Could you tell me what is the life expectancy for a 66 year old male just diagnosed will cancer in bowel, lungs and brain?

Unknown: No one can tell you dates, only percent survival. So lower with large tumor burden. So if tumor spread to lung brain etc this is stage 4. Also depends on how functional one is. I would talk to the oncologist about palliative and hospice care otion if no one has before. Ask questions to the doctor and write them down so you will not forget.