A prostatecancer vaccine that the US Food and Drug Administration rejected in2007 has now won the regulator's approval, making it the first cancer vaccine to do so, according to newscientist.com. Made by Dendreon of Seattle, Provenge does not prevent or cure prostate cancer,which killed 27,000 men in the US last year. However, the therapy extended thelives of 512 people with aggressive prostate tumors by four months,compared with patients who did not receive it. Although modest, the latest result shows that harnessing the immune system is a viable way to fight cancer. Oncologist Philip Kantoffat the Dana-Farber Cancer Institute in Boston, said he expectssimilar approaches to other cancers, such as melanoma, kidney cancerand lymphoma, to be approved in five to 10 years and that tweaks toProvenge will see it further extend people's lives.