At my request my onco gave me the CYP2D6 test, which determines how well I would metabolize Tam. Should I need to take it she will dose accordingly. Meanwhile I get a Guardant Reveal test every three months to detect cancer cell presence. So far so good. FWIW: I strongly encourage second opinions + doing your own research. I brought the CYP2D6 test to my onco’s attention, then she researched it. Cancer is a business and medicine in this country is driven by big pharma. I realized that to achieve my desired outcomes I must be my own project manager, researching options, managing risks, and coordinating efforts among siloed medical fields (e.g. GI, onco, nutrition). Blessings and hearty encouragement to you all because YOU are your own best advocate.