Adjuvant therapy in patients affected by NSCLC is indicated in surgically treated cases of N2 disease, while the actual guidelines reported the possibility of a case-by-case decision in case of N1 involvement.

On the other hand, the actual categorization of patients based on the hilar or mediastinal involvement (N1 or N2) risks to be too ineffective and straightforward for prognosis prediction and an indication of adjuvant treatments. This issue was underlined in the 8th TNM proposal for the N sub-classification, with a final proposal of different subgroups based on the number of involved stations. However, the IASLC committee noted that this proposal presented some limits due overlapping or not statistical significance among some survival curves, so the proposal was not adopted in the staging system. Moreover, the committee stated that the lack of information regarding some data such as the number of the resected or the metastatic nodes might affect the results and limited other proposals.

The objectives of this study are:

• To evaluate the prognostic role of the kind of lymphadenectomy, the number of the resected and/or metastatic lymph nodes in surgically treated N positive patients in terms of survival.
• To evaluate the indication and the role of adjuvant treatments in these patients.
• To identify patients with increased risk of early recurrence or poor survival based on the lymph node involvement characteristics In particular, data will be collect in a prospective database including clinical and pathological data, kind of lymphadenectomy, number of resected nodes, number of metastatic nodes, kind and schedule of adjuvant therapy and follow-up status

Inclusion Criteria:

• Informed consent
• Age >18 years
• Non-Small Cell Lung Cancer Histology
• Anatomical lung resection (segmentectomy, lobectomy or bilobectomy, pneumonectomy)
• Pre-operative CT and PET evaluation
• Preoperative and postoperative tumour board discussion
• Intraoperative lymph node assessment (minimum 3 mediastinal stations harvested)
• Lymph node metastases

Exclusion Criteria:

• AGE < 18 years
• Pregnancy
• Psychiatric disease
• Wedge resection
• Distant metastases

patients affected by Non-Small Cell Lung Cancer underwent surgical treatment with anatomical resection + lymphadenectomy