Table 3

Multivariable logistic regression

Variable	Overall (n=1009)		Known lymphovascular space invasion status only (n=507)
Variable	HR (95% CI)	P value	HR (95% CI)	P value
Age
<50	Reference		Reference
50–69	1.89 (1.09 to 3.30)	0.02	1.22 (0.46 to 3.20)	0.69
≥70	6.70 (3.82 to 11.74)	<0.001	3.93 (1.42 to 10.9)	0.01
Adjuvant treatment
No adjuvant treatment	Reference		Reference
Chemotherapy only	0.49 (0.31 to 0.79)	0.003	0.49 (0.22 to 1.10)	0.08
Radiation only	0.82 (0.57 to 1.17)	0.27	0.76 (0.38 to 1.52)	0.44
Chemoradiation	1.26 (0.67 to 2.38)	0.47	0.96 (0.33 to 2.82)	0.94
Lymphovascular space invasion
−	Reference		Reference
+	2.09 (1.24 to 3.51)	0.006	2.44 (1.41 to 4.20)	0.001
Unknown*	0.98 (0.41 to 2.34)	0.97
Tumor size
<2 cm	Reference		Reference
≥2 cm	2.22 (0.81 to 6.05)	0.12	1.46 (0.35 to 6.14)	0.60
Unknown	1.75 (0.63 to 4.89)	0.28	0.77 (0.15 to 3.94)	0.76
Lymph node dissection
No	Reference	0.002	Reference	0.10
Yes	0.61 (0.45 to 0.84)	0.002	0.63 (0.37 to 1.09)	0.10
Comorbidity score
0	Reference		Reference
1	1.15 (0.80 to 1.65)	0.45	0.74 (0.36 to 1.51)	0.41
≥2	1.66 (0.96 to 2.87)	0.07	2.61 (1.15 to 5.94)	0.02
Facility
Non-academic	Reference		Reference
Academic	1.08 (0.80 to 1.46)	0.61	1.13 (0.67 to 1.91)	0.65
Year of diagnosis
2004–2009	Reference		–
2010–2016	0.84 (0.36 to 1.96)	0.69	–

*Lymphovascular space invasion status was not reported before 2010. Therefore, a multivariable regression model for known lymphovascular space invasion status from 2010 to 2016 is included (Online Supplemental Table 1).