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

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.

Predictive Value of Clinicopathological Factors to Guide Post-Operative Radiotherapy in Completely Resected pN2-Stage III Non-Small Cell Lung Cancer

Introduction: With the evolution of radiotherapy techniques and a better understanding of clinicopathological factors, we aimed to evaluate the treatment effect of post-operative radiotherapy (PORT) and associated predictive factors in patients with completely resected pN2 stage III non-small cell lung cancer (R0 pN2-stage III NSCLC). Material and Method: The cancer registration database of a single medical center was searched for R0 pN2-stage III NSCLC. Clinicopathological factors and information about post-operative therapies, including PORT and adjuvant systemic treatment, were retrospectively collected and analyzed. The Kaplan-Meier method and a Cox regression model were applied for time-to-event analysis, with disease-free survival (DFS) being the primary outcome. Results: From 2010 to 2021, 82 R0 pN2-stage III NSCLC patients were evaluated, with 70.1% of tumors harboring epidermal growth factor receptor mutations (EGFR mut.). PORT was performed in 73.2% of cases, and the median dose was 54 Gy. After a median follow-up of 42 months, the 3-year DFS and overall survival (OS) rates were 40.6% and 77.3%, respectively. Distant metastasis (DM) was the main failure pattern. In the overall cohort, DFS was improved with PORT (3-year DFS: 44.9% vs. 29.8%; HR: 0.552, p = 0.045). Positive predictive factors for PORT benefit, including EGFR mut., negative extranodal extension, positive lymphovascular invasion, 1-3 positive lymph nodes, and a positive-to-dissected lymph node ratio ≤0.22, were recognized. OS improvement was also observed in subgroups with less lymph node burden. Conclusions: For R0 pN2-stage III NSCLC, PORT prolongs DFS and OS in selected patients. Further studies on predictive factors and the development of nomograms guiding the application of PORT are highly warranted, aiming to enhance the personalization of lung cancer treatment.

Role of skip N2 lymph node metastasis for patients with the stage III-N2 lung adenocarcinoma: a propensity score matching analysis

PURPOSE

Recent studies have indicated some differences in the prognosis of patients with stage III-N2 lung adenocarcinoma, and the prognosis of patients with skip N2 lymph node metastasis (SKN2) is good. This study grouped patients with stage III-N2 lung adenocarcinoma by propensity score matching (PSM) to evaluate the impact of SKN2 on the prognosis of these patients.

METHODS

The clinical data for patients who underwent radical lobectomy and had a postoperative pathological diagnosis of stage III-N2 lung adenocarcinoma at our centre from 2016 to 2018 were collected, and PSM was performed at a ratio of 1:1.

RESULTS

A total of 456 patients were enrolled in this study. After PSM, 112 patients were included in the SKN2 group, and 112 patients were included in the non-SKN2 group. When comparing the SKN2 group with the non-SKN2 group, the 3-year OS rate was (71.4% vs. 12.5%, p < 0.001), and the 3-year DFS rate was (35.7% vs. 5.4%, p < 0.001). It is further divided into four groups:single-station SKN2 (N2a1),Multi-station SKN2 (N2a2),single-station non-SKN2 (N2b1) and Multi-station non-SKN2 (N2b2).The 3-year OS and DFS rates of skip lymph node metastasis were better than those of non-skip lymph node metastasis(OS:N2a1 vs. N2b1 68.4% vs. 23.5%,p < 0.001;N2a2 vs. N2b2 73.0% vs. 7.7%,p < 0.001)(DFS:N2a1 vs. N2b1 68.4% vs. 5.9%,p < 0.001;N2a2 vs. N2b2 62.2% vs. 5.1%,p < 0.001), regardless of the number of N2 station(OS:N2a1 vs. N2a2 68.4% vs. 73.0%,p = 0.584;N2b1 vs. N2b2 23.5% vs. 7.7%,p = 0.051). On multivariate analysis, sex (p = 0.008) ,Vascular tumour thrombus(p = 0.047),size(p = 0.002)and SKN2 (p < 0.001) were independent predictors of OS.

