Table 3. Harvested lymph nodes, levels and stations.

Variables	Number
Level of lymph nodes, mean ± SD
Level N1	2.0±0.59
Level N2	3.6±1.2
Levels N1+N2	5.6±1.4
Stations of lymph nodes
N2	58 (44.6%)
N4	64 (49.2%)
N5	42 (32.3%)
N6	42 (32.3%)
N7	124 (95.4%)
N8	81 (62.3%)
N9	59 (45.4%)
N10	110 (84.6%)
N11	119 (91.5%)
N12	21 (16.2%)
Patients with N1 and/or N2 metastases	26 (20%)
Patients with unforeseen N2 disease	14 (10.8%)

N1, regional lymph nodes; N2, mediastinal lymph nodes. N2-N12 refer to the lymph node stations. The letter N is derived from Naruke’s lymph node chart.