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

Table 1 Patients characteristics n (%)

Variable	Case
Total	1490
Sex
Male	1150 (77.2)
Female	340 (22.8)
Age (yr)
≤ 58	796 (53.4)
> 58	694 (46.6)
Tumor location
Upper thoracic	181 (12.1)
Middle thoracic	831 (55.8)
Lower thoracic	478 (32.1)
Pathologic T status
T1	6 (0.4)
T2	373 (25.0)
T3	1039 (69.7)
T4a	72 (4.8)
Pathologic N
N0	727 (48.8)
N1	419 (28.1)
N2	267 (17.9)
N3	77 (5.2)
Tumor cell differentiation
Well	349 (23.4)
Moderate	727 (48.8)
Poor	414 (27.8)
Surgical approach
Left thoracotomy	917 (61.5)
Ivor-Lewis/tri-incisional	573 (38.5)
Resected lymph nodes number
≤ 14	764 (51.3)
≥ 15	726 (48.7)
Received treatment
Surgery alone	1171 (78.6)
Combined treatment	319 (21.4)

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.

Table 3 Influence of combined therapy on survival for patients with N0, N1, or N2-3 status

Factors	Surgery alone	Combined therapy
In patients with N0 status (n = 727)
No. at risk	644	83
No. of events	275	35
uHR (95%CI)	1	0.878 (0.617-1.249)
P value1		0.469
In patients with N1 status (n = 419)
No. at risk	313	106
No. of events	217	63
aHR (95%CI)	1	0.712 (0.537-0.944)
P value2		0.018
In patients with N2-3 status (n = 344)
No. at risk	214	130
No. of events	169	100
aHR (95%CI)	1	0.672 (0.521-0.867)
P value3		0.002

¹Univariate analysis;

²Multivariate 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);

³Multivariate analysis adjusted for sex, age, tumor location, pathologic T status, nodal status (N2/N3), and tumor cell differentiation. aHR: Adjusted hazard ratio; uHR: Unadjusted hazard ratio.