title: Does tumor necrosis factor-alpha (TNF-α) play a role in post-chemotherapy cerebral dysfunction?
abstract: Post-chemotherapy treated cancer patients frequently report cognitive difficulties. The biology of this phenomenon is poorly understood, with uncertainty about possible direct toxic effects on the brain, secondary effects from systemic inflammation, host factors/genetic predisposition to cognitive complaints, or hormonal changes influencing cognitive function. To elucidate possible mechanisms associated with post-treatment cognitive dysfunction among breast cancer survivors, in 2007 we established a prospective, longitudinal, observational cohort study of early stage breast cancer patients, recruited at the end of initial treatments (primary treatment exposure included surgery, ± radiation, ± chemotherapy), and prior to the initiation of adjuvant endocrine therapy. We assessed cognitive complaints, neuropsychological (NP) test performance, markers of inflammation, and brain imaging at baseline, 6 months and 12 months after enrollment. In this analysis of data from the first 93 patients enrolled in the cohort study, we focus on the relationship of circulating levels of proinflammatory cytokines to cerebral functioning and chemotherapy exposure. Among the proinflammatory cytokines tested (IL-1 ra, sTNF-RII, CRP, and IL-6) at baseline, only sTNF-RII was increased among chemotherapy exposed patients, with a significant decline in the year after treatment (p=0.003). Higher baseline sTNF-RII in chemotherapy patients was significantly associated with increased memory complaints. In chemotherapy exposed patients, the longitudinal decline in sTNF-RII was significantly correlated with fewer memory complaints over 12 months (r=-0.34, p=0.04). Higher baseline sTNF-RII was also associated with relatively diminished brain metabolism in the inferior frontal cortex (r=-0.55, p=0.02), as well as relatively increased inferior frontal metabolism after 1 year, in chemotherapy-exposed subjects. These preliminary findings suggest that post-chemotherapy increases in TNF-α may be playing an important role in the manifestations of cognitive complaints in breast cancer survivors.
authors.affiliation: Department of Health Policy & Management, UCLA Fielding School of Public Health, Los Sangeles, CA, USA. pganz@mednet.ucla.edu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Ganz
authors.forename: J E
authors.initials: JE
authors.lastname: Bower
authors.forename: L
authors.initials: L
authors.lastname: Kwan
authors.forename: S A
authors.initials: SA
authors.lastname: Castellon
authors.forename: D H S
authors.initials: DH
authors.lastname: Silverman
authors.forename: C
authors.initials: C
authors.lastname: Geist
authors.forename: E C
authors.initials: EC
authors.lastname: Breen
authors.forename: M R
authors.initials: MR
authors.lastname: Irwin
authors.forename: S W
authors.initials: SW
authors.lastname: Cole
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects* / Q000627:therapeutic use; D001921:Brain / Q000378:metabolism*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy / Q000523:psychology / Q000628:therapy*; D003072:Cognition Disorders / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis; D003131:Combined Modality Therapy; D016207:Cytokines / Q000097:blood*; D056344:Executive Function; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000523:psychology; D008137:Longitudinal Studies; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D017741:Survivors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D014706:Verbal Learning
chemical_list: D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha