Table 5.

Multivariate Cox Regression Analyses for Nodal Micrometastases and for Nodal Macrometastases With Mitotic Rate Data When Available

Variable	df	Nodal Micrometastases (n = 1,070)			Nodal Macrometastases (n = 268)
		χ2	P	Hazard Ratio	χ2	P	Hazard Ratio
No. of positive nodes	2	43.0	< .001		6.1	.0480
1*	—	—	—	1.00	—	—	1.00
2-3	1	2.2	.1343	1.25	0.2	.6800	1.11
≥ 4	1	43.0	< .001	3.59	5.7	.0172	1.83
Thickness, mm	3	21.4	< .001		5.7	.1267
≤ 2.00*	—	—	—	1.00	—	—	1.00
2.01-4.00	1	7.0	.0083	1.62	0.8	.3842	0.74
4.01-6.00		4.3	.0380	1.58	0.3	.5811	1.22
> 6.00	1	21.2	< .001	3.00	0.6	.4210	1.34
Ulceration	1	11.1	.001		2.8	.0959
Absent*	—	—	—	1.00	—	—	1.00
Present	1	11.1	.001	1.59	2.7	.0959	1.45
Clark level	1	0.003	.9597		0.4	.5140
II/III*	—	—	—	1.00	—	—	1.00
IV/V	1	0.003	.9597	1.01	0.4	.5140	1.27
Mitotic rate	2	23.4	< .001		2.71	.2582
< 1*	—	—	—	1.00	—	—	1.00
1-19.99	1	0.02	.8993	0.96	2.6	.1085	0.45
≥ 20	1	6.1	.0134	2.69	2.4	.1239	0.41
Age, years	2	12.7	.0018		13.8	.0010
< 50*	—	—	—	1.00	—	—	1.00
50-69	1	2.5	.1160	1.26	1.6	.2121	0.75
≥ 70	1	12.6	.0004	1.83	6.3	.0118	1.92
Site	1	5.0	.0251		0.4	.5413
Extremity*	—	—	—	1.00	—	—	1.00
Axial	1	5.0	.0251	1.36	0.4	.5413	1.13
Sex	1	1.1	.2959		0.9	.3435
Male*	—	—	—	1.00	—	—	1.00
Female	1	1.1	.2959	0.86	0.9	.3435	0.79

NOTE. No. of patients = 1,338 and includes only Stage III patients with mitotic rate grouping data (ie, < 1, 1-19, ≥ 20) available in addition to the seven variables in Table 4.

^*Reference for hazard ratio calculation.