As JesichasHope noted, graviola is a great herb but you need more than any single herb or other item to be assured of beating cancer. In addition, graviola works somewhat like chemo in that it lowers cellular activity and thus it may not be all that compatible with many other anti-cancer/immune-boosting items which boost cellular activity. Or so said my good friend and mentor, the late great alternative cancer pioneer Naturopathic PhD Dr. Marc Swanepoel (who developed the SutherlandiaOPC line of Oleander based supplements).
In my strong opinion, beating cancer and making sure it never teturns (which is MY definition of a cure) involves a lot more than simply throwing one or two supplemental items at it. Fighting cancer should be a life-changing experience that requires a combinastion of changes in diet and lifestyle, optimum nutrition, stress/emotional conflict management, daily sunshine/Vitamin D3, physical activity, and - vitally importan - removing and avoiding toxins as well as key cancer-fighting and immune boosting supplements/herbs.