Systematic Versus Lobe-Specific Mediastinal Lymphadenectomy for Hypermetabolic Lung Cancer

Background The optimal extent of lymph node dissection (LND) for hypermetabolic tumors that are associated with high rates of nodal disease, recurrence, or mortality has not been elucidated. Methods We reviewed 375 patients who underwent lobectomy with lymphadenectomy for clinical T2–3 N0–1 M0 hypermetabolic non-small cell lung cancer (NSCLC) [maximum standard uptake value (SUVmax) ≥ 6.60] via a multicenter database. Extent of LND was classified into systematic mediastinal LND (systematic LND) and lobe-specific mediastinal LND (lobe-specific LND). Postoperative outcomes after lobectomy with systematic LND ( n = 128) and lobe-specific LND ( n = 247) were analyzed for all patients and their propensity-score-matched pairs. Results Cancer-specific survival (CSS) and recurrence-free interval (RFI) of the systematic LND group were not significantly different from those of the lobe-specific LND group in the nonadjusted whole cohort. In the propensity-score-matched cohort (101 pairs), systematic LND dissected significantly more lymph nodes (20.0 versus 16.0 nodes, P = 0.0057) and detected lymph node metastasis more frequently (53.5% vs. 33.7%, P = 0.0069). Six (5.9%) patients in the systematic LND group had a metastatic N2 lymph node “in the systematic LND field” that lobe-specific LND could not dissect. The systematic LND group tended to have better prognosis than the lobe-specific LND group (5-year CSS rates, 82.6% versus 69.6%; 5-year RFI rates, 56.6% vs. 47.3%). Conclusions Systematic LND was found to harvest more metastatic lymph nodes and provide better oncological outcome than lobe-specific LND in a cohort of hypermetabolic NSCLC patients.