I have mid upper back pain after i wake. i have had mri and chest xray. if i had cancer would it of caught it?

First, pain due to a: Cancer tends to be more prevalent at night and is constant, not just when you are awake. Tests are good but a clinical evaluation done well is the best way to help diagnose a problem followed by indicated testing. Sounds like it is not cancer based but you should get a diagnosis of what your problem is.

Most likely!: Yes, most likely. With the MRI and a chest xray, if there is any cause for your symptoms, it would most likely identify, any lesion more than 3-5mm in the chest or the spine. I am sure your doc would be able to help you once ha has all the results..

Acid reflux: Can also cause mid/upper back pain. (referred pain).