I'm a 66 year old African American male. I had prostate Cancer, of which the cancer was removed robotically in 2010. Recently, I've had discomfort in the middle of my back, and some chest discomfort. Some days I have loss of breath going up and down the steps of my home. I must admit, I've been smoking since my teen years, maybe a pack every two weeks. The back discomfort starts when I'm sitting while breathing in and out. Is there something serious going on here; I'm recently retired, and concerned.