Adult childhood cancer survivors have high risk of cognitive impairment: JAMA

A new study by Nicholas Phillips and team showed that adult cancer survivors are more likely to have late-onset memory impairment due to modifiable risk factors that were discovered early in survival. The findings of this study were published in the Journal of American Medical Association. 

Long-term cancer survivors may be more likely to develop new neurocognitive impairment and deterioration as they become older and enter adulthood. In order to find out whether older adult childhood cancer survivors report more newly-appearing neurocognitive deficits than their siblings do, as well as to pinpoint risk variables for these impairments, this study was done.

Adult childhood cancer survivors from the Childhood Cancer Survivor research and their siblings, who served as a control group, were participants in this cohort research. The initial sample consisted of survivors for whom longitudinal neuropsychological evaluation was available and who got a diagnosis between January 1, 1970, and December 31, 1986. Between the time of the baseline assessment (23.4 years after diagnosis) and the follow-up (35.0 years after diagnosis), this study looked at the prevalence of new-onset neurocognitive impairment. The study was carried out between January 2021 and May 2022. Medical data were mined for information on cancer treatment exposures. Using Common Terminology Criteria for Adverse Events version 4.03, chronic medical problems were rated.

The main result was new-onset neurocognitive impairment (defined as a score in the bottom 10% of the sibling cohort), which was evident at follow-up but not at baseline. The Childhood Cancer Survivor Study Neurocognitive questionnaire was used to evaluate impairment.

The key findings of this study were:

The group included 2375 childhood cancer survivors, including those with acute lymphoblastic leukaemia, tumours of the central nervous system (488 people), and Hodgkin lymphoma (571 participants). 

There were 232 siblings in all. When compared to siblings, a higher percentage of survivors had new-onset memory impairment at follow-up: survivors of ALL treated with chemotherapy alone, 14.0%; survivors of ALL treated with cranial radiation (CRT), 25.8%; survivors of CNS tumors, 34.7%; and survivors of HL, 16.6%. 

In CNS tumor survivors treated without CRT, CRT was linked to new-onset memory impairment, as was alkylator chemotherapy administered to ALL survivors treated without CRT at doses more than or equivalent to 8000 mg/m2. 

The effects of CRT on newly developed memory impairment in CNS survivors were mediated by neurologic abnormalities.

Smoking, a lack of education, and a lack of physical exercise were linked to an increased chance of developing new-onset memory impairment.

Maintaining cognitive function in aging cancer survivors will need regular assessments of neurocognitive function in all survivors, including those who did not receive CNS-directed treatments, and adherence to survival late-effects screening guidelines.

Reference: 

Phillips, N. S., Stratton, K. L., Williams, A. M., Ahles, T., Ness, K. K., Cohen, H. J., Edelstein, K., Howell, R. M., Robison, L. L., Armstrong, G. T., Leisenring, W. M., & Krull, K. R. (2023). Late-onset Cognitive Impairment and Modifiable Risk Factors in Adult Childhood Cancer Survivors. In JAMA Network Open (Vol. 6, Issue 5, p. e2316077). American Medical Association (AMA). https://doi.org/10.1001/jamanetworkopen.2023.16077