My mother was diagnosed with stage 4 lung cancer in December. It has taken over quickly and she now has difficutly in eating, getting up, and can't walk far without becoming out of breath. Recently she started vomiting a greenish yellow mucus. Is this a sign of the progression or is this typical of stage 4 patients. She has had one radiation treatment and it scheduled to start chemo on tuesday. I don't think she will be strong enough to begin it though. Is this the start of the end or will this pass with some treatment? Saying that we were blindsided by this would be putting it mildly. Any help is greatly appreciated.