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FP01 - Early Stage/Localized Disease (ID 111)
- Event: WCLC 2020
- Type: Posters (Featured)
- Track: Early Stage/Localized Disease
- Presentations: 1
- Coordinates: 1/28/2021, 00:00 - 00:00, ePoster Hall
FP01.02 - The Efficacy of Postoperative Radiotherapy in IIIA-N2 Non-Squamous NSCLC with Different EGFR Mutation Status: A Retrospective Analysis (ID 3680)
00:00 - 00:00 | Author(s): Chaoyuan Liu
The effect of postoperative radiotherapy (PORT) on completely resected IIIA-N2 non-squamous non-small cell lung cancer (NSCLC) remains controversial. Growing postoperative therapies for epidermal growth factor receptor (EGFR)-mutant patients make the role of PORT ambiguous. Previous in-vitro studies have indicated that the status of EGFR mutation status can influence the radio-sensitivity of lung cancer, which needs more clinical investigation to verify. In this retrospective study, we aim to assess the efficacy of PORT in IIIA-N2 non-squamous NSCLC with different EGFR mutation status.Methods
We enrolled patients who were diagnosed with completely resected stage IIIA-N2 non-squamous NSCLC, receiving postoperative radiotherapy or not, between April 2011 and May 2017 from the Second Xiangya Hospital and Hunan Cancer Hospital. And we analyzed the influence of PORT on disease-free survival (DFS) and overall survival (OS) in NSCLC patients with different EGFR mutation status.Results
In total, 124 patients were eligible. The median follow-up time was 43.2 months (range 6-103 months). In multivariate analysis, age (＞60 years old), cycles of chemotherapy (＜4) and multiple-station N2 metastasis were correlated with shorter DFS. Multiple-station N2 metastasis，wild-type EGFR and no PORT were independent risk factors for OS. PORT significantly improved OS (46.40 months vs. 34.17 months, P = 0.021) but not DFS (19.02 months vs. 17.23 months, P = 0.266). In the EGFR wild-type group, PORT prolong OS (43.20 months vs. 28.67 months, P = 0.007), especially in EGFR wild-type group with multiple-station N2 metastasis (39.73 months vs. 24.9 months, P = 0.006) rather than DFS (18.43 months vs. 17.77 months, P = 0.775). There was a trend that PORT improved OS (69.30 months vs. 49.97 months, P = 0.057) and DFS (21.17 months vs. 17.17 months, P = 0.075) in the EGFR-mutant group, although there was no significant difference. In EGFR-mutant patients with multiple-station N2 metastasis, the DFS was significantly prolonged (23.13 months vs. 14.10 months, P = 0.021) in the PORT group. Nevertheless, the OS (72.5 months vs. 60.63 months, P = 0.189) and DFS (13.7 months vs. 24.33 months, P = 0.664) were not improved in EGFR-mutant patients with single-station N2 metastasis(Figure 1).
Comparison of overall survivall (A,C,E) and disease-free survival (B,D,F) between the PORT and the non-PORT group. PORT=postoperative radiotherapy.
It is necessary for stage IIIA-N2 non-squamous NSCLC patients to receive PORT，especially for EGFR wild-type patients. Meanwhile, PORT can reduce local recurrence and metastasis in EGFR-mutant group, particularly in EGFR-mutant patients with multiple-station N2 metastasis. More prospective studies are needed to clarify the role of PORT in the EGFR-mutant IIIA-N2 non-squamous NSCLC patients.