2005

Mediastinal Lymph Node Dissection vs Lymph Node Sampling in Early-Stage Lung Cancer

The main determinant of lung cancer survival is lymph node status at the time of staging. A complete mediastinal lymph node dissection (LND) has long been the gold standard to help stage cancers. To ensure the best possible outcomes, the procedure should be performed by experienced general thoracic surgeons. In recent years, a less extensive lymph node evaluation — lymph node sampling (LNS) — has been done. LNS was advocated as an alternative approach that might have lower morbidity and mortality. However, the question of whether LNS was comparable to LND had never been formally answered.

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A multicenter analysis was conducted of 30-day postoperative data from 1,111 patients undergoing pulmonary resection. Patients were enrolled from July 1999 to February 2004 in a randomized trial comparing mediastinal LND with LNS for early-stage lung cancer. Coordinated by the American College of Surgeons Oncology Group and funded by National Cancer Institute grants, the study showed that when the surgical procedures were performed by experienced general thoracic surgeons:

• Adverse effects such as pneumonia, hoarseness, or increased chyle drainage did not occur more frequently in patients who had complete mediastinal LND compared with those who underwent LNS.
• Patient hospital stay was the same for both groups.
• Bleeding was not greater with LND than with LNS.
• Operating time was about 15 minutes longer for LND, but for a procedure that can take 2 hours, this was not considered significant.
• The operative mortality rate for lung resection in both groups was 1.4%.

Results suggest that, although LNS is a helpful staging mechanism, complete LND yields more information with greater confidence about the invasiveness of the cancer. Importantly, in the hands of experienced thoracic surgeons, LND does not represent added risk. General thoracic surgeons at Mayo Clinic in Rochester continue to use full LND and frozen-section pathology examination because of the consistently excellent outcomes.

LND is the surest way to eliminate all possibility of misreading the stage of lung cancer. Staging errors can have dire consequences for a patient, such as failure to receive appropriate postoperative chemotherapy if the cancer is staged too low as a result of limited information from an inadequate lymph node analysis.