Is Xeloda “necessary” after chemo, surgery and radiation?

NV2020

II have questions about Xeloda.

My primary, local oncologist and second opinion oncologist from Dana Farber have both recommended Xeloda based on "currently accepted data and research".

I was diagnosed with TNBC last August at the age of 61. I have just completed the "big three" : AC and Taxol chemo, full right mastectomy and 6.5 weeks of radiation. (I did not receive a complete pathological response to the chemo, so after surgery I went on to radiation. The post-surgical pathology report revealed a micromestasis with one positive lymph node). I am now scheduled to start Xeloda next week and I am having second thoughts about it.

The Dana Farber oncologist confirmed that there is current controversy about whether Xeloda is even effective with patients who have the "basal sub-type" of TNBC. My local oncologist says I have basal-type TNBC, though I have not had the genetic EGFR and CK5/6 testing that identifies this. When I requested these tests, she declined to order them as they are "not FDA approved" and thus the health insurance company wouldn't pay for them. (Regardless, I am willing to pay for these tests on my own.). She also opines that it's essentially a moot issue as adjuvant Xeloda should be used, regardless of subtype.

My local oncologist additionally says that I have completed the "required" three therapies as noted above and thus Xeloda is an optional "extra". This statement, as well as the lay person research I have conducted, leads me to believe that while "standard of care", Xeloda is not yet clinically considered an "automatic" treatment like AC and Taxol for TNBC. I also wonder if there may be regional differences in use and practice (e.g., these states or this region generally promote the use of adjuvant Xeloda. I live and treat in Reno, Nevada).

I am not opposed to further chemo. (In fact, I am looking at a Mayo Clinic clinical trial for a TNBC vaccine which includes the use of Cytoxan for both arms of the study. Only one group would receive the vaccine though.)

In short, I'm wondering if Xeloda is even worth enduring the 6 months of side effects if its efficacy is "iffy" for certain sub-types of TNBC. And if the goal of adjuvant therapy is a pile on" treatments, would it be better to enter the clinical trial with known Cytoxan and the possibility of a vaccine on top of that

Any information or guidance you could provide would be greatly appreciated.