Table 3. Multivariate survival regression analysis results after PS weighting.

Covariate	Less regional LNs				More regional LNs
	HR	95% CI	P		HR	95% CI	P
Age (years)			0.001**				0.020*
<50	Reference				Reference
50–60	1.165	0.715–1.896	0.540		0.726	0.411–1.281	0.269
60–70	1.365	0.847–2.199	0.201		1.121	0.675–1.863	0.660
70–80	1.480	0.925–2.370	0.102		1.106	0.660–1.854	0.702
≥80	2.386	1.433–3.973	0.001**		1.631	0.917–2.904	0.096
Sex			0.233				0.044*
Female	Reference				Reference
Male	1.164	0.907–1.493	0.233		1.332	1.008–1.761	0.044*
Race			0.425				0.199
White	Reference				Reference
Black	1.094	0.761–1.572	0.628		1.441	0.963–2.156	0.075
Other	0.811	0.564–1.165	0.257		1.116	0.736–1.694	0.605
Grade			0.137				0.043*
Well	Reference				Reference
Moderate	1.118	0.754–1.658	0.577		1.495	0.887–2.521	0.131
Poor	1.400	0.923–2.122	0.113		1.876	1.101–3.197	0.021*
Tumor size	1.008	1.004–1.013	<0.001#		1.006	1.001–1.011	0.015*
Histology			0.097				0.077
Other	Reference				Reference
Adenocarcinoma	1.262	0.959–1.661	0.097		1.301	1.008–1.761	0.077
AJCC T, 7th			<0.001#				<0.001#
T1a	Reference				Reference
T1b	2.154	0.472–9.823	0.332		1.608	0.334–7.739	0.553
T2	2.605	0.635–10.678	0.183		1.846	0.445–7.659	0.398
T3	5.118	1.243–21.078	0.024*		6.392	1.539–26.556	0.011*
T4	8.159	1.822–36.541	0.006**		20.396	4.475–92.956	<0.001#
Non-primary surgery			0.004**				0.606
No	Reference				Reference
Yes	0.681	0.523–0.887	0.004**		0.930	0.706–1.226	0.606

*, P<0.05; **, P<0.01; ^#, P<0.001. HR, hazard ratio.