In advanced stages, when the disease has spread, there is no definitive cure. It is also true that some treatments can slow the disease and prolong life. But people have a desire to live, and they want to try. There are cases in which family members and the patients themselves have given up on the treatment at the beginning, but they are in the minority.
Large-scale equipment costs a lot. So is the cost per use. In addition, the side effects of chemotherapy and radiotherapy are very high, and the supporting drugs are also very expensive. Each diagnosis, treatment, not only the cost of the equipment, but also the doctors, nurses and medical staff who provide medical services. The cost of this is also reflected in the cost of treatment.
For example, if a nuclear magnetic device costs 10 million dollars and is designed to last for 10,000 cycles, it will cost at least 1,000 rounds per cycle, and that doesn't even include the cost of maintaining the device, the staff, and the premises. This is just an analogy, in reality the price will be higher, because the design life is not that long.