Purpose: Between 19 and 58% of oncology patients experience chemotherapy-induced nausea (CIN). In a sample of outpatients with breast, gastrointestinal (GI), gynecological, and lung cancer, the study purposes were to evaluate for inter-individual differences in the severity of CIN over two cycles of chemotherapy (CTX) and to determine which demographic and clinical characteristics and GI symptoms were associated with higher initial levels as well as with the trajectories of CIN severity.
Methods: Patients completed study questionnaires at six time points over two cycles of CTX. These questionnaires provided information on demographic and clinical characteristics, as well as the occurrence of twelve GI symptoms. Hierarchical linear modeling based on full maximum likelihood estimation was performed.
Results: Of the 1251 patients, 47.2% reported CIN. Across two cycles of CTX, lower functional status scores and higher levels of comorbidity were associated with higher initial levels of CIN. Younger age and emetogenicity of the CTX regimen were associated with higher initial levels as well as worse trajectories of CIN. The occurrence of five GI symptoms (i.e., vomiting, lack of appetite, constipation, feeling bloated, and difficulty swallowing) was associated with higher initial levels of CIN. The occurrence of mouth sores was associated with higher initial levels as well as with worst trajectories of CIN.
Conclusions: This study is the first to identify distinct demographic, clinical, and GI symptom characteristics associated with CIN severity. These findings suggest that the etiology of CIN is complex and may warrant interventions beyond standard antiemetics.
Keywords: Antiemetics; Cancer; Chemotherapy; Gastrointestinal symptoms; Hierarchical linear modeling; Nausea.