What Causes Painful Lump On Sternum With Family History Of Lung Cancer?

Hi, I have this pain, on and OMG, right across my bra line, it comes and goes, seems only if I have bra on numerous days, however, I have had trama years ago to my chest bone, but it s a stinging sharp pain, and there s a lump, on the left side of my sternum, I do have inhalers, and breathing issues at times. I am 50. My Dad passed two years ago from lung cancer, should I be concerned? It seems the only time it is irritated is I wear my my bra for prolonged time,