SEATTLE — Sept. 7, 2004 — Many patients who undergo bone marrow or stem-cell transplantation experience a decline in mental skill and physical coordination after treatment. A new study by researchers at Fred Hutchinson Cancer Research Center shows that these effects are largely temporary and that most patients can expect a return to normal function within a year of their transplant.
Any lingering physical or mental impairments likely are not the result of the transplant process for most patients, according to a study published in the online version of Blood, the Journal of the American Society of Hematology. The study can be found at http://www.bloodjournal.org/cgi/content/abstract/2004-03-1155v1.
"In all areas except coordination, function is back to normal within a year. Most people do recover well from their transplant treatment," said Karen L. Syrjala, Ph.D., head of biobehavorial sciences at Fred Hutchinson and lead author.
Researchers know that the powerful chemotherapy drugs leukemia and lymphoma patients take to prepare for bone marrow or stem cell transplantation — or later to fight graft versus host disease — can impair neurocognitive function. What hasn't been known, until now, is whether impacts such as decreased memory or the ability to write with a pencil are long lasting.
"The results of this study have major implications for advising health care professionals, patients and their families about expectations after transplant," the authors wrote. "Overall, patients and their families can be advised that, while short term neurocognitive effects of HCT are severe, most patients return to their pre-transplant levels of cognitive function by one year after transplant."
Syrjala and colleagues from the University of Washington departments of Psychiatry and Behavioral Sciences and Rehabilitation Medicine conducted what they believe was the first prospective, longitudinal research to determine the long-term effects of transplantation on cognition and coordination. Impetus for the study was patient complaints of cognitive difficulties following myeloablative hematopoietic cell transplant or HCT.
"We were hearing from patients that they thought their brains weren't working the same way they did before their transplant," Syrjala said. "Some patients were reporting difficulties with memory and concentration, for example. Cancer patients often call this 'chemo-brain.' We didn't know if this was part of the normal aging process or a result of their treatment. And we wanted to know if they got better after treatment was finished."
Myeloblation means the patient's own diseased bone marrow is destroyed by drugs and/or radiation in preparation for the transplantation of healthy bone marrow or stem cells from another donor. Hematopoietic cell transplantation is an effective and widely used treatment for blood malignancies.
The researchers gave a series of neuropsychological tests to 142 patients at Fred Hutchinson who were about to undergo an allogeneic (from another donor) hematopoietic cell transplant. The same tests were administered 80 days after transplant and again at one year. The tests examined a range of functions from gross and fine motor strength to cognitive flexibility and verbal fluency, and were adjusted for age, gender and education.
The results showed that performance on all the tests declined from pre-transplant to 80 days post transplant. By one year, the patients had returned to their pre-transplant levels of attention, speed of information processing, learning, visual-motor integration, verbal fluency and verbal memory. In contrast, grip strength and motor dexterity remained below pre-transplant levels at one year. Although verbal skills returned to pre-transplant levels, verbal test scores generally were below population norms.
The researchers concluded that long-term cognitive problems were likely related to disease or treatment effects that occurred before their transplants. On the other hand, coordination and strength difficulties at one year were related to transplant treatments. Many patients remain on medications at one year and so the researchers hypothesized that these patients will continue to improve as they complete their treatments. The researchers are following the patients up to five years after treatment to find out whether they continue to improve.
This work was supported by grants from the National Cancer Institute.
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Fred Hutchinson Cancer Research Center
The Fred Hutchinson Cancer Research Center, home of two Nobel Prize laureates, is an independent, nonprofit research institution dedicated to the development and advancement of biomedical technology to eliminate cancer and other potentially fatal diseases. Fred Hutchinson receives more funding from the National Institutes of Health than any other independent U.S. research center. Recognized internationally for its pioneering work in bone-marrow transplantation, the center's four scientific divisions collaborate to form a unique environment for conducting basic and applied science. Fred Hutchinson, in collaboration with its clinical and research partners, the University of Washington Academic Medical Center and Children's Hospital and Regional Medical Center, is the only National Cancer Institute-designated comprehensive cancer center in the Pacific Northwest and is one of 38 nationwide. For more information, visit the center's Web site at www.fhcrc.org.