Yes. There are a couple of compounds in green tea that have been shown
to exert anti-cancer effects. The antioxidant in green tea has been
shown to bind to tumor cells from a variety of cancers including lung,
breast and prostate. Other chemicals have been shown to block the aryl
hydrocarbon pathway (which can activate genes involved in cancer).

Green tea is also thought to lower cholesterol and reduce the risk of
rhematoid arthritis.

Here's some leads to answer your question:
http://my.webmd.com/content/article/83/97903.htm
http://news.bbc.co.uk/2/hi/health/3125469.stm