Maximizing Lymph Node Dissection on Fresh and Fixed Lung Cancer Resection Specimens

Anatomic lung resection with systematic mediastinal lymph node dissection is the standard of care for patients with clinical stage I or II non-small cell lung cancer (NSCLC). While the best type of resection may sometimes be debated, it is clear that mediastinal, hilar, and lobar lymph nodes (LNs) should be routinely retrieved to achieve a complete lung cancer resection. According to major international guidelines, at least 3 hilar/intrapulmonary stations and 3 mediastinal stations should be assessed during resection. Although there is still a debate over whether the ideal number of LN stations sampled or the total number of LNs removed per station provides a better analysis, radical systematic LN dissection seems to offer the best oncological outcomes. In fact, in patients with tumors ≤4 cm in diameter completely resected, the quality of the mediastinal lymph node dissection and the thoroughness of the examination of the surgical specimen will select candidates for adjuvant treatment and define oncologic prognosis. The consequences of an incorrect lymph node classification can be substantial: while patients with N0 NSCLC have approximately 75% 5-year overall survival (OS), patients with NSCLC classified as N1 have a 5-year OS of 49%, and patients with NSCLC classified as N2 a 5-year OS of 36%. Therefore, the burden of determining the correct prognosis lies on the surgeon to perform a rigorous and thorough oncological resection, and on the pathologist to fully assess enough intrapulmonary LNs. Inaccuracy by either specialist leads to pathologic understage and suboptimal clinical management, which will lead to poor patient outcomes.

Developing a standardized technique to dissect the lobectomy specimen has the potential of maximizing the retrieval of all N1 stations lymph nodes. The investigators believe that the adoption of such technique will improve lung cancer staging and identify a higher number of patients that qualify for adjuvant therapies.