PLNR≤20% may be a benefit from PORT for patients with IIIA-N2 NSCLC: a large population-based study

The impact of EGFR mutation and PD-L1 status on the efficacy of postoperative radiotherapy in stage III-pN2 NSCLC

BACKGROUND

The role of postoperative radiotherapy (PORT) for patients with completely resected stage III-pN2 non-small-cell lung cancer (NSCLC) remains controversial. PORT is not routinely recommended for patients with completely resected stage III-pN2 NSCLC. Therefore, identifying the population that could benefit from PORT is urgently needed.

METHODS

We retrospectively enrolled 251 patients with completely resected stage III-pN2 NSCLC at our institution between 2018 and 2023. The Kaplan-Meier curves and log-rank tests were used to analyze disease-free survival (DFS) and overall survival (OS). Risk factors were identified using univariate and multivariate Cox regression analyses. The cumulative incidence rates of locoregional recurrence (LRR) were calculated via competing risk analyses and compared using the Gray test.

RESULTS

A total of 251 patients were enrolled in the study, with the median follow-up of 24.9 months. Among overall patients, 61 patients underwent PORT, and 190 patients did not. Although patients in the PORT group exhibited a trend toward longer DFS, the difference was not statistically significant (median DFS: 39.1 vs. 35.5 months; HR 0.58, 95% CI 0.35-0.97; p = 0.072). Subgroup analyses revealed that PORT significantly prolonged DFS both in EGFR wild-type patients (median DFS: 35.3 vs. 18.3 months; HR 0.33, 95% CI 0.17-0.62; p = 0.002) and in PD-L1 positive patients (median DFS: 35.3 vs.16.4 months; HR 0.35, 95% CI 0.16-0.74; p = 0.029). In contrast, no significant DFS or OS benefits were observed in EGFR mutant patients or PD-L1 negative patients. Furthermore, PORT was associated with the significantly lower risk of LRR in overall patients (HR 0.39, 95% CI 0.16-0.97; p = 0.043), EGFR wild-type patients (HR 0.25, 95% CI 0.09-0.68; p = 0.007), and PD-L1 positive patients (HR 0.15, 95% CI 0.03-0.70; p = 0.016). PORT did not confer a locoregional control benefit in EGFR mutant patients (HR 0.58, 95% CI 0.07-4.58; p = 0.61) or PD-L1 negative patients (HR 1.02, 95% CI 0.27-3.82; p = 0.98).

CONCLUSION

For patients with completely resected stage III-pN2 NSCLC, PORT significantly improves DFS and reduces the risk of LRR in EGFR wild-type patients or PD-L1 positive patients. The EGFR and PD-L1 status may serve as biomarkers to identify the population that could benefit from PORT.

The efficacy of postoperative radiotherapy in resected pⅢA-N2 EGFR mutant and wild-type lung adenocarcinoma

The resected pⅢA-N2 non-small-cell lung cancer (NSCLC) patients who could benefit from postoperative radiotherapy (PORT) are not well-defined. The study explored the role of PORT on EGFR mutant and wild-type NSCLC patients. We retrospectively searched for resected pIIIA-N2 lung adenocarcinoma patients who underwent EGFR mutation testing. 80 patients with EGFR wild-type and 85 patients with EGFR mutation were included. 62 patients received PORT. In overall population, the median disease-free survival (DFS) was improved in PORT arm compared to non-PORT arm (22.9 vs. 16.1 months; p = 0.036), along with higher 2-year locoregional recurrence-free survival (LRFS) rate (88.3% vs. 69.3%; p = 0.004). In EGFR wild-type patients, PORT was associated with a longer median DFS (23.3 vs. 17.2 months; p = 0.044), and a higher 2-year LRFS rate (86.8% vs. 61.9%; p = 0.012). In EGFR mutant patients, PORT was not significantly correlated with improved survival outcomes. EGFR wild-type may a biomarker to identify the cohort that benefits from PORT.

Postoperative radiotherapy for patients with completely resected pathological stage IIIA-N2 non-small cell lung cancer: a preferential benefit for squamous cell carcinoma

BACKGROUND

The beneficial effect of postoperative radiotherapy (PORT) on completely resected pathological IIIA-N2 (pIIIA-N2) non-small cell lung cancer (NSCLC) has been a subject of interest with controversy. The aim of the study was to distinguish the clinical efficacy of PORT on lung adenocarcinoma (LADC) and lung squamous cell carcinoma (LSCC) among pIIIA-N2 NSCLC.

