Early-onset neutropenia during perioperative chemotherapy is predictive of increased survival in patients with completely resected non-small cell lung cancer: A retrospective analysis

Background: Chemotherapy-induced neutropenia (CIN) has been found to be predictive of better therapeutic outcomes in studies of patients with various tumors. This study investigated whether CIN occurring during perioperative chemotherapy cycles 1 or 2 is a prognostic indicator in patients with completely resected non-small cell lung cancer (NSCLC). Patients and Methods: The records of patients with completely resected NSCLC receiving at least two cycles of perioperative platinum-based doublet chemotherapy were reviewed retrospectively. Early-onset CIN was defined as a neutrophil count <2.0×109/l during chemotherapy cycles 1 or 2. Subjects were stratified into two groups: presence or absence of early-onset CIN. Results: A total of 93 patients were included in this analysis. Earlyonset CIN developed in54.8% (51/93) cases. The median overall survival (OS) of patients developing early-onset CIN was significantly longer than the survival of patients without early-onset CIN (92.4 vs. 35.8 months, p=0.022), and the median disease-free survival (DFS) of patients with earlyonset CIN was also longer, although the difference was not significant (48.3 vs. 18.6 months, p=0.138). Multivariate analysis demonstrated that early-onset CIN was an independent prognostic indicator for OS [hazard ratio (HR) for death=0.422, 95% confidence interval (CI)=0.201-0.884; p=0.022] and DFS (HR for recurrence=0.482, 95% CI=0.247-0.943; p=0.033). Conclusion: Early-onset CIN during perioperative chemotherapy is predictive of better OS and DFS in patients with completely resected NSCLC.