Higher-Risk MDS, Two Patients: When to Transplant and Whether To At All
Two men, the same higher-risk MDS diagnosis three weeks apart, the same complex karyotype. One argument is about the fortnight before a transplant everyone agrees on; the other is about whether a comorbidity index computed from a chart should be allowed to decide anything.
D.L., a 58-year-old high school football coach, was found to have higher-risk myelodysplastic syndrome after a preseason physical turned up cytopenias nobody could account for. His IPSS-R sits in the higher-risk band on the strength of a complex karyotype more than anything else — his marrow blast percentage is 7%, elevated but not by itself what is driving the score — and higher-risk MDS left alone runs in single-digit months to a couple of years rather than the years-to-decades course lower-risk disease can follow. His younger brother is a confirmed HLA match. His HCT-comorbidity index is 0 to 1: no diabetes, no pulmonary or renal impairment, a man who was running sideline drills the week before he was diagnosed.
None of that is contested, and the transplant decision was effectively made the day the donor typing came back. What the team is arguing over is the fortnight before it. Going straight to conditioning forecloses the risk that a complex karyotype does what complex karyotypes do — evolve, or tip outright into acute leukemia — while everyone waits. A short azacitidine course beforehand is the competing move, on the argument that arriving at transplant with a lower marrow blast burden is associated with better outcomes on the far side. At 7% blasts, though, he has less burden available to reduce than the patients that argument was assembled from, which shrinks the expected gain without erasing it: not a reason to delay indefinitely, but a reason to ask whether immediate is actually better than imminent.
With a matched sibling donor confirmed and an HCT-comorbidity index of 0 to 1, I'd move to conditioning promptly and with minimal delay. The variable I'm weighting is his karyotype rather than his blast count: complex-karyotype MDS is the subgroup in which the interval before transplant is least safe to spend, because clonal evolution is what that cytogenetic profile does, and every week of hypomethylating therapy is a week of selection pressure applied to a clone that has already demonstrated genomic instability.
If his cytogenetics were intermediate I'd be far more relaxed about two cycles of azacitidine — the argument I'm making is specific to the karyotype, not a general preference for speed.
I agree transplant shouldn't wait long, but 'promptly' doesn't have to mean 'without any bridge.' A short azacitidine course to bring his marrow blast percentage down before conditioning is associated with better post-transplant outcomes in the literature — this isn't the same as the delay-for-comorbidity-management question that comes up in less fit patients.
Going straight to transplant isn't obviously safer just because he can tolerate the procedure well — tolerating conditioning and controlling disease burden going into it are two different questions.
Agreed: two cycles of azacitidine as a bridge, then proceed to myeloablative allogeneic transplant, rather than either extreme of no bridge at all or open-ended HMA therapy before transplant is revisited.
M.C., a 72-year-old retired accountant, got the same higher-risk diagnosis three weeks after D.L. from the same community oncologist, with the same complex karyotype and a marrow blast percentage of 9% — by disease alone, the more advanced of the two. By everything else he is the harder patient. Type 2 diabetes has been poorly enough controlled to produce an A1c of 9.1%; his creatinine clearance is 42, stage 3 chronic kidney disease; and an infarct six years ago left him with an ejection fraction of 45%. Those three items are what carry his HCT-comorbidity index to 3 or above, the band associated with substantially elevated transplant-related mortality even under reduced-intensity conditioning — and the index reaches that conclusion from his chart, not from any test ordered for the purpose.
His disease is, if anything, further along than D.L.'s, which is what makes the question uncomfortable rather than academic. Azacitidine without transplant offers real disease control that is also reliably temporary — hypomethylating therapy alone rarely produces durable remission in higher-risk MDS — so the choice is less between cure and control than between a procedural risk accepted now and a relapse expected later. Reduced-intensity conditioning remains the only realistic route to long-term control he has. Whether his heart at an ejection fraction of 45% and his kidneys at a clearance of 42 could actually survive it is a question a comorbidity index computed from chart review is designed to raise and structurally unable to answer, and the cardiology and nephrology evaluations that could answer it have not been ordered.
An HCT-comorbidity index this high is associated with substantially elevated transplant-related mortality even under reduced-intensity conditioning. Continuing azacitidine without transplant isn't giving up on disease control — it's declining to trade disease risk for a procedural risk his cardiac and renal status may not survive.
I'd want that formally tested before we close the door. HMA therapy alone rarely produces durable remission in higher-risk MDS, and transplant remains his only realistic path to long-term control. A chart-review comorbidity index is a screening tool, not a final verdict — a real pre-transplant cardiology and nephrology workup could show his ejection fraction and renal function tolerate reduced-intensity conditioning better than the index alone suggests, or confirm they don't.
Declining transplant on an index score without that workup risks foreclosing his only curative option on a screening estimate rather than an actual answer.
Agreed: continue azacitidine now and complete formal cardiology and nephrology pre-transplant evaluation before any final transplant decision.
Not agreed: the geriatrician's position that his comorbidity index alone should be sufficient grounds to decline transplant was not adopted, but was not dismissed either — if the formal workup confirms significantly impaired cardiac or renal reserve, that position becomes the operative one rather than a cautious opening statement.