It may slow down the progression of prostate cancer, but further studies are needed. Basically the studies have revolved around people drinking an 8 oz glass of juice a day to see if it has any affect on this type of cancer. Subjects drink it until disease progression . . which did occur. All subjects eventually had their disease progress even while drinking pomegranate juice. So the juice is being studied further.
Early studies are also being conducted for lung cancer (using mice models) with the hopes of slowing down the progression of the disease.
Problem with all of this is always . . how much juice to use, how often, and how can you tell if it is the juice that is slowing down the progression of disease?
You can check the progress of research online at Pubmed (National Library of Medicine):
http://www.ncbi.nlm.nih.gov/sites/entrez…