Cervical cancer or cervical cancer, the second most common type of cancer in women worldwide after breast cancer, is to blame for 900 deaths in Spain, where about the year 2000 are made diagnoses.
One of the most important discoveries in the investigation of the etiology of cancer in the last 25 years has been the demonstration that cervical cancer is caused by infection with human papilloma virus (HPV). And, although most HPV infections carry a benign course and resolve spontaneously, scientific evidence has described the cervical cancer is a sequel to long-term persistent infection by certain genotypes of HPV.
In this regard, experts have noted that the association between human papillomavirus and cervical cancer is greater than the association between smoking and lung cancer. However, it is necessary persistence of the disease to develop invasive cervical cancer. In addition, a number of co-factors that can help your persistence and carcinogenic progression, smoking and immunosuppression (HIV infection and immunosuppressive therapy in transplant recipients) are important risk factors.
The identification of the viral origin of cervical cancer, as well as the main elements of its natural history and its pathogenesis have opened new options for secondary prevention (early detection of preinvasive cervical cytology) and provide, for the first time in oncology, primary prevention options, such as vaccination.
An unknown infection
HPV is a sexually transmitted virus, but not required any penetration as they can be spread by simple contact. In fact, 75 percent of women have HPV infection at some point in their lives, usually soon after the onset of sexual activity. In Spain, it is estimated that between 700,000 and 1.4 million women are infected with this virus.
The main problem is that most of those infected are unaware that it is acting transmitter and increasing infection rates. The infection may suffer any person who has sexual relations without protection, both men and women. Added to this is that the virus can be idle for up to 20 years, which may not always correlate with dysplasia recent sexual contact.
This virus is composed of a group of infectious agents with more than 100 subtypes known so far. Each is recognized by a number and are classified according to the place of the body where injuries occur. It is estimated that there are 30 subtypes of human papillomavirus is sexually transmitted.
The most common are 6 and 11, which cause benign warts or warty formations on the Triactol external genitals, and 16 and 18 associated with genital carcinomas. Although most HIV infections are transient and disappear within 2 years if the virus causing the papilloma virus infection is a high-grade or high viral load present, there is a greater likelihood of persistence.
Prevention awareness
Given this context, experts stress the importance of the public awareness of preventive measures against the spread of HPV, mainly through the use of condoms, and avoiding contact with genital areas not covered it, making revisions and avoiding promiscuity.
However, also note that various factors have encouraged the spread of this virus in Spain, among which is the change in sexual habits of Spanish women who have advanced the age at first sexual intercourse (from 22 to 18 years) and thus the number of sexual partners on average throughout his life, and the arrival of immigrants.
On the other hand, the secondary prevention of cervical cancer through early detection of preinvasive cervical lesions are considered critical to disease control. The test performed is the Pap smear or Pap test, which detects cellular alterations. There is also a specific analysis that detects the DNA of the papilloma virus.
Organized screening programs have proven effective population in countries where there have been, but there are factors that determine their effectiveness, such as tumor incidence, natural history of the disease, difficulties in reaching those at greatest risk this type of cancer and the sensitivity of cytology.
Preventive coverage in Spain
In the case of Spain, recently published the results of Aphrodite, more work on this aspect shows in Spain (were obtained through surveys of 9852 women between 18 and 70 of 17 regions), and has been the first to assess the coverage of Pap smear nationwide.
The study results reveal that the use of vaginal cytology in Spain is high, although some populations are not made so many tests as is recommended. This study also assessed the coverage of screening for cervical cancer using Pap test at the level of the entire Spanish territory. According to the data, 72 percent of women ignores the value of screening in the prevention of gynecologic cancer cervix, and 20 percent of women of childbearing age have never had a Pap smear.
The study’s authors criticize Aphrodite also in Spain the implementation strategy of smear does not follow a line organized, which means that young women with financial resources and low risk are more controlled than older women, with fewer resources and a much higher rate, which are ultimately those most in need. Moreover, autonomous regions, Madrid, La Rioja and Asturias have a wider coverage of screening for cervical cancer. At the other extreme, Extremadura, Andalusia and Castile-La Mancha.
In addition, being older than 55 years, living in a rural area and belong to low social classes influences the time to move gynecological exams. Thus, the percentage who have made a cytology increases progressively to 55 years, and from here, decreases rapidly. In addition, 61.1 percent of women in towns with fewer than 5,000 residents have a Pap ever versus 77.6 percent of municipalities with more than 200,000 inhabitants.
Also, nearly 60 percent of women in lower social classes have ever done Pap test compared with 83 percent of respondents with a higher social status. There are also contrasts in terms of frequency: only 41 percent of respondents had tested less than a year ago, 69 percent had done in the last three years and 73 percent in the past five years.
With regard to knowledge about the relationship between HPV and cervical cancer, 41 percent of women surveyed believed that this type of cancer is hereditary and almost half do not know the human papilloma virus and its mechanism of action, although they have exposed almost 80 percent of sexually active women. In addition, 20 percent think that the main factor for the disease is linked to age.
Vaccines: the beginning of the end?
Given this situation, experts will highlight the value that the quadrivalent vaccine against human papilloma virus effective against the four virus types 6, 11, 16 and 18, responsible for the majority of HPV-related diseases, such as cervical cancer, vaginal, vulvar and anal sex.
He notes that this preventive vaccine is designed to create antibodies that favor humoral immune response in uninfected individuals, which can enable rapid and effective in controlling HPV if the person ever comes into contact with this virus. The vaccine will be available soon in our country, as it is in virtually all other European Union countries.
According to the data used, the introduction of the vaccine in Spain, which is administered before the onset of sexual intercourse, around 12 or 13 years, achieve a significant reduction in disease burden Provided that vaccination coverage above 80 percent. These data are consistent with other studies worldwide.
In addition, currently being undertaken by the development of new preventive vaccines not only against HPV infection, but treatment in the sense of preventing the occurrence of injuries can bring on cancer in people already infected.