The optimal treatment of stage ⅢA-N2 non-small cell lung cancer （NSCLC） remains controversial. Resultsof primary surgery alone are not satisfied. Surgery after induction chemotherapy yields better outcomes compared to resectiononly which has been widely accepted. Randomized studies show induction chemotherapy followed by either radiotherapy or surgery have approximately equivalent survival outcomes，significant improved survival can be achieved by combined surgery in selected patients. Low-grade N2，effective response and mediastinal downstaging after induction therapy，and successful complete resection by lobectomy，are good indications of surgery. Ideal treatments are approached base on theheterogeneity of N2 . Patients with bulky or fixed N2 disease should be considered for radical chemo-radiotherapy，and surgeryshould be a part of multi-modality management for patients with non-fixed，non-bulky，single-zone N2 disease. Further randomized trials of surgery added to multi-modality management in patients with multi-zone N2 disease should be taken in order to establish possible subgroups of patients might be benefitted more from the addition of surgery.
With the boom of information technology and data science, real-world evidence (RWE) which is produced using diverse real-world data (RWD) has become an important source for healthcare practice and policy decisions, such as regulatory and coverage decisions, guideline development, and disease management. The production of high-quality RWE requires not only complete, accurate and usable data, but also scientific and sound study designs and data analyses to enable the questions of interest to be reliably answered. In order to improve the quality of production and use of RWE, China REal world data and studies ALliance (ChinaREAL) has developed the first series of technical guidance for developing real-world data and subsequent studies. The efforts are ongoing which would ultimately inform better healthcare practice and policy decisions.