Could Pain In Chest Radiating To The Back Be Due To Lung Disease?

I am 65 yrs old and have 2 different chest pains. Have had all the tests for my heart and they say it is not my heart. Had GI endoscope and had h pylori infection but cleared that up with triple dose of antibiotics. Still have chest pain.....one pain is center of chest and comes on whenever. I can t associate it with any particular activity. the other pain is in left chest..gnawing pain sometimes felt thru to my back. Also pain thru to back with center of chest pain. Where do I go next? So frustrating. Could it be my lungs?