Neuropsychological Symptoms and Intrusive Thoughts Are Associated With Worse Trajectories of Chemotherapy-Induced Nausea

Context: Although chemotherapy-induced vomiting is well controlled with evidence-based antiemetic regimens, chemotherapy-induced nausea (CIN) remains a significant clinical problem. Objectives: Study purposes, in a sample of outpatients with breast, gastrointestinal, gynecological, or lung cancer who received two cycles of chemotherapy (CTX, n = 1251), were to evaluate for interindividual differences in the severity of CIN and to determine which demographic, clinical, symptom, and stress characteristics are associated with higher initial levels as well as with the trajectories of CIN. Methods: Patients were recruited during their first or second cycle of CTX. Patients completed self-report questionnaires a total of six times over two cycles of CTX. Hierarchical linear modeling was used to evaluate for interindividual differences in and characteristics associated with the severity of CIN. Results: Across the two cycles of CTX, higher levels of sleep disturbance, depression, and morning fatigue, as well as higher levels of intrusive thoughts, were associated with higher initial levels of CIN. In addition, lower functional status scores and shorter cycle lengths were associated with higher initial levels of CIN, and younger age and higher emetogenicity of the CTX regimen were associated with both higher initial levels as well as worse trajectories of CIN severity. Conclusion: These findings suggest that common symptoms associated with cancer and its treatment are associated with increased severity of CIN. Targeted interventions for these symptoms may reduce the burden of unrelieved CIN.