1305P - Importance of the resected lung tumor specimen in patients with locally advanced and metastatic non-small cell lung cancer undergoing prior targeted therapy

Background

For patients who show downstaging of lung cancer following targeted therapy, salvage surgery can be considered. Resection of regrowing pulmonary masses can also be performed to acquire a tumor specimen. The aim of this study is to evaluate the prognosis of patients who have undergone prior tyrosine kinase inhibitor (TKI) treatment and later lung surgery.

Methods

The deidentified data of NSCLC patients admitted to eight university hospitals affiliated with the Catholic University of Korea were obtained from the Clinical Data Warehouse (CDW) database. Forty patients who had prior targeted therapies and later received surgical resection were evaluated for the study. The primary endpoint was overall survival, defined as the time between surgical resection and death or censoring. The secondary endpoint was postoperative progression-free survival.

Results

Of 40 patients diagnosed with adenocarcinoma. 36 (87.8%) received prior EGFR TKI treatment, while 4 (9.8%) received ALK TKI treatment. At the time of TKI initiation, 31 (77.5%) were staged as IV, and 9 (22.5%) were staged as III. Salvage surgery was performed in 18 patients (45.0%), and 22 (55.0%) underwent resection for biopsy purposes. At the time of resection, tumor burden was unchanged in 7 patients (17.5%), significantly regressing in 12 patients (30.0%), and increasing in 21 patients (52.5%). Among the 28 patients with EGFR mutations from resected tumor specimens, 9 (32.1%) exhibited the T790M mutation. Next-generation sequencing of the resected samples identified mutations such as MET amplification and TP53. Only one postoperative complication, atrial fibrillation, was observed. Patients with poor preoperative ECOG (Eastern Cooperative Oncology Group) scores had significantly worse 1-year and 2-year survival rates (P=0.014 and P=0.011, respectively). There was a significant difference in 6-month PFS rates between groups stratified by pleural invasion levels (PL0-3) (P=0.029). Furthermore, patients with T790M mutation showed a trend towards improved PFS (P=0.052).

Conclusions

Lung surgery following targeted therapies is safe and can be used to predict the prognosis of patients with initially unresectable NSCLC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.