Cigarettes are WAY worse than weed, depending on where you get it. If it's medical marijuana, cigarettes are SO much worse. Street weed is worse though. Weed is used on cancer patients to help reduce the spread of cancer within the body while cigarettes CAUSE cancer to the lungs, also known as lung cancer. I'm not quite sure if smoking weed can help with lung cancer, but I'll look more into it. But from what I know and what I have smoked, weed does not cause cancer or any real damage to your body.