CONCLUSION

For patients with stage III-N2 lung adenocarcinoma, the prognosis of SKN2 patients is better than non-SKN2 patients', and SKN2 may be used as an important factor in the N2 subgroup classification in future TNM staging.

[Review for N2 Sub-staging in Non-small Cell Lung Cancer]

Patients with N2 non-small cell lung cancer (NSCLC) were heterogeneous groups and required further stratification. The International Society for the Study of Lung Cancer (IASLC) divided N2 into three sub-stages: N2 at a single station without N1 involvement (N2a1), N2 at a single station with N1 involvement (N2a2), and N2 at multiple stations (N2b). These new descriptors significantly distinguished the overall survival (OS), disease-free survival (DFS), and recurrence pattern of patients with different N2 sub-stages. The OS and DFS of N2a1 were not sufficiently distinguished from N1 at multiple stations (N1b). The OS and DFS of N2a2 were intermediate between those of N2a1 and N2b. Current evidence did not support the further subdivision of the N2b. The main recurrence pattern of N2a1, N2a2 and N2b were distant metastasis, and the risks of distant metastasis increased successively. N2a1 patients were at low risk of locoregional recurrence, which could not be reduced by postoperative radiotherapy (PORT). N2a2 and N2b patients had a similar higher risk of locoregional recurrence, which could be reduced to a similar level of N2a1 patients by PORT.
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The efficacy of postoperative radiotherapy for patients with non-small cell lung cancer: An updated systematic review and meta-analysis

The controversy over the efficacy of postoperative radiotherapy (PORT) has existed for a long time. The present study reassessed the overall survival (OS) and disease-free survival (DFS) data to investigate whether PORT can improve survival in resectable non-small cell lung cancer (NSCLC) patients. The following databases were used to perform literature search: PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Embase (from January 1, 1986 to July 5, 2021). The results of overall survival (OS) and disease-free survival (DFS) were calculated as hazard ratio (HR). Confidence intervals are chosen with 95% confidence intervals. A total of 12 RCTs and 19 retrospective cohort studies were found to meet the inclusion criteria. A significant DFS improvement was detected in the PORT group (4111 patients from 15 studies), although statistical difference was not detected for OS between the non-PORT and PORT groups (31 studies, 49,342 total patients). PORT prolonged OS in patients undergoing PORT plus postoperative chemotherapy (POCT) and in pN2 patients. Patients with a median radiation dose of 50.4 Gy and a median radiation dose of 54 Gy had a better OS after PORT. However, if the total radiotherapy dose went up to 60 Gy, PORT increased the risk of death in NSCLC patients. Significant difference in OS was not found in the results of studies with regard to treatment methods, pathologic stages, study type, radiation beam quality, and radiation dose. Patients undergoing postoperative chemoradiotherapy and pN2 patients can benefit from PORT. Patients exposed to median radiation doses of 50.4 and 54 Gy demonstrated relatively good efficacy. For patients with non-small-cell lung cancer, PORT has not been proven to extend OS, but its effect on DFS remains strong.

The effect of adjuvant chemoradiotherapy on survival after R0 resection for stage III-N2 nonsmall cell lung cancer: A meta-analysis

BACKGROUND

Adjuvant chemotherapy is still the standard treatment for stage III-N2 nonsmall cell lung cancer after R0 resection, and it is still controversial whether conventional adjuvant radiotherapy is needed. We used meta-analysis to try to answer whether adjuvant postoperative chemoradiotherapy (POCRT) can bring survival benefits to patients with stage III-N2 nonsmall cell lung cancer after R0 resection.

METHODS

Up to June 25, 2021, the databases of PubMed, Embase, Cochrane Library, CNKI, and Wanfang were searched, and clinical studies on POCRT for stage III-N2 nonsmall cell lung cancer were included. RevMan5.4 software was used for meta-analysis.

