Reduced memory before breast cancer treatment associated with specific cytokine
Pretreatment cytokine levels, specifically soluble TNF receptor type two (sTNF-RII), are associated with reduced memory performance among newly diagnosed patients with post-menopausal breast cancer prior to receipt of surgery and/or adjuvant therapy. This study was published in the JNCI: Journal of the National Cancer Institute (2015; doi:10.1093/jnci/djv183).
Neurocognitive dysfunction was associated with pro-inflammatory cytokines among breast cancer survivors in a previous report, and was attributed to chemotherapy effects. However, it is not clear if these associations exist even prior to treatment.
Previous studies in breast cancer have defined pretreatment as prior to adjuvant therapy but after surgical resection, but because cytokine levels can be altered following surgery, Sunita K. Patel, PhD, from the Departments of Population Sciences and Supportive Care Medicine, at the City of Hope Medical Center and Beckman Research Institute in Duarte, CA, and colleagues, measured cytokines (sTNF-RII, Interleukin-6 [IL-6], and Interleukin-1 receptor antagonist [IL-1ra]) in plasma from 174 patients with newly diagnosed breast cancer before any treatment, including surgery. Comprehensive neuropsychological evaluations were also performed. Age-matched control subjects without cancer were evaluated as the comparison group.
They observed that memory performance was reduced in patients versus controls. In adjusted analysis, an association was seen between higher sTNF-RII and reduced memory performance among patients with breast cancer but not cancer-free control subjects.
“Previous studies demonstrating an association between inflammatory markers and cognition have attributed the association to cancer treatment, but our results suggest these links could be attributed to factors other than cancer treatment, possibly to factors that contribute towards the cancer diagnosis,” concluded the authors.
In an accompanying editorial (JNCI 2015; doi:10.1093/jnci/djv176), Carissa A. Low, PhD, Pawel Kalinski, MD, PhD, and Dana H. Bovbjerg, PhD, from the University of Pittsburgh Cancer Institute in Pittsburgh, PA, discussed the importance of the findings and briefly reviewed data on additional behavior symptoms not explored in the study.
They concluded the results suggest future studies are needed that “will improve basic scientific understanding of how activation of proinflammatory cytokine networks by cancer cells may increase behavioral symptoms and will also guide clinical interventions to reduce these cancer-related symptoms and improve patient quality of life.”