Abstract
CONTEXT: Genetic variability and perceived stress have been identified as likely predictors of psychoneuroimmune (PNI) symptoms in patients with cancer. In the clinical setting, the ability to identify the patients at greatest risk of development of severe PNI symptoms continues to be elusive. OBJECTIVE: To evaluate the feasibility of cytokine genes and perceived stress scores as clinical predictors of PNI symptom severity in patients with a new diagnosis of advanced cancer compared with cancer-free controls (CFCs). DESIGN: Patients with advanced-stage cancer beginning chemotherapy and CFCs completed questionnaires at 6 time points during 24 weeks and provided blood samples for genotyping. MAIN OUTCOME MEASURES: Associations between single-nucleotide polymorphisms in cytokine genotypes and perceived stress scores with PNI symptom severity were evaluated using bivariate analysis. RESULTS: Forty-two participants were recruited (21 patients with cancer and 21 CFCs). Patients with cancer and CFCs were demographically similar and had similar allele frequencies for 15 of 16 single-nucleotide polymorphisms. Cancer-affected patients reported higher perceived stress and PNI symptom severity. Associations were found between several single-nucleotide polymorphisms and PNI symptoms, but no clear pattern emerged across time. Perceived stress was associated with PNI symptom severity for memory problems and fatigue at all 6 time points. CONCLUSION: Perceived stress performed better than cytokine genotypes as a clinical predictor of PNI symptoms in this small-scale study. Assessing perceived stress is an easy and low-cost approach that can be used to identify patients at high risk of PNI symptom development.