RESULTS

A total of 8959 patients were included in 5 randomized controlled trials and 17 retrospective studies. The results of the meta-analysis showed that POCRT could improve 3 and 5 years overall survival (OS) rate (OR = 1.52, 95%CI: 1.05-2.20; OR = 1.30, 95%CI: 1.16-1.46), 3 and 5 years disease-free survival (DFS) rate (OR = 1.34, 95%CI: 1.01-1.76; OR = 1.74, 95%CI: 1.43-2.12), and 5-year locoregional recurrence-free survival (LRFS) rate (OR = 2.69, 95%CI: 1.76-4.11) in patients with stage III-N2 nonsmall cell lung cancer compared with adjuvant postoperative chemotherapy (POCT) alone. But could not improve 5-year distant metastasis-free survival (DMFS) rate (OR = 1.14, 95%CI: 0.52-2.52). The results of subgroup analysis showed that postoperative sequential chemoradiotherapy could improve the 3 and 5 years OS rate (OR = 2.06, 95%CI: 1.22-3.46; OR = 1.39, 95%CI: 1.21-1.59). Three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) can improve the 3 and 5 years OS rate (OR = 1.80, 95%CI: 1.09-2.99; OR = 1.31, 95%CI: 1.04-1.66). In addition, POCRT could improve the 3-year OS rate (OR = 1.88, 95%CI: 1.21-2.92) in patients with N2 single-station lymph node metastasis compared with POCT alone.

CONCLUSION

Compared with POCT alone, adjuvant POCRT can significantly improve the overall survival rate of patients with NSCLC after R0 resection of stage III-N2, especially in patients with N2 single-station lymph node metastasis. Accurate radiotherapy techniques such as 3DCRT or IMRT are recommended, and postoperative sequential chemoradiotherapy is the best treatment mode.

The Impact of Skip vs. Non-Skip N2 Lymph Node Metastasis on the Prognosis of Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Objective: The skip N2 metastases were frequent in non-small-cell lung cancer (NSCLC) and the better prognosis of NSCLC with a skip over non-skip N2 lymph node metastases is controversial. The primary aim of this study is to investigate the prognosis effect of skip N2 lymph node metastases on the survival of NSCLC.

Setting: A literature search was conducted in PubMed, EMBASE, and Cochrane Library with the term of “N2” or “mediastinal lymph node” or “mediastinal nodal metastases”, and “lung cancer” and “skip” or “skipping” in the title/abstract field. The primary outcomes of interests are 3- and 5-year survival in NSCLC.

Participants: Patients who underwent complete resection by lobectomy, bilobectomy, or pneumonectomy with systemic ipsilateral lymphadenectomy and were staged as pathologically N2 were included.

Primary and Secondary Outcome Measures: The 3- and 5-year survival of NSCLC was analyzed. The impact of publication year, number of patients, baseline mean age, gender, histology, adjuvant therapy, number of skip N2 stations, and survival analysis methods on the primary outcome were also analyzed.

Results: A total of 21 of 409 studies with 6,806 patients met the inclusion criteria and were finally included for the analysis. The skip N2 lymph node metastases NSCLC had a significantly better overall survival (OS) than the non-skip N2 NSCLC [hazard ratio (HR), 0.71; 95% CI, 0.62–0.82; P < 0.001; I² = 40.4%]. The skip N2 lymph node metastases NSCLC had significantly higher 3- and 5-year survival rates than the non-skip N2 lymph node metastases NSCLC (OR, 0.75; 95% CI, 0.66–0.84; P < 0.001; I² = 60%; and OR, 0.78; 95% CI, 0.71–0.86; P < 0.001; I² = 67.1%, respectively).

Conclusion: This meta-analysis suggests that the prognosis of skip N2 lymph node metastases NSCLC is better than that of a non-skip N2 lymph node.