Aggressive surgical resection does not improve survival in operable esophageal squamous cell carcinoma with N2-3 status

Table 2 Influence of surgical parameters on survival for patients with N0, N1, and N2-3 status

Factors	Surgical approach		Resected lymph nodes (n)
	Left transthoracic	Ivor-Lewis/tri-incisional	≤14	≥15
In patients with N0 status (n = 727)
No. at risk	445	282	391	336
No. of events	204	106	215	95
aHR (95%CI)	1	0.632 (0.499-0.801)	1	0.478 (0.375-0.609)
P value1		< 0.001		< 0.001
In patients with N1 status (n = 419)
No. at risk	254	165	219	200
No. of events	183	97	174	106
aHR (95%CI)	1	0.661 (0.516-0.847)	1	0.464 (0.364-0.592)
P value1		0.001		< 0.001
In patients with N2-3 status (n = 344)
No. at risk	218	126	154	190
No. of events	170	99	127	142
uHR (95%CI)	1	0.826 (0.644-1.058)	1	0.849 (0.668-1.078)
P value2		0.130		0.179

¹Multivariate analysis adjusted for sex (male/female), age (≤ 58/> 58 years), tumor location (upper/mid/lower), pathologic T status (T1/T2/T3/T4a), and tumor cell differentiation (well/moderate/poor);

²Univariate analysis. aHR: Adjusted hazard ratio; uHR: Unadjusted hazard ratio.