Jake: "...it would seem very likely to scientific bonehead me that a verified decrease in CTCs would reliably predict shrinking or disappearing tumors."

That makes two of us. I may be wrong, but I instinctively start my thinking here with the notion that if a patient does not have any CTCs - then I have to believe that the patient, definitively, could not earn a cancer diagnosis. (detectable or otherwise). The inverse being a state where the patient has some measure of CTCs, then the patient has cancer or a medical risk of an active but undetected cancer.

Thanks again.