Evidence of brain-derived neurotrophic factor in ameliorating cancer-related cognitive impairment: A systematic review of human studies.

Brain-derived neurotrophic factor (BDNF) plays an essential role in neurogenesis and neuroplasticity and may be a key protein in cancer-related cognitive impairment (CRCI). This systematic review assessed the relationship between BDNF biomarkers and neurocognitive outcomes in cancer patients and survivors. A search in PubMed, Scopus, and PsycINFO yielded 638 articles, of which 26 were eligible. Fourteen (54 %) studied BDNF protein levels while 15 (58 %) analyzed BDNF rs6265 polymorphism. Of the nine observational studies reporting BDNF plasma/serum levels, five (56 %) exhibited a positive association between BDNF and cognitive function. One study reported intra-tumoral BDNF levels that were negatively associated with memory. For rs6265, three (20 %) of 15 studies reported an association with cognitive function with inconsistent directions. Among seven neuroimaging studies, three (43 %) demonstrated an effect of BDNF on brain function and structure. These results suggest that BDNF is a potential monitoring biomarker and druggable target for CRCI.