With stage 4 lung cancer, what is the life expectancy?

Greatly depends. That depends on many factors: the type of cancer, how much it has spread, whether it is responsive to treatment, whether you have received treatment, etc. Etc. It is very difficult to make a prognostication about "life expectancy." stage 4 cancer, of whatever type, can be very difficult. It is important you get all the information you need that is accurate and helpful.
Greatly depends. That depends on many things: type of cancer, the degree of spread, to where it has spread, how much treatment you have received, etc. If you have stage 4 lung cancer, you need to discuss all the aspects of treatment, prognosis, and diagnosis with your doctor, especially the oncologist, or cancer specialist.
Low, less than 5%. In stage IV lung cancer, the 5 year survival is <5%. This is where the lung cancer has metastasized to anywhere else in the body. Palliative care might be the best option at this point.

Related Questions

Stage 4 lung cancer no chemo tumor grew & cancer spread, clinical trial only now, on oxygen for sob, blood clots in legs, what is life expectancy?

Hard to say/depends. At this stage of lung cancer, the options are limited as is survival. If treatment is done , it's usually chemotherapy and radiation and/or surgery after adjuvant chemotherapy. There are certainly trials out there and i would recommend talking to your doctor before starting any, but the chance for success is likely limited, as the 5 year survival of stage IV is <5%, but it doesn't hurt to try. Read more...
Does not sound good. With all you are explaining, life expectancy may not be as long as we hope. Typically patients with progressive disease and clots have a shorter survival. My thoughts and prayers extended to you. Read more...

What is the average life expectancy for patients diagnosed with non small cell lung cancer stage 4?

Very low-5% 5 yr. . Stage IV non-small cell lung cancer is metastasis to any site other than lung, like brain. This has a very low 5 year survival of 5% or less. Very few (about 20%) have localized dissease at diagnosis. Read more...
Not great . Less than 10% of patients survive past 5 years. Average life expectancy is about a year on average. Read more...