PATIENTS AND METHODS

Between October 2010 and September 2016, 288 consecutive patients with completely resected pIIIA-N2 NSCLC at Beijing Chest Hospital were retrospectively analyzed, which consisted of 194 cases of LADC and 85 cases of LSCC. There were 42 (21.6%) patients treated with PORT in LADC cases and 19 (22.3%) patients treated with PORT in LSCC cases. The 5-year overall survival (OS), loco-regional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) were calculated using the Kaplan-Meier method. The prognostic factors were determined using Cox's regression model.

RESULTS

Among 194 cases of LADC, the 1-, 3-, and 5-year OS in the PORT group were 95.2%, 61.9% and 40.0%, respectively, while in the non-PORT group were 90.1%, 63.3% and 45.0% (p = 0.948). The use of postoperative chemotherapy (POCT) and smoking index ≥ 400 were both prognostic factors of 5-year rates of OS, LRFS and DMFS. On the other hand, among 85 cases of LSCC, the 1-, 3-, and 5-year OS in the PORT group were 94.7%, 63.2% and 63.2%, respectively, whereas in the non-PORT group were 86.4%, 48.5% and 37.1% (p = 0.026). In this group, only the use of PORT was a favorable prognostic factor for 5-year OS, LRFS and DMFS.

CONCLUSIONS

Due to clinicopathological differences among completely resected pIIIA-N2 NSCLC, PORT may not be suitable to all patients. Our study distinguishes pIIIA-N2 LSCC from LADC by their positive responses to PORT.

A biomarker-based prediction model for risk of locoregional recurrence in pathologic stage IIIA-N2 non-small cell lung cancer

OBJECTIVE

To investigate risk factors for locoregional recurrence (LRR) of pathologic stage IIIA-N2 non-small cell lung cancer (pIIIA-N2 NSCLC) and construct a prediction model for risk score to determine a patient's risk for LRR and guide the selection of postoperative radiotherapy (PORT).

METHODS

The clinical, pathologic, and biological data of 107 patients with pIIIA-N2 NSCLC treated at Fujian Provincial Hospital between May 2012 and December 2018 were analyzed retrospectively. None of the patients had positive surgical margins, and none received preoperative treatment or PORT. The Kaplan-Meier method was used for a univariate analysis of possible factors for locoregional recurrence-free survival (LRFS). The Cox regression model was used in a multivariate analysis to identify independent risk factors for LRFS, which were used to construct a prediction model for risk score. The concordance index was calculated to evaluate discrimination.

RESULTS

The median follow-up time was 31.2 months. During the follow-up, 69 (64.5%) patients had LRR and/or distant metastasis (DM). Among them, 46 (43%) patients had LRR (with or without DM), and 56 (52.3%) patients had DM (with or without LRR). The 1-year LRFS, distant metastasis-free survival, disease-free survival, and overall survival rates were 78.2%, 78%, 69.8%, and 90.2%, respectively; the 3-year rates were 50.6%, 41.2%, 31.2%, and 66.3%, respectively. Multivariate analysis showed that surgical approach (hazard ratio [HR], 0.348; 95% confidence interval [CI], 0.175-0.693; P = 0.003), metastatic N2 lymph node ratio (HR, 3.597; 95% CI, 1.832-7.062; P = 0.000), epidermal growth factor receptor status (HR, 3.666; 95% CI, 1.724-7.797; P = 0.001), and lymphocyte-to-monocyte ratio (HR, 2.364; 95% CI, 1.221-4.574; P = 0.011) were independent risk factors for LRFS. These independent risk factors were used to construct a prediction model for risk score and stratify patients into the low-risk group (risk score: 0-2), medium-risk group (risk score: 3-5), and high-risk group (risk score: 6-13). The 1-year LRFS rates of these groups were 91.9%, 85.3%, and 54.6%, respectively; the 3-year LRFS rates were 71.4%, 57.3%, and 13.6%, respectively. These between-group differences were significant (P = 0.000). The prediction model showed good discrimination (concordance index = 0.747, 95% CI, 0.678-0.816).

