I Had Colon Cancer Back In 2010. Lately I Have

I had colon cancer back in 2010. Lately I have been having excess mucus (causing a cough), sternal pain and even had sharp pains between my shoulder blades last week. I saw my ENT and received a 14 day dose of levaquin, which has not helped. Last week, I had the sharp pains between my shoulder blades and when to the ED. My troponins were negative x 2 and my chest xray did not show pneumonia. I am concerned that my cancer could have spread. I called today to see about getting a CT. Could these symptoms be anything benign?