Natural History HPV Immunogeneral For Cancers Part II
A women who is negative for high risk HPV has a negligible risk of developing cervical cancer.
There is conflicting evidence whether high risk HPV strains persistent longer than others in the absence of developing precancerous lesions.
HIV infection increases the risk of HPV persistence in all ages.
There is a slight increase in HPV infections in some women who are 50 + years of age.
The long-term persistence of high risk carcinogenic type HPV without the development of cervical precancers is low.
The majority of high-risk HPV positive infections clear. The majority of women who have high-risk HPV infections do not develop cancer.
Cervical infections of minor cytologic abnormalities (ASCUS= atypical squamous cells of undetermined significance or LSIL= low-grade squamous intraepithelial lesion) usually clear within a few months or years.
The best established etiologic co-factors for invasive cancer among HPV-infected women are smoking, long term hormonal contraceptive use, multiparity, and HIV infection.
The most common determinants of risks in HPV infected are women with persistence of infection and being positive for HPV 16.
Smoking and oral contraceptives most likely support viral persistence.
The HPV infects cervical transformation zone (TZ), followed by a viral persistence rather than clearance, progression of the persistently infected epithelium cervical precancer and ultimately invasion.
The peak rate of HPV infection in women is in women under 25 years of age and then it declines and plateaus around 30-35 years.
The known behavioral co-factors such as smoking, ________ to determine whether a women develops cervical precancer and eventually cervical cancer are less important then the strain of HPV. Condom use is partially protective for initial infections but it is level in clearance of persistent infections is not clear. Non-Viral Co-Factors for HPV Persistence in Diagnosis of CIN 3+.
The role of C-trachomitis” infection is a co-factor persistence in CIN3+ is controversial. A recent study did not find an association between C-trachomitis and CIN2+ lesions.
Lack of an adequate immune response is the strongest factor resulting in the persistence of HPV infection.
The transformation zone (TZ) is where there is transition of squamous cell to columnar cells.
50% of infections clear up in six months and in a great majority over 90% clear within several years.