Indications are encouraging, though. You can't harm yourself by drinking green tea unless you take it scalding hot - bad for this kind of tea as well as for your mouth and throat. If you're taking radiation therapy or chemotherapy, it is important to chask your oncologist about any antioxidants you are taking. Green tea would count as an antioxidant. Some beneficial substances can be counterproductive while you're on cancer therapy.
Nothing suggests that green tea cures prostate cancer.
Carlin's study used a strong concentration of active ingredients - about a hundred times what the Lipton company estimates is in one cup of tea. HUman studies are needed to see if indeed green tea extracts really can prevent cancer or slow the growth of existing tumors. Moderate consumption of green tea appears safe. Preliminary evidence exists of the potential effectiveness of green tea as a treatment of cancer. Further research into the effects of green tea and some of its constituents would be worthwhile.