Impact of genetic status on the survival outcomes of patients with clinical stage I non-small cell lung cancer with a radiological pure-solid appearance.

PURPOSE

To investigate whether genetic status is associated with the prognosis of patients with clinical stage (c-stage) I non-small cell lung cancer (NSCLC) with radiological pure-solid manifestations.

MATERIALS AND METHODS

We included 340 patients with pure-solid c-stage I NSCLC and evaluated their clinicopathological and genetic information. Disease recurrence and death were also observed at the end of the 5-year follow-up period. A Cox proportional hazards model was performed to identify the effect of clinicopathological variables, including genetic status, on oncological outcomes. Recurrence-free survival (RFS) and overall survival (OS) were calculated by Kaplan-Meier curves and were compared using log-rank tests.

RESULTS

The gene-mutation rate of c-stage I NSCLC with a radiological pure-solid appearance was 55.9% (190/340), and the frequencies of EGFR, KRAS, ALK, ROS1 and fused genes were 69.5% (132/190), 16.8% (32/190), 8.9% (17/190), 1.6% (3/190) and 3.2% (6/190), respectively. The 5-year RFS and OS rates of eligible patients were 57.1% and 76.5%, respectively. A multivariable analysis revealed that genetic status was an independent significant prognostic factor associated with RFS (hazard ratio [HR] = 1.416, 95% confidence interval [CI]: 1.020-1.964, p = 0.038) but not with OS. RFS was lower in the genetic mutation group compared with the wild-type group (p = 0.027), with 5-year RFS rate (65.7 vs. 51.6%), but the difference in OS (mutated group vs. wild-type group: 78.0% vs. 75.3%) was not statistically significant (p = 0.602). Additionally, we found that pathological nodal involvement (HR = 2.455, 95% CI: 1.745-3.454, p < 0.001 for RFS; HR = 2.204, 95% CI: 1.409-3.447, p = 0.001 for OS) was also a valuable prognostic factor in patients with pure-solid c-stage I NSCLC.

CONCLUSION

Our study provides a comprehensive description of the mutational landscape of c-stage I NSCLC, and indicates that genetic status has an impact on disease recurrence in patients with c-stage I NSCLC with pure-solid appearance.