CONCLUSION

Our prediction model for risk score based on characteristics of pIIIA-N2 NSCLC patients may help clinicians predict a patient's risk for LRR. Further investigations of PORT with patients in different risk groups are warranted.

Combining node location and node ratio as a prognostic factor for surgical resected non-small cell lung cancer: a population-based study

Background

In the TNM system only the anatomic location is used to define nodal status. In this study we aim to evaluate the effectiveness of combining the location and ratio of metastatic lymph node (pN-NR) for the prognosis of non-small cell lung cancer (NSCLC).

Methods

Patients with pN1/pN2 NSCLC were retrieved from the SEER database. The optimal cut point of NR was determined with the maximal selecting test. All patients were divided into 4 categories with combination of pN (pN1 or pN2) and NR (low or high). The pN-NR was investigated as a predictor of overall survival (OS) and cause-specific survival (CSS) using Cox regression models. Survival curves were plotted using the Kaplan-Meier method and the difference was compared with log-rank test.

Results

A total of 12,170 patients were enrolled. The optimal cut point of NR was 0.3. Patients were divided into 4 groups: pN1-NR <0.3, pN1-NR ≥0.3, pN2-NR <0.3 and pN2-NR ≥0.3. The pN-NR was an independent prognostic factor for survival. Compared with pN1-NR <0.3, the hazard ratio of OS was 1.405 (95% CI: 1.295-1.524), 1.183 (95% CI: 1.113-1257) and 1.717 (95% CI: 1.607-1.835) times higher for pN1-NR ≥0.3, pN2-NR <0.3 and pN2-NR ≥0.3 group, respectively. The survival curves of OS separated well between the 4 pN-NR groups, with 5-year OS 47.1% for pN1-NR <0.3, 43.0% for pN2-NR <0.3, 35.0% for pN1-NR ≥0.3 and 28.5% for pN2-NR ≥0.3, and the P value between neighboring curves was statistically significantly. The same trend was observed for CSS. Subgroup analysis revealed similar results except the pneumonectomy group.

Conclusions

pN-NR could be a good predictor for the prognosis of NSCLC.

Postoperative radiotherapy option based on mediastinal lymph node reclassification for patients with pN2 non-small-cell lung cancer

Background

In this research, we used the mediastinal lymph node reclassification proposed by the International Association for the Study of Lung Cancer (iaslc) to screen for patients with pathologic N2 (pN2) non-small-cell lung cancer (nsclc) who might benefit from postoperative radiotherapy (port).

Methods

The study enrolled 440 patients with pN2 nsclc who received complete surgical resection and allocated them to one of three groups: N2a1 (single-station skip mediastinal lymph node metastasis), N2a2 (single-station non-skip mediastinal lymph node metastasis), and N2b (multi-station mediastinal lymph node metastasis). Rates of local recurrence at first recurrence in patients receiving and not receiving port were compared using the chi-square test. Overall (os) and disease-free survival (dfs) were then compared using Kaplan-Meier survival analysis with log-rank test. In addition, the factors potentially influencing os and dfs were analyzed using univariate and multivariate Cox regression.

Results

The rate of local recurrence for the N2a2 and N2b groups was significantly lower in patients receiving port (p = 0.044 and p = 0.043 respectively). The log-rank test revealed that, for the N2a1 group, differences in os and dfs were not statistically significant between the patients who did and did not receive port (p = 0.304 and p = 0.197 respectively). For the N2a2 group, os and dfs were markedly superior in patients who received port compared with those who did not (p = 0.001 and p = 0.014 respectively). For the N2b group, os was evidently better in patients who received port compared with those who did not (p = 0.025), but no statistically significant difference in dfs was observed (p = 0.134). Multivariate regression analysis revealed that, in the N2a1 group, port was significantly associated with poor os [hazard ratio (hr): 2.618; 95% confidence interval (ci): 1.185 to 5.785; p = 0.017]; in the N2a2 group, port was associated with improved os (hr: 0.481; 95% ci: 0.314 to 0.736; p = 0.001) and dfs (hr: 0.685; 95% ci: 0.479 to 0.980; p = 0.039).

Conclusions

For patients with pN2 nsclc who receive complete resection, port might be beneficial only for patients with single-station non-skip metastasis (N2a2). Patients with single-station skip metastasis (N2a1) and multi-station metastasis (N2b) might not currently benefit from port.