Learn more about HPV and cancer, which causes genital warts and can lead to some cancers .
HPV AND CERVICAL CANCER
HPV AND CERVICAL CANCER
Cervical cancer, also called cervical cancer, uterine cervix cancer or cervical cancer is the second most common cancer in women, second only to breast cancer.More than 90% of cervical malignancies are caused by HPV virus, a sexually transmitted infection by and currently preventable by vaccination route.
In this article we will talk about the relationship of HPV with cervical cancer.
WHAT IS HPV
The human papillomavirus, or human papillomavirus, known as HPV, is a virus that has more than 150 subtypes.The HPV virus only causes disease in humans, and is responsible for the appearance of common warts of the skin and genital warts, also called condyloma.In this text we will talk only of HPV related cervical cancer, if you want to learn about HPV and common and genital warts.
Although warts are a very common skin change, which makes HPV a serious health problem is its association with cervical cancer.Among the approximately 150 known subtypes, two of them are present in over 70% of cases of cervical cancer: HPV-16 and HPV-18.HPV is also associated with the occurrence of other cancers such as cancer of the penis, vagina, vulva and anus.
Importantly, when we speak of HPV linked to cancer of the cervix we are referring to a statistical risk.Being infected with HPV, mainly by two subtypes mentioned above, substantially increases the risk of developing uterine cancer but does not mean that the patient must develop a cancer.In fact, most women infected with HPV will not have cancer.
HPV is a virus transmitted through sexual contact and is actually the most common sexually transmitted disease in the world .It is estimated that up to 10% of the world population is infected with the virus and 50% of women (and men) have contact with it at some time in their lives.
HPV HAS NO CURE?
Most cases of HPV infection are asymptomatic and transient.After two years, 80-90% of patients are cured spontaneously, just by the action of your immune system.Therefore, for most women, HPV curable, and it occurs without any treatment.
Problems arise in the remaining 10 to 20% who can not get rid of HPV and develop permanent infection.These are patients who are at risk of developing cervical cancer.
Generally, it takes about 20 years of infection for the human papillomavirus can cause cervical cancer.For this reason, regular screening test with the gynecologist is important for early detection of malignant lesion signal in development (more on the Pap smear below).
ASSOCIATION BETWEEN HPV AND CERVICAL CANCER
There are 15 subtypes of HPV that are considered high risk for cancer of the cervix.However, as mentioned above, at least 70% of cancer cases are caused solely by HPV-16 and HPV-18 subtypes.The longer a woman remains infected with HPV, the greater the risk of it getting cancer.
Cigarette smoking increases the risk of cervical cancer caused by HPV, which is why every woman infected by the virus has proven yet another reason to quit smoking .
Another important risk factor is co-infection with HIV .The association between HIV and HPV not only further increases the risk of cervical cancer, as is often cause extremely aggressive tumors that spread rapidly through the body.
PAP TESTING AND DIAGNOSIS OF CERVICAL CANCER
The Pap test, also known as Pap smear, is currently the manner indicated for the screening of cervical cancer.
The Pap test is not meant to diagnose cancer, who makes the diagnosis is biopsy of the cervix.The Pap smear is just a screening test, that is, it only helps the doctor identify which women are at greater risk that need to be submitted to colposcopy and biopsy.
The Pap test is done during the pelvic exam with the help of a vaginal speculum (duck-billed).The gynecologist view the cervix and through a wooden spatula and a brush, crop material from the region.The collected material contains cells of the cervix, which are sent for microscopic evaluation to detect premalignant lesions and malignant lesions still in early stages.The collection of material also serves to carry out research of HPV and other infections such as chlamydia, gonorrhea, syphilis, Gardnerella, etc.
In general, it is recommended preventive examinations annually on all sexually active women.If the Pap identify cells with pre-malignant characteristics, the patient must be submitted to biopsy of the cervix.
WHAT IS CIN (CERVICAL INTRAEPITHELIAL NEOPLASIA)
The cervical intraepithelial neoplasia (CIN) is a premalignant lesion, which can be identified by biopsy of the uterine cervix.The NIC is not a cancer, but an injury to the cervical tissue at high risk of turning into one.Depending on factors such as size and location of the lesion and subtype of HPV type detected, cervical intraepithelial neoplasms are divided into three groups, in order of increasing risk of malignant transformation: CIN 1, CIN 2 and CIN 3.
Most cases of CIN 1 spontaneously heal in a period of up to two years, not needing more aggressive treatment.The cases of CIN 2 and CIN 3 also heal by themselves too often, however, as the risk of progression to cancer is higher, these injuries need to be addressed.
If the biopsy to detect the presence of a CIN 2 CIN 3 or injury, the most suitable is to make the area of excision which no pre-malignant changes of cells.Importantly, the excisions remove only the portion of the tissue with the risk of malignant transformation, but continue HPV present in the body.We remove only the region where the tissue is composed of cells that can, in the long term, turn into cancer.
If the biopsy to identify the presence of a cervical cancer of the uterus already established, it is necessary to carry out further tests, identifying the presence of metastases.Usually begins with a CT scan of the pelvis and abdomen.
In those people who develop permanent HPV infection, that is, the immune system is not able to eliminate viruses, there is no curative treatment available.These people are infected with the virus for life, being always at risk for malignant lesions, especially if they are HPV-16 or HPV-18.Therefore, the advent of the vaccine was an important step in the fight against cervical cancer, as this prevents contamination of people not yet infected.
There are two HPV vaccines: one includes the subtypes 6, 11, 16 and 18, and another 16 and 18. Therefore, the vaccine includes the main, but not all subtypes related to cervical cancer.This means that vaccination does not eliminate the need for annual Pap smear since it does not in 100% the risk of cancer.Vaccination is performed in three steps, the second and third doses 2 and 6 months after the first.
The vaccine has been shown from 9 years old and should preferably be offered to girls not sexually active.Remember that the vaccine is prevention rather than treatment of HPV.No use vaccinate those who have had contact with HPV.For this reason, vaccination in women over 26 years does not have the same protective effect, since many of the patients were already exposed to HPV during their lifetime.
Those in favor of vaccination in older women argue that even if the vaccine does not serve to combat existing HPV, it can protect against other subtypes that the patient may not yet have been exposed.
The vaccine is made with live attenuated virus, so it is quite safe.However, as there are still no studies proving its safety in pregnancy, it is not indicated in this group.
Be sure to also see this short video, produced by MD.Saúde team, explaining simply the HPV vaccination.