Cervical Cancer –
The disease – cancer of the mouth of the uterus is a dreadful disease. Like most cancers it does not cause any pain while developing and thus often gets detected late. Treatment then involves radiation and extensive surgery- causing morbidity and mortality. This is especially the case where women are not routinely screened by PAP smears – like in our country. It is the most common cancer in women in India: ~150,000 new cases/year. Globally- cervical cancer is the second most cancer among women: ~500,000 new cases and 270,000 deaths/year.
Till recently our fight against this cancer was in the form of secondary prevention- that is, screening by PAP smears for early detection and management of pre-cancerous lesions when detected. Today we also have a vaccine as a primary prevention tool. This vaccine is against the causative agent – a virus.
Causative Agent – Human Papilloma Virus ( HPV)- is the cause of virtually all cases of cervical cancer. It is a DNA tumor virus, and there have been more than 100 types of HPV identified. Out of these 15 to 18 of these types have been found to be associated with cancer. Of these high-risk HPV types, types 16 and 18 are the most clinically important, because they are associated with approximately 70% of cases of cervical cancer. (Low-risk types like HPV 6 and 11 are associated with approximately 90% to 95% of cases of genital warts).
The virus is transmitted through sexual contact .Considering the fact that it is a skin-to-skin virus rather than a body fluid virus; it is hard to completely protect against transmitting this virus . Current estimates are that 80% of sexually active adults will have acquired an HPV infection some time in their life by the time that they are age 50.
The good news is vast majority of HPV infections will resolve on their own; this is referred to as HPV clearance. Within 2 years, approximately 80% to 90% of infections resolve completely.
HPV persistence (infections which do not resolve) -is one of the major risk factors for developing cancer.
Part 2 of the article will contain details about the Vaccine against Cervical Cancer.