An analysis of long-term outcomes for elderly patients with advanced hematologic malignancies suggests they do as well as younger patients when treated with allogeneic hematopoietic cell transplantation following nonmyeloablative conditioning.
In patients aged 60-75 years, the protocol yielded a 5-year overall survival rate of 35% and a progression-free survival rate of 32%, according to a report in the Nov. 2 issue of JAMA. The overall 5-year survival rate was as high as 69% among the patients who had the lowest comorbidity scores and lowest disease risk.
Half of these older patients never required hospitalization either during or after treatment, and two-thirds of the survivors returned to normal or near-normal physical functioning, said Dr. Mohamed L. Sorror of the transplantation biology program at the Fred Hutchinson Cancer Research Center, Seattle, and his associates.
"These results are encouraging given the poor outcomes with nontransplantation treatments, especially for patients with high-risk acute myeloid leukemia, fludarabine-refractory chronic lymphocytic leukemia, or progressive lymphoma," the investigators noted. They assessed outcomes in 372 patients aged 60-75 years who were enrolled in prospective clinical trials of the therapy at 18 medical centers in 1998-2008. The study subjects were being treated for hematologic malignancies including leukemia, myelodysplastic syndromes, myeloproliferative diseases, multiple myeloma, and lymphoma.
Since older patients are not eligible for the intense cytotoxic conditioning regimens that precede high-dose allogeneic hematopoietic cell transplantation, these patients instead underwent nonmyeloablative conditioning that relies on graft-versus-tumor effects to cure the cancer. This included fludarabine and a low dose of total-body irradiation before transplantation and a course of immunosuppression with mycophenolate mofetil and a calcineurin inhibitor (cyclosporine or tacrolimus) afterward.
"These findings should help allay reluctance in entering older patients with hematologic cancers in non- myeloablative [transplant] protocols."
After a median follow-up of 55 months (range, 12-133 months), 133 patients were still alive. Overall 5-year survival was 35%, and 5-year progression-free survival was 32%.
When the data were analyzed by patient age, 5-year overall survival was 38% for those aged 60-64 years, 33% for those aged 65-69, and 25% for those aged 70 and older. "Regardless of age, 5-year survivals ranged from 23% in patients with high comorbidity scores and high disease risk to 69% in patients with low comorbidity scores and low disease risk," Dr. Sorror and his colleagues said (JAMA 2011;306:1874-83).
Approximately two-thirds of the survivors at 5 years had complete resolution of their graft-versus-host disease (GVHD) symptoms and were able to discontinue immunosuppressive medications after a median of 2.5 years. Both the incidence and the resolution of GVHD in these older study subjects were comparable to those reported in the literature for younger patients treated with high-dose hematopoietic cell transplantation.
"These findings, together with the normal to near-normal performance status of surviving patients, should help allay reluctance in entering older patients with hematologic cancers in nonmyeloablative [transplant] protocols," the researchers noted.
Disease progression and relapse accounted for most (135) of the 239 deaths. Relapse rates were 33% at 1 year and 41% at 5 years. Most nonrelapse deaths were attributed to multiple organ failure, GVHD, and infections.
Dr. Sorror and his associates noted that hematologic malignancies are predominantly diseases of the elderly, and the incidence is expected to increase up to 77% during the next 20 years, due in part to the aging of the general population. Yet the latest figures show that only 12% of patients treated with hematopoietic cell transplantation in recent years were older than 60 years.
"This clearly highlights the reluctance of physicians to offer allogeneic hematopoietic cell transplantation to elderly patients," they said.
The investigators are now starting a multicenter longitudinal study to follow such patients from diagnosis onward, in the hope of elucidating "the reasons behind the low rate of referral of older patients to transplantation, [as well as] how nonmyeloablative [transplantation] outcomes compare with those after conventional therapies."
This study was supported by the National Institutes of Health and the Leukemia & Lymphoma Society. Dr. Sorror’s associates reported numerous ties to industry sources.