I want to tell you a story of a man. His name is James A Duke,Ph.D. He worked for over three decades to identify, evaluate, classify and catalog hundreds and hundreds of therapeutic plants. He worked for 5 years for the USDA Medicinal Plant Resources Laboratory specifically to find anti-cancer plants to make into drugs. This is how Tamoxifen was developed. Duke traveled the world to seek out the most medicinal plants in the world. He actually is still alive today. You can read his book, "The Green Pharmacy- Herbal Handbook" where he attempts to bring to the layman an easy to understand guide. He is now retired and lives in Maryland at his home The Green Farmacy Garden. http://thegreenfarmacygarden.com/ is one of his websites about his home.
One of the reasons I'm telling you about him is so that you will understand that plants and herbs have had extensive research. I'm going to direct you to the government website which is very complicated to maneuver If you not a botanist and a web geek. So be prepared! http://www.ars-grin.gov/duke/ While there you will find 5 basic ways to search. Go down to "Activity Search", Then to "Super Activity". Then from there go to the drop down box and find cancer. Then you can choose search. There you will find specific cancers to research. I think all this info will be confusing but also eye opening. I also think it will be a useful tool if you can get familiar with the website. In any case it's all about being informed.