An article published in the May 10th New England Journal of Medicine showed that young women not infected with Human Papilloma Virus HPV 16 and 18 who were vaccinated with the Gardasil vaccine had a lower occurrence of the high grade precancerous diseases on the cervix than those who were vaccinated with placebo.
The study was done on 12,167 women aged 15-26 years who had not been previously infected with the HPV. Thus the vaccine, if given to young women who have not already been exposed to the Human Papilloma Virus, is effective in preventing cervical dysplasia in women that will be apparent within years rather than decades.
"Human papillomavirus types 16 (HPV-16) and 18 (HPV-18) cause approximately 70% of cervical cancers worldwide,"
Laura A. Koutsky, PhD, from the University of Washington in Seattle, and colleagues from the FUTURE II study group.
Reference:N Engl J Med. 2007;356:1915-1917.
2 comments:
To summarize this published medical journal article:
1. In the FUTURE I trial, GARDASIL demonstrated no clinical efficacy among the general subject population for overall reduction in the rates of grade 2 and grade 3 cervical intraepithelial neoplasia and adenocarcinoma -- the only recognized precursors to cervical cancer.
2. In the larger FUTURE II trial, GARDASIL demonstrated no clinical efficacy among the general subject population for overall reduction in the rates of grade 3 cervical intraepithelial neoplasia and adenocarcinoma -- the strongest (and many would argue only valid) precursors to cervical cancer.
3. Extrapolating from GARDASIL's very limited clinical "success" (in the FUTURE II study only) against grade 2 cervical dysplasias (40% of which regress spontaneously), 129 women would be have to be vaccinated (at a cost of about $60,000) to prevent a single grade 2 cervical dysplasia.
4. GARDASIL's protection against cancer associated HPV strains 16 and 18 appears to cause a disproportionate increase in of pre-cancerous dysplasias associated with other HPV strains associated with cervical cancer "raising the possibility that other oncogenic HPV types eventually filled the biologic niche left behind after the elimination of HPV types 16 and 18."
5. Even if you segregate out the women who hadn't been previously exposed to either HPV 16 or 18, we are talking about just a 17% decrease in all high grade dysplasias (266 out of 6080 vs. 219 out of 6087) -- many of which would spontaneously regress without treatment. So we would have vaccinate 129 women (at about $500 for the three shot regimen) to avoid a single, eminently treatable dysplasia. That's about $60,000 per dysplasia prevented.
This is all directly from the article linked above.
I myself would add that we currently have only 3 years of follow up to go on in terms of both GARDASIL's safety and efficacy among the 16 to 26 year female population, no data concerning its efficacy among 9 to 12 year old girls and only 18 months of follow up on less than 600 total preteen girls in terms of safety data about GARDASIL within its targeted population.
Thank you for your comments. I aggree with your thoughts.
I recently had a patient show up in the emergency room in our local hospital who had no insurance and hence had no screening for cervical dysplasia. She had advanced cervical cancer. She died within 6 months. No amount of money can replace this woman's life.
I realise the vaccine is new, expensive and the efficacy data is not set in concrete. However, it is a great step in the right direction especially for the population that don't take advantage of the preventive screening. The third world may benefit even more than the developed world especially when more drug companies get involved and the price of the drug gets cheaper.
With time, as other vaccines enter the market the cost would come down. " A Journey of a thousand miles begins with the first step."
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