Risking life with treatment which might prolong life

Igros Moshe (Choshen Mishpat II #74.5) Question Is it permitted or obligated to risk dying in order to possibly live longer(Avoda Zara (27b)?  Answer I have previously written (Igros Moshe YD III #36) that this is merely permitted in a situation which is 50-50. However if the doctor has determined that this treatment is beneficial than it becomes obligatory. Nontheless if this an operation on internal organs in a delicate location and thus there are major differences between doctors in the success rate it is important to utilize only the best doctors. In an emergency situation one can rely on any highly competent doctor or lacking even that on any doctor as long as it is reasonably certain he won’t make it worse. . If the patient decides on his own that he wants the procedure  because he feels it will be beneficial even though  he says he knows it might make things worse than if he can not be discouraged it should be permitted to prevent him from deteriorating. But if it is clear that it would be harmful it is prohibited. This matter requires careful deliberation of the doctors and patient. However if the patient  doesn’t want to place himself in danger even if it might be beneficial  he is clearly not obligated unless most people benefit and live from the treatment than he is obligated. If the majority are not cured by this treatment but they don’t get worse it is possible he is still obligated. However it is difficult to rely on the doctors in this circumstance  and thus the wishes of the patient and family if they want ir it is permissible and if not he is not obligated.  If they can not afford the procedure than it is appropriate to ask for donations. If the patient is a child or an adult who can nhot decide, the parents or family can decide for him. If there is no family then the city beis din decides. In a situation where the patient refuses treatment it is might sometimes be permissible to force him to take the treatment even if it requires tying him up.  In conclusion if the doctors decide that the treatment is needed and beneficial then it is obligatory for the patient.  

Igros Moshe (YD III #36) Question Is it permitted or obligated to risk dying in order to possibly live longer(Avoda Zara (27b) A patient has holes in his heart which the doctors say is life threatening. And he will die in a short time. They want to plug the holes with plastic and the doctors say if the operation is successful he will live another  15 years or it might kill him?Answer  There is no distinction made of a life expectancy of a day or two vs months. In fact an expectancy of up to a year is treated the same for permision. The reason is that expectancy of more than 12 months is viewed as a long time and one can not rely on the evaluation of doctors that the treatment will at best work more than a year. If the doctors say even with treatment he won’t live a year and might die faster because of the treatment it is not permitted

Igros Moshe (YD III #36) Question: Is the patient obligated to risk death with treatment because of the possibility of a normal life expectancy? Answer He is allowed but not obligated. Even though this is not stated in Shulchan Aruch, if most cases result in added life it is reasonable that it is obligatory.If the odds are only 50/50 it is reasonable that it is not obligatory.