My mom was diagnosed with Breast Cancer in 1980. She had a mastectomy and chemo and was cancer-free for 10 years. The only lifestyle change she made was to quit smoking. When the cancer came back, she again pursued conventional treatment (chemo and radiation), and she ultimately lived five more years. Granted, the last few years were pretty rough going.
A friend of mine was diagnosed with uterine cancer early enough that it most likely could have been successfully treated with conventional medicine. But, she was a chiropractor and very much into alternative healing modalities, so she refused conventional medicine and died about a year later.
Steve Jobs was blessed in having a more treatable type of pancreatic cancer, but he blew his chance to survive by doing alternative remedies until it was too late.