I've had discomfort in the left shoulder blade area for a month and google says that it is lung cancer.. do you have any ideas?

Be seen: It could be a great many things. See your physician for an examination, and xray.

And now for the real: answer. RARE under age 30 http://www.cancerresearchuk.org/cancer-info/cancerstats/types/lung/incidence/uk-lung-cancer-incidence-statistics#By2 FROZEN SHOULDER should be a reason to see A PRIMARY D.O. dr. http://www.mayoclinic.org/diseases-conditions/frozen-shoulder/basics/definition/con-20022510