protected as well as the male population.
Prophylaxis is also recommended in women aged 25 and over, using for the occasion the appointment with the first Pap Test. In fact, it is important to increase not only vaccination rates, but also the levels of adherence to screening against cervical cancer. Depending on the program, the Pap test should be performed every three years starting from the age of 25 or the HPV test every 5 years from the age of 30-35.
The relationship between viruses and cervical cancer
Papillomavirus infection is the most frequent sexually transmitted infection. It is estimated that four out of five people are infected with the virus in their lifetime, both men and women, and the absence of symptoms favors its spread.
In approximately 80% of cases, the HPV infection occurs asymptomatically, because the body has the ability to eliminate the virus. In other cases, the immune system fails to defeat it, with serious consequences such as cancer.
Generally, the time between the infection and the onset of precancerous lesions is approximately 5 years, while the latency for the onset of the cervical cancer it can be decades. Cervical cancer, closely related to HPV virus infection, occurs mainly in the age range from 35 to 55-60 years.
How the infection leads to the tumor
The highest incidence of new viral infections, a necessary condition for the development of the cancerous form, is concentrated in young men and women. But in any case, even if the first infection almost always occurs among very young people, in fact, in subsequent years new infections can occur which lead to an increased risk of developing cancer.
The reason? The virus does not naturally induce the immunological “memory” that can instead be obtained thanks to the vaccine. In particular the cervical cancer it develops from cellular lesions induced by papilloma virus infection. Over time, these alterations in cellular DNA tend to affect an ever-increasing number of cells, initially causing an intraepithelial neoplasm (i.e. localized exclusively in the cells that constitute the outermost part of the mucosal wall of the uterus) of low grade (CIN I or mild dysplasia) which tends to evolve into medium-grade intraepithelial neoplasia (CIN II or moderate dysplasia) and of high grade (CIN III or severe dysplasia).
This last level, i.e. the severe dysplasia (a condition characterized by profound modifications of the cellular genome, which has already taken on tumor characteristics), can be considered in the same way as the so-called carcinoma in situ, in practice a localized tumor. The advance of the tumor subsequently leads to preclinical invasive carcinomathat is, not identifiable thanks to the symptoms reported by the woman alone and, finally, to invasive carcinoma. The progression time from lesions located exclusively in epithelial cells to invasive forms can be extremely long (10 to 20 years), although it is possible that initial lesions transform into invasive forms in short periods of time.
The Papilloma Virus
The Papilloma Virus, or HPV (acronym for Human Papillomavirus), is a very widespread virus, which almost always causes a completely asymptomatic viral infection destined to go unnoticed, without causing consequences.
They know each other over 100 types of human papillomaviruses, most of which cause minor diseases, such as, for example, skin warts. HPV transmission occurs mainly through sexual intercourse.
Fortunately, in most cases the body gets rid of it spontaneously within a few months without any danger to future health. The papilloma virus is in fact a sneaky enemy: it can affect around eighty percent of sexually active people even without their knowledge, because it does not create symptoms and the immune system can get rid of it naturally. But this does not always occur and in more or less twenty percent of cases the “enemy” persists and can develop cellular alterations over the years that can lead to neoplastic lesions.
