It would have been better had your father-in-law been able to receive chemotherapy
for his disease. However, i presume that in view of his advanced age, the decision not to take chemotherapy must have been taken, and he was placed on supportive treatment. Going by the rate of transfusions that your father-in-law has been requiring regularly and the complications that he already has started to develop, he is unlikely to survive for more than a few weeks (2-3) in the absence of active treatment in a hospital and even that is being hopeful. You have to take a collective informed and reasonable decision regarding the continuation of therapy in this regard.