Prognostic Impact of Postoperative Recurrence in Patients With Epidermal Growth Factor Receptor-Positive Non-Small Cell Lung Cancer.

BACKGROUND

Mutations in the epidermal growth factor receptor (EGFR) gene are the most common targetable gene alterations in non-small cell lung cancer (NSCLC). In Japan, approximately 40% of patients who undergo surgical resection for non-squamous NSCLC have EGFR mutations. However, no long-term studies have been conducted including a large number of EGFR-positive NSCLC patients with postoperative recurrence (PR).

METHODS

We conducted a retrospective observational study of the data of EGFR-positive NSCLC patients with PR who had undergone surgery at the Shizuoka Cancer Center between October 2002 and November 2017. We evaluated post-recurrence overall survival (PRS) and postoperative overall survival (POS) using the Kaplan-Meier method and identify any associations between the clinical variables at recurrence and PRS using univariate and multivariate analysis.

RESULTS

We enrolled 162 patients. The median observation time for PRS was 4.95 years (range, 0.82-13.25) and POS was 5.81 years (range, 2.84-16.71). The median PRS was 5.17 years (95% confidence interval [CI], 3.90-5.61) and POS was 7.07 years (95% CI, 5.88-8.01). Univariate analysis identified male sex (median PRS: 3.32 vs. 5.39 years; p < 0.05), bone metastasis (median PRS: 2.43 vs. 5.33 years; p < 0.05), and central nervous system (CNS) metastasis (median PRS: 3.05 vs. 5.39 years; p < 0.05) and multivariate analysis identified bone metastasis (hazard ratio [HR], 2.01; 95% CI, 1.23-3.28; p < 0.05) and CNS metastasis (HR, 1.84; 95% CI, 1.14-2.98; p < 0.05) as poor prognostic factors. The pattern of recurrence (oligo vs. non-oligo recurrence) was not a prognostic factor. Logistic regression analysis revealed the association between sex and the presence bone/CNS metastasis at recurrence.

CONCLUSION

Our data may help visualize future prospects and determine the timing of osimertinib initiation. New treatment strategies need to be developed for patients with bone/CNS metastasis at the first recurrence.