- Joined
- Apr 3, 2019
- Messages
- 4,752
- Reaction score
- 11,006
Not just "Probably [left behind disease was detected], yes"; left behind macroscopic disease was definitely detected in Z0011. And in Veronesi's trial as well. Doctors (pathologists) saw the macroscopic disease based on tissue handed them by other doctors (surgeons).
Now comes the part where we have to use logical induction and maybe a little imagination. Imagine you are in the OR with ENT and doing a neck dissection on a cN0 neck. The ENT hands you a 0.8cm neck node. You slice it in two, stain it, and discover that essentially 0.7cm of the node is replaced by cancer. He hands off 15 other nodes... all of them are cancer free. At this point in the story if the patient comes to see you one month later, we suspect or say there's microscopic disease in the neck. Now what if we had a device that could reverse time in the OR and after the ENT handed you the 0.8cm node we could re-implant that node back in the neck? Would we still call the known grossly positive node microscopic disease, or macroscopic? Would you Rx the node 50 Gy, or more?
Not "everything is macroscopic." I am referring to the Fletcherian concepts of subclinical/microscopic. He suggested a 3mm or smaller focus of cancer, containing a million or less cancer cells, was microscopic; obviously per breast cancer staging rules "microscopic" means a 2mm or smaller focus. Fletcher: "One can state that subclinical [which includes microscopic] disease is present only if there are no palpable masses in accessible lymphatic areas, or if the surgical specimen gives evidence that all gross cancer has been removed." In the case of Z0011, we can state by a proof through induction principle that a large proportion of women who are SLN-sampled-only have surgically (and radiotherapeutically) untreated macroscopic disease; only a teeny proportion of this proportion however will ever have a clinical problem from this macroscopic disease. Same issue in the Veronesi trial but even more striking because none of the patients got chemo or radiation: "In fact, the follow-up of patients treated by Halsted mastectomy showed that only 15 of them had a parasternal recurrence, traced to the development of an internal mammary metastasis, during the first ten years from surgery. If it can be assumed (by analogy with the other group treated by extended mastectomy) that microscopic* incidence of i.m.n. metastases was on the order of 20%, then it would be expected that 75 patients in the Halsted group would have clinical parasternal recurrences. Therefore, the observed vs. expected ratio is highly statistically significant ( P<0.0001)."
To "boost" PET+ IMNs, we would have to make some leaps in logic not as straightforward. We'd have to assume that PETs are reliable for LR staging (when many guidelines and data suggest they aren't great), we'd have to assume SUVs correlate with cancer cell number, and we'd have to assume that high-dose irradiating IMNs on the basis of PET findings will have a more beneficial positive effect than lower-dose irradiating IMNs on the basis of conventional staging methods.
That's a lot of assuming.
*Veronesi wasn't savvy to the Fletcherian microscopic concept 😉
