Countless people with cancer and blood disorders have been saved by receiving healthy blood stem cells through hematopoietic cell transplantation, or HCT. Yet, transplant recipients may develop other chronic health conditions, according to a new City of Hope study that recommends patients undergo continuous monitoring after HCT to avoid future complications.

Photo of Smita Bhatia, left, and Can-Lan Sun (Photo by p.cunningham)

Department of Population Sciences researchers Can-Lan Sun, M.D., Ph.D., associate research professor, and Smita Bhatia, M.D., M.P.H., Ruth Ziegler Chair in Population Sciences, presented their findings at a press briefing during the 53rd annual meeting of the American Society of Hematology. City of Hope researchers shared their work through more than 50 oral and poster presentations during the meeting, which took place Dec. 10 to 13, 2011, in San Diego.

Patients who survive a decade or longer after HCT are at greater risk — compared to their cancer-free siblings — of developing chronic health conditions like cardiovascular, endocrine or musculoskeletal disorders. Their risk of new cancers, psychological problems and long-term generalized pain or discomfort, called somatic distress, also increases.

“Previous research has shown that morbidity increases with length of survival after an HCT, but this is the first study to specifically examine the burden of morbidity in those who have survived 10 or more years after a transplant,” said Sun, who is lead author on the study.

Drawing from the National Cancer Institute-funded Bone Marrow Transplant (BMT) Survivor Study, which is the largest of its kind and is led by Bhatia, the researchers analyzed data from 366 HCT patients who survived a decade or longer and their 309 siblings.

The average age when most patients in the study had their HCT was 22, and the average age when they participated in this study was 37. The total 15-year incidence of chronic health conditions in survivors was 71 percent, and the incidence of severe life-threatening conditions or death was 40 percent.

Among HCT survivors, 74 percent reported at least one chronic health condition, compared with 29 percent of their siblings. And 25 percent of survivors reported severe life-threatening conditions such as heart attack, stroke, blindness, diabetes, musculoskeletal problems and secondary cancers — compared to only 8 percent of their siblings.

Besides studying late medical effects and quality-of-life issues, researchers also explored the psychological impact. Anxiety and depression were comparable between survivors and siblings, yet survivors were nearly three times more likely to report somatic distress.

“Patients, families and health-care providers need to be made aware of these physical and emotional burdens so they can plan for post-HCT care even many years after the transplant,” Sun said.

Bhatia emphasized that their message was not to discourage patients from getting transplants, but to inform them, their families and health-care providers of potential long-term complications.

“Hematopoietic cell transplants have helped thousands of patients survive cancer and are a critical lifesaving and curative option, yet we need to be cognizant that the burden of chronic illnesses borne by these survivors is substantial,” said senior author Bhatia, who also is director of the Center for Cancer Survivorship and the BMT Long-term Follow-up Program at City of Hope.

“Regular and long-term medical surveillance after HCT is crucial to detect these complications early and decrease the burden of morbidity,” she added.