Symptom clusters and their predictors in patients with lung cancer and treated with programmed cell death protein 1 immunotherapy

OBJECTIVE: The aims of this study were to examine the symptom severity and interference among patients with lung cancer treated with PD-1 immunotherapy, explore whether those symptoms were clustered together, and identify factors associated with symptom clusters. METHODS: A cross-sectional study was conducted. Data were collected by demographic and clinical characteristic questionnaires and the M.D. Anderson Symptom Inventory Lung Cancer Module. Symptom clusters were identified using exploratory factor analysis, and stepwise linear regression was applied to analyze the factors affecting the symptom clusters. RESULTS: A total of 148 patients with lung cancer treated with PD-1 immunotherapy participated in this study. The overall symptom burdens of these patients were mainly at a mild level. The patient symptom clusters identified in this study were a general cluster, a treatment-related cluster, a pulmonary cluster, a gastrointestinal cluster, and a neural cluster. The patients’ Karnofsky performance status (KPS) score (β ​= ​−2.758, P ​< ​0.001) and having a history of chemotherapy (β ​= ​4.384, P ​= ​0.001) were significant predictors of the general cluster. Their KPS scores (β ​= ​−1.202, P ​< ​0.001) and having a history of chemotherapy (β ​= ​−1.957, P ​= ​0.001) were significant predictors of the pulmonary cluster. Their monthly income (β ​= ​−0.316, P ​= ​0.030) and KPS scores (β ​= ​−0.357, P ​= ​0.045) were significant predictors of the gastrointestinal cluster. Having a history of chemotherapy (β ​= ​1.868, P ​< ​0.001) was the predictor of the neural cluster. CONCLUSIONS: The symptom burdens of patients with lung cancer and treated with PD-1 immunotherapy were at a mild level and appeared to be clustered. In addition, because the symptoms that comprise a cluster are interrelated, the diagnosis and management of each symptom in a cluster should not be performed in isolation, and each symptom in a cluster should be treated either simultaneously or in an orderly manner.