Patient Story: As more states make the use of medical marijuana legal, doctors and lay people alike question its use, its efficacy and the amount of research being done to help prove it is safe to treat certain conditions. Meet Beverly McClain who uses medical marijuana to help with her symptoms caused by the treatment she is receiving for Stage IV breast cancer. Myth or Medicine: Do the therapeutic benefits of smoking marijuana outweigh the health risks to your lungs? Second Opinion 5: Five things you may not know about medical marijuana.