I am a breast cancer survivor, completed treatment august 2019. had radiation and lumpectomy on left breast. often experience pain on this side but now there is a sharp intermittent pain behind the rib cage. does not feel muscular. no other symptoms.

Need to examine: It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. It would be prudent to see your doctor who has been treating you. You may take Paracetamol for pain, no more than 4 g in one day, no alcohol. Wish you good health!

Check up with oncolo: Nearly all patients with breast cancer require regular follow up with their treating physician. The follow up is typically every 4-6 month intervals. The purpose is to monitor your body for any recurrence of Cancer which can occur in a varying %age of patients. If you have pain which is getting worse, you should have an X-ray or scan done to check your bones which is a common site of recurrence.