Efficacy of tyrosine kinase inhibitors in patients with non-small-cell lung cancer with performance status 4: a case series and review of the literature

BACKGROUND: Current guidelines for non-small-cell lung cancer (NSCLC) recommend that each tyrosine kinase inhibitor (TKI) is indicated even for driver mutation-positive patients with a poor performance status (PS). In previous studies, most patients had a PS of 2–3, but those with a PS of 4 were very few. Therefore, the efficacy of TKIs in patients with NSCLC with a PS of 4 remains unclear. CASE PRESENTATION: We retrospectively reviewed the clinical records of four patients with NSCLC with PS 4 treated with TKIs: an 89-year-old Japanese woman (Case 1), a 80-year-old Japanese woman (Case 2), an 50-year-old Japanese man (Case 3), and a 81-year-old Japanese woman (Case 4). Genetic alterations were epidermal growth factor receptor (EGFR), MET exon 14 skipping, BRAFV600E, and ROS1 proto-oncogene receptor tyrosine kinase (ROS1). One case with ROS1 fusion showed a significant response with the recovery of PS. However, in the remaining three cases (i.e., EGFR, MET exon 14 skipping, and BRAFV600E mutations), patients died despite the administration of TKIs. These three patients had to be hospitalized at the end of their life to receive treatment. CONCLUSIONS: This is the first case series to summarize the efficacy of TKIs in patients with NSCLC with a PS of 4. Additionally, this case series poses a question concerning the indication of TKIs for older patients with a PS of 4.