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

Exploring the past, present, and future of postoperative radiotherapy for N2 stage non-small cell lung cancer

Despite conventionally applied postoperative radiotherapy (PORT) in pathological N2 (pN2) stage non-small cell lung cancer (NSCLC) considering high locoregional recurrence, its survival benefit has been a continuous topic of debate. Although several randomized clinical trials have been conducted, many of them have been withdrawn or analyzed without statistical significance due to slow accrual, making it difficult to determine the efficacy of PORT. Recently, the results of large-scale randomized clinical trials have been published, which showed some improvement in disease-free survival with PORT, but finally had no impact on overall survival. Based on these results, it was expected that the debate over PORT in pN2 patients with NSCLC would come to an end. However, since pN2 patients have different clinicopathologic features, it has become more important to carefully select the patient population who will benefit from PORT. In addition, given the development of systemic treatments such as molecular-targeted therapy and immunotherapy, it is crucial to evaluate whether there is any benefit to PORT in the midst of these recent changes. Therefore, determining the optimal treatment approach for NSCLC pN2 patients remains a complex issue that requires further research and evaluation.

The impact of postoperative radiotherapy on the survival of patients with stage III non-small cell lung cancer: A CONSORT-compliant analysis using the SEER database

BACKGROUND

Postoperative radiotherapy (PORT) is commonly used to treat patients with resected stage III non-small cell lung cancer (NSCLC), but its effectiveness remains uncertain. This retrospective cohort study aimed to investigate the impact of PORT on overall survival (OS) and evaluate its heterogeneity among subgroups of patients.

METHODS

A total of 6305 patients with resected stage III NSCLC were included in this study from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching was conducted to balance baseline characteristics between the patients who received PORT and those who did not. OS was used as the primary outcome. Subgroup analysis was performed to identify which patient subgroups might benefit more from PORT.

RESULTS

Overall, no significant difference was observed in OS between the 2 groups with or without propensity score matching. However, subgroup analysis demonstrated that PORT improved OS in patients with certain characteristics, including stage IIIA/N2, stage IIIB, squamous cell carcinoma, tumor grade III-IV, or lymph node ratio (LNR) > 1/3. Multivariate analysis showed that several variables were associated with adverse prognostic factors for OS, such as marital status (others), race (white), male gender, squamous cell carcinoma, elderly age, advanced stage, poor histological differentiation grade, high LNR, and not receiving chemotherapy.

CONCLUSION

In patients with resected stage III NSCLC, PORT may not be beneficial for all patients. However, it may improve survival time in certain patient subgroups, such as those with stage IIIA/N2, stage IIIB, squamous cell carcinoma, tumor grade III to IV, or LNR > 1/3. These findings provide important information for clinical decision-making and future research regarding the use of PORT in patients with resected stage III NSCLC.

Log odds of positive lymph nodes is a robust predictor of survival and benefits from postoperative radiotherapy in stage IIIA‐N2 resected non‐small cell lung cancer

Background

The significance of postoperative adjuvant radiotherapy (PORT) on the survival of resected IIIA‐N2 non–small cell lung cancer (NSCLC) remains controversial. Here, we aimed to determine the predictive value of the three nodal classifications which might aid in PORT decision‐making.

Methods

A total of 4797 patients with stage IIIA‐N2 resected NSCLC were identified in the Surveillance, Epidemiology and End Results (SEER) database and were grouped by whether PORT was administered. Survival analysis was used to identify the patient groups who can benefit from PORT. Multivariate analysis was performed to confirm the independent risk factors for lung cancer‐specific survival (LCSS) and overall survival (OS). A validation cohort of 1184 patients from three medical centers in China were also included.

Results

PORT was not associated with better LCSS and OS in the entire cohort after propensity score matching (PSM). However, in the subgroups of positive lymph nodes 4 (PLN4), lymph node ratio 4 (LNR4), and log odds of positive lymph nodes 4 (LODDS4), PORT exhibited its role in improving LCSS (p < 0.05). Although the three nodal classifications were all identified as independent predictors of LCSS and OS, LODDS classification had the best discriminatory ability and prognostic accuracy for stage IIIA‐N2 patients. Similar results were also obtained in the validation cohort.

Conclusions

The LODDS classification not only exhibited the best prognostic performance in predicting LCSS and OS in stage IIIA‐N2 disease, but also could help tailor individualized PORT.

Predictive Risk Factors for Early Recurrence of Stage pIIIA-N2 Non-Small Cell Lung Cancer

Purpose

Inflammatory biomarkers and clinical pathological factors have been reported to predict survival of patients with non-small cell lung cancer (NSCLC). The goal of this study was to identify risk factors for early recurrence in patients with pIIIA-N2 NSCLC who had undergone radial resection.

Methods

A retrospective analysis was conducted on 238 patients with pIIIA-N2 NSCLC who underwent surgical treatment at the First Affiliated Hospital of Wenzhou Medical University between December 2006 and August 2018. The early recurrence (ER) group included patients who recurred within one year of curative resection, while the non-early recurrence (NER) group included patients who did not recurrence or recurrence beyond one year. The univariate and multivariate Cox proportional risk analyses were used to identify prognostic factors associated with early recurrence, while the chi-square test was used for categorical data. Overall survival and recurrence-free survival were assessed by Kaplan–Meier estimates.

Results

A total of 69 patients experienced an early recurrence, while the remaining 169 patients did not relapse within one year. ER patients had a much worse prognosis than NER patients, with median survival times of 20.6 and 83.1 months, respectively. Multivariate analysis showed that smoking status, tumor size, metastatic lymph node ratio (LNR) and platelet-to-lymphocyte ratio (PLR) were independent risk factor of early recurrence. Patients with early recurrence were more likely to develop bone metastases.

Conclusion

Smoking history, large tumour size, and elevated LNR and PLR values in pIIIA-N2 NSCLC patients after complete resection may have a significant risk of early recurrence. Based on these independent risk indicators, this prediction model may successfully predict early recurrence and advise individual treatment.