Nephrologist and Oncologist
I have gone through your query and understand your concern.
As your parathyroid hormone, mammogram as well as chest x-ray is normal, then it may be due to cancer as you suspected.
Please do routine blood tests including kidney function tests, Complete blood count
(CBC) and urine tests, Bone scans, serum alkaline phosphatase
Then better consult a Nephrologist
Hope this helps.
Please write back for further queries.