Welcome, @rida. I moved your question to the Breast Cancer group here: https://connect.mayoclinic.org/group/breast-cancer/

CA 19-9 is a test more commonly used for some types of cancer of the pancreas than for breast cancer. Keep in mind that a higher than normal level of CA19-9 can be found in healthy people and can also be found in people with non-cancerous and cancerous conditions. You can read more here: https://cancer.ca/en/treatments/tests-and-procedures/carbohydrate-antigen-19-9-ca-19-9

@cathyras can share her experiences with CA 19-9 testing for breast cancer.

Rida, It sounds like your cancer team is being very thorough. And that is a good thing. I know it is easier said than done, but try not to worry before you know more. You need your focus and energy for today and not wrap yourself up in tomorrow's worries. Will you have a PET scan in 2 days or receive the results of the PET scan in 2 days?