You are indeed correct that some patients have tumors with BRCA mutations while the non-tumor cells (such as white blood cells) can have a normal BRCA gene. Currently there is not a tumor test for “BRCAness” that is used clinically to make decisions for treatment. There are tumor tests that are being used from a research standpoint to better understand tumors that have a BRCA mutation or behave like they have a BRCA mutation. Examples include the Myriad HRD test and FoundationOne Next Generation Sequencing. However, performing genetic profiling of the tumor will not help guide current therapies. For instance, Olaparib is an FDA approved drug for patients with BRCA mutations but it is not approved for use in the situation you describe. As such, testing the tumor would not guarantee insurance coverage for treatment and it would be considered off-label. However, it might be reasonable to test the tumor for mutations if you were interested in participating in a PARP inhibitor trial that does not mandate germ-line (or inherited) BRCA mutations. The Mayo Clinic Center for Individualized Medicine has expertise in this area and a consultation could be scheduled. The pros and cons of tumor gene profiling should be discussed with your local oncologist.