Does this sound like it could be Lung Cancer (Pancoast Tumor?)

About a year ago I started getting sharp pains in my shoulder. Well a little lower actually breast/pectoral area. It literally takes my breath away. It feels like I am being stabbed! I also am having trouble with my left arm... mainly extreme pain & the loss of feeling & muscle in my hand/wrist. My Drs at first thought it was the Ulnar Nerve as I have Peripheral Neuropathy but the pain is getting worse & worse. I also have a tingling sesation below my neck sort of on the spine & a few months ago I noticed when I touched my right ribcage it was numb. I have been smoking since I was 15yrs old (now 37) & am a high risk because of my illnesses. (Pernicious Anemia, Peripheral Neuropathy, Barretts Esophagus) I have also been losing weight (probably 20-25lbs) & have been getting annoying night sweats.