Relapse and late mortality in 5-year survivors of myeloablative allogeneic hematopoietic cell transplantation for chronic myeloid leukemia in first chronic phase

Abstract

PURPOSE Allogeneic hematopoietic cell transplantation (HCT) is curative therapy for chronic myeloid leukemia (CML), but its long-term outcomes are not well described. We studied the long-term outcomes of CML patients in first chronic phase who receive an allogeneic HCT. PATIENTS AND METHODS Our study included 2,444 patients who received myeloablative HCT for CML in first chronic phase between 1978 and 1998 and survived in continuous complete remission for at least 5 years (median follow-up, 11 years; range, 5 to 25 years). Donor sources were human leukocyte antigen-matched siblings in 1,692 patients, unrelated donors in 639 patients, and other related donors in 113 patients. RESULTS Overall survival rates at 15 years were 88% (95% CI, 86% to 90%) for sibling HCT and 87% (95% CI, 83% to 90%) for unrelated donor HCT. Corresponding cumulative incidences of relapse were 8% (95% CI, 7% to 10%) and 2% (95% CI, 1% to 4%), respectively. The latest relapse was reported 18 years post-HCT. In multivariable analyses, history of chronic graft-versus-host disease increased risks of late overall mortality and nonrelapse mortality but reduced risks of relapse. In comparison with age-, race-, and sex-adjusted normal populations, the mortality of HCT recipients was significantly higher until 14 years post-HCT; thereafter, mortality rates were similar to those of the general population (relative mortality ratio at 15 years, 2.3; 95% CI, 0 to 4.9). CONCLUSION Recipients of allogeneic HCT for CML in first chronic phase who remain in remission for at least 5 years have favorable subsequent long-term survival, and their mortality rates eventually approach those of the general population.

Fig 1.

Probability of overall survival by (A) donor source and (B) chronic graft-versus-host disease (GvHD) status. Categories within “other chronic GvHD” include “de novo chronic GvHD, onset ≤ 1 year after transplantation,” “de novo chronic GvHD, onset > 1 year after transplantation,” and “prior acute GvHD, chronic GvHD onset ≤ 1 year after transplantation.” HLA, human leukocyte antigen; URD, unrelated donor.

Fig 2.

Cumulative incidence of nonrelapse mortality by (A) donor source and (B) chronic graft-versus-host disease (GvHD) status. Categories within “other chronic GvHD” include “de novo chronic GvHD, onset ≤ 1 year after transplantation,” “de novo chronic GvHD, onset > 1 year after transplantation,” and “prior acute GvHD, chronic GvHD onset ≤ 1 year after transplantation.” HLA, human leukocyte antigen; URD, unrelated donor.

Fig 3.

Relative excess mortality (dark blue line) compared with age-, sex-, and race- matched general population for patients surviving in remission for at least 5 years after myeloablative allogeneic hematopoietic cell transplant for chronic myeloid leukemia. A relative risk of 1 indicates that the mortality rate of the population of interest is similar to that of the general population. Light blue lines represent 95% CIs.