A five classes (A-E) aggregate risk score predicting 90-day mortality after video-assisted thoracoscopic lobectomy for lung cancer, including as independent factors male sex (3 points), carbon monoxide lung diffusion capacity <60% (1 point) and operative time >150 minutes (1 point), has been recently published. This study aims to assess the effectiveness and reliability of this risk model in a large, independent cohort of patients, in order to confirm its generalizability.

From the Italian VATS Group Database, we selected patients who underwent video-assisted thoracoscopic lobectomy for non-small cell lung cancer. We calculated the aggregate risk score and the corresponding class of 90-day mortality risk for each patient. The correlation between risk classes and mortality rates was tested by Spearman's rho-test. Model calibration was evaluated by Hosmer-Lemeshow goodness-of-fit test.

Inclusion Criteria:

- Patients undergoing VATS lobectomy for non-small cell lung cancer

Exclusion Criteria:

• Incomplete data for risk score calculation
• Tumor size >5 cm
• Follow-up <3 months
• Patients undergoing neoadjuvant treatment
• Patients undergoing extended resection

All patients were selected from the Italian VATS Group registry (a database containing prospectively collected data on VATS anatomical lung resection performed in 58 certified thoracic surgery centers from January 1st 2014). The VATS Group database was awarded by the European Society of Thoracic Surgeons in the 2017