Table 2.

Risk factors for recurrence-free survival

Parameter	Univariate		Multivariate
	HR (95% CI)	p value	HR (95% CI)	p value
Adjuvant chemotherapy	0.457 (0.251–0.831)	0.010	0.408 (0.221–0.754)	0.004
Yes (n = 127)
No (n = 158)
Age	1.216 (0.639–2.314)	0.551
≥ 60 yr (n = 216)
< 60 yr (n = 69)
Sex	1.765 (1.013–3.076)	0.045	1.635 (0.934–2.865)	0.086
Male (n = 146)
Female (n = 139)
Adenocarcinoma	1.408 (0.725–2.735)	0.313
Yes (n = 237)
No (n = 48)
Tumor diameter	1.627 (0.938–2.822)	0.083	1.384 (0.740–2.590)	0.309
> 3.0 cm (n = 81)
≤ 3.0 cm (n = 204)
Smoking history	1.542 (0.897–2.649)	0.117	1.174 (0.656–2.100)	0.590
Yes (n = 110)
No (n = 175)
Visceral pleural involvement	0.834 (0.356–1.950)	0.675
Yes (n = 258)
No (n = 27)
Micropapillary	1.543 (0.880–2.705)	0.130	1.522 (0.848–2.733)	0.159
Yes (n = 79)
No (n = 206)
Lymphatic invasion	1.388 (0.753–2.558)	0.293
Yes (n = 63)
No (n = 222)
Vascular invasion	2.121 (0.999–4.504)	0.050	2.561 (1.171–5.601)	0.018
Yes (n = 26)
No (n = 259)

The multivariate analysis was conducted using a backward elimination procedure for variables with p < 0.2 in the univariate analysis. In univariate analysis, adjuvant chemotherapy, age, sex, histology, tumor diameter, smoking history, and high-risk factors were analyzed.

HR, hazard ratio; CI, confidence interval.