Thanks to treatment advances, the vast majority of children diagnosed with leukemia are living well into adulthood. But the powerful treatment, while effective against the cancer, can cause some health problems later in life. A new study looked at the treatment-related effects on survivors’ mental functions.
Up to nearly 60 percent of adults who survived childhood acute lymphoblastic leukemia (ALL) had some form of cognitive impairment, the study discovered.
The types of treatment used and the age of the child at the time of diagnosis impacted the types and rates of neurocognitive difficulties experienced by the adult survivors, according to the research.
The problems affected the individual’s educational achievements and employment.
Kevin R. Krull, PhD, a researcher in the Department of Epidemiology and Cancer Control at St. Jude Children’s Research Hospital in Memphis, TN, and colleagues conducted this study to determine rates, patterns and predictors of cognitive problems in adult survivors of ALL.
Acute lymphoblastic leukemia is a blood cancer that’s diagnosed in about 3,000 children and adolescents under the age of 20 in the US every year.
The researchers identified 567 patients who had been treated for ALL 10 or more years earlier at St. Jude. The average age of participants was 33 years, and they were an average of 26 years beyond their childhood ALL diagnosis.
The researchers recorded the treatment each participant had received — cranial radiation therapy (CRT) or chemotherapy. The dosages of CRT were also noted.
Among the participants, 32.8 percent were treated with 24 units CRT, 29.5 percent with 18 units of CRT, and 37.7 percent of the children received chemotherapy only.
Participants completed comprehensive health, demographic and psychosocial surveys. They each had a risk-based medical assessment.
The neurocognitive function testing evaluated six domains: intelligence, academic skills, attention, memory, processing speed and executive function (focus, ability to switch tasks, connect past with present).
Study members also answered questions about their perceptions of their own thinking and reasoning skills.
The research team discovered the following:
- Between 28.6 percent and 58.9 percent of the participants experienced impairments across the different domains.
- Those treated with chemotherapy only demonstrated increased impairment in all domains.
- CRT-related impairments were seen at both dosages — 18 units and 24 units.
- The more years since diagnosis, the more impairment in executive function was seen.
- The younger a child was when treated with CRT, the greater the progressive impairments in intellect, academics and memory.
- Patients who had been diagnosed 45 years earlier and had been treated with 24 units of CRT had a six-fold increased risk of impaired executive function than those who weren’t treated with CRT.
- All survivors reported that behavior problems increased 5 percent for each year since diagnosis.
“This study demonstrates persistent and significant neurocognitive impairment in adult survivors of childhood ALL and warrants ongoing monitoring of brain health to facilitate successful adult development and to detect early onset of decline as survivors mature,” the researchers wrote.
Based on these findings, the authors suggested, “Ongoing services to support survivors of childhood cancer are needed as they transition into adulthood. Resources for success in higher education and vocational placement may improve this transition and future quality of life. Continued monitoring by health professionals is recommended to identify neurocognitive problems that may emerge with time. Treatment of these problems may enhance long-term maturation and quality of life."
This study was published November 4 in the Journal of Clinical Oncology.
The National Cancer Institute and the American Lebanese Syrian Associated Charities funded the research.
No conflicts of interest were reported.