Table 3. Lymph node metastasis after three-field lymph node dissection in patients with thoracic ESCC.

Lymph node metastasis	Upper	Middle/lower	P
Total lymph node (P/N)	28/34	43/58	0.746
Supraclavicular lymph nodes (P/N)	16/46	19/82	0.291
Upper mediastinal lymph node (P/N)	15/47	21/80	0.611
Middle mediastinal lymph node (P/N)	3/59	25/76	0.001
Lower mediastinal lymph node (P/N)	1/61	9/92	0.092
Abdominal lymph node (P/N)	0/62	23/78	<0.001

ESCC, esophageal squamous cancer.