What to do if my dad has late 4th stage emphizima and late 3rd early 4th stage adenocarcinoma (small cell lung cancer)?

See Oncologist: Small cell lung cancer is generally divided into "limited-stage" in which the cancer is confined to one part of the chest treatable by radiation and "extensive-stage" disease in which it has spread to both lungs or other places in the body. Limited stage disease is usually treated with radiation and chemotherapy. Extensive stage with chemotherapy alone at first and possibly some brain radiation.