Difference in failure patterns of pT3-4N0-3M0 esophageal cancer treated by surgery vs surgery plus radiotherapy

Table 1 Clinical and pathological characteristics of patients of the two arms, n (%)

Variable	S arm (n = 174)	S + R arm (n = 56)	P value
Sex			0.656
Male	159 (91.4)	49 (87.5)
Female	15 (8.6)	7 (12.5)
Age (yr)			0.056
<60	106 (60.9)	42 (75.0)
≥60	68 (39.1)	14 (25.0)
Pathological differentiation			0.586
Poor	66 (37.5)	1 (1.8)
Moderate	97 (55.7)	33 (58.9)
Well	10 (5.7)	22 (39.3)
Tumor location			0.031a
Upper	15 (8.6)	3 (5.4)
Middle	98 (56.3)	22 (39.3)
Lower	61 (35.1)	31 (55.4)
Lymph node dissection			0.448
2-field resection	139 (79.9)	49 (87.5)
3-field resection	28 (16.1)	7 (12.5)
No. of LNs involved			0.740
≤2	113 (64.9)	35 (62.5)
≥3	61 (35.1)	21 (37.5)
No. of LNs dissected			0.569
<12	2 (1.1)	1 (1.8)
≥12	172 (98.9)	55 (98.2)
T stage			0.075
T3	164 (94.3)	48 (85.7)
T4	10 (5.7)	8 (14.3)
Chemotherapy			0.978
Yes	106 (60.9)	34 (60.7)

^aP < 0.05. S arm: Surgery alone arm; S + R arm: Surgery + postoperative radiotherapy arm; LN: Lymph node.