Monday, September 26, 2011

HPV - Cervical Cancer Causes

Cervical cancer is caused by persistent infection of human papillomavirus (HPV) oncogenic types (which could potentially lead to cancer). It has been proved that HPV is the absolute cause of cervical cancer - the prevalence rate in the world of cervical carcinoma was 99.7% *.

What is HPV? 
HPV is a very common virus. This virus-based DNA and genetically stable. This means the genetic stability of viral infection can be prevented through vaccination in the long term, unlike the influenza virus RNA-based, for example, are often changed and thus require regular vaccinations.

Oncogenic HPV and low-risk HPV
Every woman is at risk of oncogenic HPV infection, which can cause cervical cancer. Approximately 100 types have been identified. Forty-type attacks the genital area. Of the 40 type, 15 is an oncogenic type and can cause cervical cancer or precancerous lesions on the cervix surface .***

Globally, HPV type 16 together with the type 18 can cause 70% of all cervical cancer incidence. In addition, type 45 and 31 occupy the third and fourth types of HPV cause cervical cancer, while types 16,18,45 and 31 together are responsible for 80% incidence of cervical cancer worldwide .*

Transmission of HPV
Every woman is at risk of oncogenic HPV infection that can cause cervical cancer .**
HPV can be easily transmitted through sexual activity though the transmission does not depend on the existence of penetration but simply through the touch of the genital region skin (skin to skin genital contact).*

Thus every sexually active woman is at risk for cervical cancer. It is estimated that 50-80% of women may be exposed to HPV infection throughout their lives and 50% of these infections is oncogenic type .**

Towards the development of HPV Cervical Cancer HPV infection does not always develop into cervical cancer. Most HPV infections (between 50-70%) disappeared through natural immune response, after a period of several months to two years .*** However, cervical cancer can develop when an infection caused by oncogenic HPV types do not disappear.*

In a broad sense, it is estimated that of every one million women infected with oncogenic HPV types, almost 10% (100,000) will be pre-cancerous changes in cervical cells (cervical dysplasia). Of that number, about 8% (8000) would have precancerous changes in cells - cells found on the surface of cervical (carcinoma in situ), of that number, 20% (1,600) will continue to develop into cervical cancer if left .*

The development of oncogenic HPV infection to cervical cancer can occur when there is a persistent infection of some cells contained in the cervix (flat or oval epithelial cells in the cervical transformation zone). Cells - these cells are very susceptible to HPV infection and when infected, will double, growing beyond reasonable limits and loses its ability to correct genetic abnormalities.

This will change the arrangement of cells in the cervix. HPV virus will mix with a warning system that triggers an immune response that should destroy the abnormal cells are infected by the virus. The development of abnormal cells in cervical epithelium may develop into pre-cancer called cervical intraepithelial neoplasia as well as (CIN).

If notice of persistent oncogenic HPV infection is found three major patterns in pre-cancerous, starting with infection of the cells and the development of cells - abnormal cells that may progress to intraepithelial neoplasia and eventually become cervical cancer.

Detection of HPV 
Genital HPV infection can be recognized SCARA diarea but can be diagnosed clinically with certainty through method - molecular detection methods.

As well as the immunology of HPV 
The key to the development of cervical cancer is persistent infection (persistent) of the type - the persistence of oncogenic HPV types is an opportunity for the occurrence of malignancy (cancer). It is estimated that HPV oncoprotein mixes with the natural immune response and programmed cell death, cell growth rate to be increased, and the cell - the infected epithelial cells become more susceptible to secondary triggering factors that can damage cells and progress to cancer .*

If a woman has been infected by HPV, not necessarily going to make a woman immune to subsequent infection .**

The vaccine will make the immune system to recognize and neutralize the virus at once the virus enters the body through acquired immunity.

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