Treatment Strategy of Surgical Resection With Sequential Adjuvant Chemotherapy and Radiotherapy for Patients With Stage IIIA Non-small Cell Lung Cancer and N2 Disease Only in the Subaortic or Paraaortic Level, or Both

Stage IIIA non-small cell lung cancer (NSCLC) is a very heterogeneous disease and current treatment guidelines recommend concurrent chemoradiation therapy or combined neoadjuvant chemotherapy, surgical resection, and sequential adjuvant therapy. When incidental N2 disease is found despite thorough preoperative staging, adjuvant platinum-based chemotherapy with or without adjuvant radiotherapy is recommended.

Although guidelines suggest preoperative mediastinal staging with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), this method does not allow approach of the sub- or para-aortic lymph nodes. Therefore, patients with suspected stage IIIA NSCLC and N2 disease only at the sub- or para-aortic level should undergo several processes if combined neoadjuvant chemotherapy and surgical resection is planned. First, video-assisted thoracoscopic surgery (VATS) should be performed to verify whether the sub- or para-aortic lymph nodes are involved. If a frozen-section biopsy reveals no malignant tumor involvement in the sub- and para-aortic lymph nodes, the affected lung can be resected. If there is sub- or para-aortic lymph node involvement, further neoadjuvant chemotherapy is required before surgical resection and adjuvant therapy.

Studies have shown that stage IIIA NSCLC with only sub- or para-aortic lymph node involvement has better outcomes than other stage IIIA NSCLC. Moreover, the five-year survival of patients with stage IIIA NSCLC with only sub- or para-aortic lymph node involvement is similar to that with stage II NSCLC. However, those studies were retrospective with relatively small sample sizes. Therefore, we evaluated the outcomes of combined surgical resection with adjuvant chemotherapy and radiotherapy in patients with stage IIIA NSCLC and N2 disease at only the sub- or para-aortic level.