Abstract
Although hematopoietic stem cell (HSC) transplants are curative for some patients with hematologic malignancies, they have been applied primarily to younger patients. Yet, hematologic malignancies are commoner in the older populations. Therefore, despite advances in HSC transplants, many patients, especially older patients, still die of their disease. Umbilical cord blood (UCB) transplants have been shown to produce comparable results to those obtained from unrelated bone marrow transplants for adults with hematologic malignancies. UCB transplants may be particularly suitable for older patients needing unrelated HSC transplants since the incidence of GVHD is lower despite the less stringent HLA-matching requirement. Furthermore, UCB procurement is fast and can be accomplished in two weeks. However, data on the applicability of UCB transplants in older adult patient is lacking. The outcome of 14 consecutive adult patients (9 males and 5 females), 45 years or older, needing HSC transplants but without matched sibling donors in a single institution was analyzed. The median age was 55.5 years (range 45–78). The median weight was 72 kg (range 60–105). The median CD34 cells infused were 2.3 x 105/kg. Four patients received one-antigen mismatched, five patients two-antigen mismatched and five patients three-antigen mismatched transplants. Conditioning regimens consisted of Bu/Cy with (n=5) or without (n=1) ATG, Flu/Mel (n=7) and BEAM (n=1). GVHD prophylaxis consisted of cyclosporin A and methylprednisone. Five patients received double UCB transplants. The diagnosis: AML (n =8; 2 untreated secondary AML, 2 primary refractory AML, 2 secondary AML in CR1, 1 secondary AML in CR2 and 1 AML in CR3 and has failed a previous autologous transplant), CML (n=3; 2 in BC and 1 in CP1), CLL (n =2; both with advanced refractory disease) and SAA due to Hep C (n=1). Despite the age of these patients, Grade I–II acute GVHD occured in 10 patients and Grade III–IV in only 2 patients. Three patients died, all from septicemia, before engraftment could be documented. Other deaths include severe GVHD (n=2), VOD (n=1), stroke (n=1), septicemia (n=1) and leukemia relapse (n=1). Five patients are alive and disease-free. As of August 1, 2007, the 5-year actuarial DFS and OS are both 31% for the group and 50% for those <65 years (Figure 1). All five patients >65 years died within 100 days of transplants. In conclusion, some older patients needing HSC transplants may benefit from mismatched UCB transplants if they are not candidates for autologous transplants and do not have HLA-matched siblings. Obviously longer follow-up is needed in these patients to better determine the long-term effect of this approach in older patients. However, further optimization of the conditioning regimen is needed for patients older than 65 years to reduce early TRM due to toxicities.
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