Dr. my father is 91yrs old and has been diagnosed with stage 3 lymphoma. The doctors suggested a biopsy to my sisters but decided straight on to the chemotherapy. The doctors said that with out the chemotherapy he would die within a two week period.
Thanks for your question on Chat Doctor. Lymphoma is very aggressive malignancy and life-threatening too. And risk is high when patient is old age and having advanced stage malignancy.  Your father is having both risk factors, age 91 and stage 3 disease. So he is at high risk for mortality. And lymphomas are highly sensitive to chemotherapy. With single dose lymphoma start regression. So we should start chemotherapy as soon as possible once patient is diagnosed with lymphoma. So no need to wait, start chemotherapy.  Without chemotherapy survival rate is very low, less than 1 month.