I Have A Friend With Stage 4 Lung Cancer Spreading

I have a friend with stage 4 lung cancer spreading to stomach and lymph nodes, recently discovered. He has had 1 chemo treatment and last Fri had a heart attack , family was called in Sun. But he rallied Mon and ate a meal. His heart function is 20%. This was his 3 heart attack over yrs.
What should we prepare for considering his condition, should we prepare for this to be his final days?