Hi! @peggydobbs :

Yes, what the other medical oncologist told you is true, that it's unclear how to change treatment plans based on the results of the Signatera test. This is because a Negative result suggests a lower likelihood of recurrence and the current ongoing treatments plan is on the right track, but a Positive result indicates the presence of ctDNA, oftenly identifying recurrence before it is visible on imaging. I think if the Signatera test shows a "positive result" with an elevating value of a patient's blood work over time, a competent medical oncologist should start thinking about something different to provide his/her patient with more effective treatments. This tool only indicates that it is time to re-evaluate the current treatment plan, but it won't tell folks how. Perhaps this is one of the reasons that not many medical oncologists favor this tool...

As for the question of whether Medicare covers the tumor markers blood tests, I truly don't know; for my PCP works at the hospital of a research university, she orders the quarterly blood work for me, I then go to the hospital for the blood test accordingly. Luckily for us, the values of my tumor markers have been staying relatively low ever since I started taking Anastrozole (one of the aromatase inhibitor medications treating patients with high ER+, PR+ BC), thus reassuring us the effectiveness of my current treatment. My PCP and I have an agreement though: should those values of tumor markers start trending higher than the normal range someday, we then need to bring it to the attention of my medical oncologist to re-evaluate my treatment plan. I guess we'll cross that bridge when we come to it... I am very grateful for my PCP's research oriented mind.

Sorry for such a lengthy note, my friend:(. Wishing you all a better journey ahead with hope, peace, and love!