Objective: Dose delays and reductions in chemotherapy due to hematologic toxicities are common among patients with advanced non-small cell lung cancer (NSCLC). However, limited data on behavioral or psychological predictors of chemotherapy adherence exist. The goal of this study was to explore the frequency and clinical predictors of infusion dose delays and reductions in this patient population.
Methods: Fifty patients newly diagnosed with advanced NSCLC of high performance status (Eastern Cooperative Oncology Group Performance Status=0-1) completed baseline assessments on quality of life (Functional Assessment of Cancer Therapy - Lung) and mood (Hospital Anxiety and Depression Scale) within 8 weeks of diagnosis. Participants were followed prospectively for 6 months. Chemotherapy dosing data came from medical chart review.
Results: All patients received chemotherapy during the course of the study, beginning with a platinum-based doublet (74%), an oral epidermal growth factor receptor-tyrosine kinase inhibitor (14%), or a parenteral single agent (12%). Forty percent (n=20) of patients had a dose delay (38%) and/or reduction (16%) in their scheduled infusions. Fisher's Exact Tests and regression analyses showed that patients who experienced neutropenia, smoked at the time of diagnosis, or reported heightened baseline anxiety were significantly more likely to experience dose delays or reductions. There were no associations between chemotherapy adherence and patient demographics, performance status, or quality of life.
Conclusion: In this sample, more than one third of patients with advanced NSCLC experienced either a dose delay or reduction in prescribed chemotherapy regimens. Behavioral and psychological factors, such as tobacco use and anxiety symptoms, appear to play an important role in chemotherapy adherence, though further study is required to confirm these findings.