A little more about HUMAN PAPILLOMA VIRUS AND CANCER:
--------------------------------------------------------------------------
HPV, the most sexually transmitted disease, has been implicated in:
- Cervical cancer
- Head and neck cancer
- Anal and most vaginal  Cancers, penile cancers
- the role in lung and Esophageal cancers is not clear.
With over 130 types, only few have been implicated with cancer .  (HPV16, 18 being the most cited since the work by Durst and Boshart)
90 % of infected people will see their infection cleared.
10 % will develop chronic infection.  and by year 30 after original infection, 50% of the 10% will develop eventually a malignancy.  It is widely believed that in those who developed the disease, the HPV gene E6 and E7 and their proteins products have managed to inactivate suppressor genes such as P53 and RB1 as part of the mechanism to cancerous transformation with loss of regulation of  cellular proliferation, and control of chromosome instability. This process led to immortalization of Keratinocytes in the laboratory.

In the Oropharyngeal cancers, the verrucous squamous subtype is the most associated  with HPV.  HPV positive tumor however has a higher response rate with a better 2 year progression free disease.
Most of these cancers can be avoided by HPV immunization.  The HPV presence can be confirmed by in-situ Hybridization.   Expression of the P16 type appear to correlate with less P53 and RB1 inactivation and therefore leads to best prognosis whereas EGFR over expression tends to suggest a poorer outcome.