I have a question maybe someone could shed some insight on.. my dad has coughed up a little bit of blood mixed in with some mucus yesterday and today. He has been coughing a little on and off since he was diagnosed but hasn't had any blood in it since probably late June. I am planning on calling his doctor on Monday, and he starts radiation in a week. but Anyone with small cell lung cancer experienced this after chemo? How concerned should we be?