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 Although several randomized clinical trials have been conducted, many of them have been withdrawn or analyzed without statistical significance due to slow accrual, making it difficult to determine the efficacy of PORT.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.