Most of the reviews on the biological basis for symptom clusters suggest that inflammatory processes are involved in the development and maintenance of the symptom clusters. However, no studies have evaluated for associations between genetic polymorphisms and common symptom clusters (e. g., mood disturbance, sickness behavior).
Examine the associations between cytokine gene polymorphisms and the severity of three distinct symptom clusters (i.e., mood-cognitive, sickness-behavior, treatment-related) in a sample of patients with breast and prostate cancer (n=157) at the completion of radiation therapy (RT).
Symptom severity was assessed using the Memorial Symptom Assessment Scale. Symptom clusters were created using exploratory factor analysis. The associations between cytokine gene polymorphisms and the symptom cluster severity scores were evaluated using regression analyses.
Polymorphisms in C-X-C motif chemokine ligand 8 (CXCL8), interleukin (IL13), and nuclear factor kappa beta 2 (NFKB2) were associated with severity scores for the mood-cognitive symptom cluster. In addition to interferon gamma (IFNG1), the same polymorphism in NFKB2 (i.e., rs1056890) that was associated with the mood-cognitive symptom cluster score was associated with the sickness-behavior symptom cluster. Polymorphisms in interleukin 1 receptor 1 (IL1R1), IL6, and NFKB1 were associated with severity factor scores for the treatment-related symptom cluster.
Our findings support the hypotheses that symptoms that cluster together have a common underlying mechanism and that the most common symptom clusters in oncology patients are associated polymorphisms in genes involved in a variety of inflammatory processes.
Journal of pain and symptom management. 2017 Aug 07 [Epub ahead of print]
Christine Miaskowski, Yvette P Conley, Judy Mastick, Steven M Paul, Bruce A Cooper, Jon D Levine, Mitchell Knisely, Kord M Kober
School of Nursing, University of California, San Francisco, CA. Electronic address: ., School of Nursing, University of Pittsburgh, Pittsburgh, PA., School of Nursing, University of California, San Francisco, CA., School of Medicine, University of California, San Francisco, CA.