Allogeneic Hematopoietic Stem Cell Transplantation is Underutilized in Older Patients with Myelodysplastic Syndromes

Allogeneic hematopoietic stem cell transplantation (HCT) is the only curative treatment for myelodysplastic syndrome (MDS). The proportion of MDS patients referred for transplant evaluation, those undergoing transplantation and the reasons for not undergoing transplant are unknown. In this retrospective analysis, pre-defined HCT eligibility and indications criteria were applied to 362 unselected patients with newly diagnosed MDS seen by Leukemia faculty between 2008 and 2015 at Memorial Sloan Kettering Cancer Center. Two hundred ninety four patients (81%) were deemed eligible for transplant and among these, transplant was considered indicated in 244 (83%). Of these, 158/244 (65%) were referred for transplant evaluation at a median of 3.9 months from diagnosis. Overall 120/362 (33%) underwent transplant at a median of 7.7 months from diagnosis. Metastatic solid organ malignancy was the major reason for transplant ineligibility (54%), and death due to MDS, which occurred in 41% of candidates who were not transplanted, was the major reason for not undergoing transplant. Factors associated with a lower likelihood of referral for transplant evaluation included age ≥65 (p<0.001), ≥2 co-morbidities (p=0.008), intermediate-1/low risk MDS (p<0.001), <5% blasts at diagnosis (overall p<0.001), having medicare/medicaid health insurance (p<0.001), not being married (p=0.017) and diagnosis between 2008-2011 (p=0.035). On multivariate analysis adjusting for all of the previous, diagnosis between 2008-2011 (p<0.001), age ≥65 (p=0.001) and <5% blasts at diagnosis (overall p=0.031) were associated with a lower likelihood of referral for transplant evaluation. Factors associated with a lower likelihood of undergoing transplant included age ≥65 (p<0.001), ≥2 co-morbidities (p=0.003), intermediate-1/low risk MDS (p<0.001), <5% blasts (overall p<0.001), very low/low/intermediate risk IPSS-R karyotype (p=0.018) and having medicare/medicaid health insurance (p<0.001). In multivariate analysis adjusting for all of the previous, age ≥65 (p=0.021), presence of ≥2 comorbidities (p=0.018) and <5% blasts (overall p=0.011) were associated with a lower likelihood of undergoing transplant. The results highlight that transplantation for MDS remains underutilized particularly for candidates over the age of 65.