Dynamic changes in quality of life after three first-line therapies for EGFR mutation-positive advanced non-small-cell lung cancer

Background: Three different tyrosine kinase inhibitors have been approved as first-line therapies for epidermal growth factor receptor (EGFR) mutation-positive advanced nonsmall-cell lung cancer with similar overall survival. This study determined dynamic changes in quality of life (QoL) for patients using these therapies after controlling for potential confounders. Methods: From 2011 to 2016, we prospectively assessed the utility values and QoL scores of patients using the EuroQol five-dimension and World Health Organization Quality-of-Life-Brief questionnaires. QoL functions after initiation of treatment were estimated using a kernel-smoothing method. Dynamic changes in major determinants were repeatedly assessed for constructing mixed models. Results: A total of 344 patients were enrolled, with 934 repeated assessments. After controlling for performance status, disease progression, EGFR mutation subtype and other confounders, the mixed models showed significantly lower QoL scores for afatinib versus gefitinib in the physical, psychological and social domains, and 10 facets. The differences seemed to appear 10 months after initiation of treatment. In contrast, there was no significant difference between erlotinib and gefitinib in the scores of all domains and facets. Conclusion: QoL in patients receiving afatinib seemed to be lower than in those receiving gefitinib. Since the sample sizes in this study were relatively small, more studies are warranted to corroborate these results.