Stem Cell Transplant Patients at Greater Risk for Long-Term Health Problems

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A new study shows that survivors of hematopoietic cell transplants (HCT, which is essentially a stem cell transplant) have a higher risk of developing psychological and chronic health conditions when compared to their siblings.

These conditions include heart attack, stroke, diabetes, subsequent chronic cancers and somatic distress, pain or discomfort due to their symptoms.

Dr. Stephanie Lee, a professor at the University of Washington in Seattle and a member of the American Society of Hematology, said this may be viewed as a negative side effect of stem cell transplants – of which we've heard a lot of praise for in recent years – but "on the other hand, they (the survivors) are here to explain these complications. And, it should be viewed in that context."

The study, which was presented Saturday at the 53rd American Society for Hematology meeting, started 10 years ago when the study's authors saw the survival rate for patients with leukemia and lymphomas who used HCT as a therapeutic option was 70 to 80 percent if they survived the first two years.

"We were interested in understanding the burden of long-term morbidity in our survivors. Were they free of any complications, did they have health care needs, did they integrate fully into society?" said the study's senior author Dr. Smita Bhatia, a professor and chair of the department of population sciences at City of Hope, a comprehensive cancer center in California.

Bhatia said researchers were interested in seeing how these survivors fared versus their healthier siblings.

"We chose 10-plus year survivors because previously, studies had focused on survivors followed for a shorter period of time," Bhatia said.



HCT began as a treatment option in the mid-1970s, but didn't really gain momentum until the mid-1980s. For the procedure, patients are given chemotherapy to control the disease and then – if they can afford it – rest for a short period of time before beginning high doses of chemo and total body irrradiation to kill off their immune systems.

The study concluded that the survivors were at a higher risk for chronic health problems due to the high amounts of chemo they received – however, it has not been determined if these conditions are from the chemotherapy and radiation to control the disease or the chemotherapy and radiation used as part of the transplant process to suppress their immune systems, or a combination of both.

"Depending on the type of transplant and their primary diagnosis, cardiovascular events were more common, as well as bone necrosis and significant visual impairments," Bhatia said.

Also, brand-new cancers sometimes did occur in these patients, she noted.

Lee said she found it interesting that the rates of anxiety and depression were not different between siblings, but what was different was the rates of somatic distress.

"It's not interesting that somatic distress is more – the survivors had more issues, so despite the fact that they had different health states, there was a certain resilience to survivors," she said.

Interestingly, most of the patients studied received their transplants from siblings and not an unrelated match. However, some patients received their own stem cells back again after being extracted and treated.



Study Details

Researchers analyzed 366 people who had survived HCT 10 or more years, and their 309 siblings from the Bone Marrow Transplant Study, the largest of its kind to date.

Survivors ranged in age from 11 to 72 and they were evaluated for the presence of any chronic health condition, and a severity score (1 being mild, 5 being severe) was calculated; psychological conditions were also evaluated.

Seventy-four percent of survivors reported at least one chronic health condition over a 15-year follow-up period, compared to only 29 percent with siblings.

One-fourth of the survivors said they had a severe or life-threatening condition, compared to eight percent with siblings.

"Our goal was to utilize the findings from this study to increase awareness of the potential for long-term complications in our survivors, such that we could institute standardized methods for surveillance and early detection of these complications," Bhatia said.

For example, patients who received chest radiation followed by total body irradation can be at risk for developing breast cancer, Bhatia said, so it would be important to screen these patients with yearly mammograms and/or MRIs – to ensure early detection and possible cure.

"The issues don't end when you have a transplant," Lee said. "Physicians taking care of these patients need to be aware of these conditions because they are at higher risk of developing some of these complications."

This study is important for cancer patients contemplating whether or not to undergo a transplant, Lee noted, and also important, is the fact that it was a large-scale study.

"It was a valuable comparison – siblings often have the same socioeconomic status, same upbringing and even share some of the same genetics as the survivor," she added.