Thank you for the gracious welcome, @colleenyoung . I see it's been a bit over a week, and I gather that your colleagues are occupied on other matters. If they find time, I'll be grateful, but don't presume.

It seems to me, as a keenly sciene-interested layman, that American Red Cross's exclusion guidelines (like the FDA guidance they reflect) have unavoidable vague bits, which interact badly with prostate cancer's unusual traits, e.g., where it can be ambiguously inferred (or inferred absent) from PSA metrics, and where it's one of the many (solid-tissue) cancers never known to be transmitted in blood products over the entire history of blood transfusions.

Stop to consider: Blood transfusion has been an everyday thing since blood typing was discovered in 1900 (ABO) and 1902 (AB), 51% of recipients have been female, and a statistically significant minority of those have been immunosuppressed / immunocompromised / immunosenscent. If even one such recipient, over those 120+ years of regular blood transfusions, had ever developed prostate cancer from latent cancer cells in a blood product, we'd already know from the eye-opening coverage in Lancet or NEJM, but it didn't happen.

So, logic suggests one ought to be able to say "Even being ultra-cautious, one can confidently say it's perfectly safe to receive blood from a former prostate cancer patient who experienced biochemical recurrence but is now on androgen ablation, and has maintained unmeasurable PSA for a year-plus and no detection of tumors." But I'll be surprised if I ever hear that, because running a blood bank involves legal self-protection, and thus exclusion policies dictated far more by legal posture than by science.

For what it's worth, it turns out that some non-American Red Cross blood banks are happy to accept and use such donors' blood. Thought you should know.