Table 3.

Five-Year Survival Rates for Patients With Nodal Micrometastases Stratified by Number of Nodes With Metastases, Primary Tumor Thickness, and Ulceration Status

Thickness (mm) by No. of Nodes	5-Year Survival Data on Primary Tumor Ulceration						χ2	P
	Absent			Present
	No.	%	SE	No.	%	SE
1
≤ 2.00	419	87.1	2.3	103	67.8	6.2	20.6	< .001
2.01-6.00	332	74.8	3.2	362	56.9	3.4	11.3	< .001
> 6.00	26	74.8	9.9	66	35.2	9.1	2.5	.1135
2-3
≤ 2.00	115	75.4	5.6	29	50.5	12.3	3.1	.0777
2.01-6.00	116	72.0	4.8	115	57.2	4.9	7.6	.0060
> 6.00	15*			39	40.4	11.9	0.8	.3782
≥ 4
≤ 2.00	16	34.9	13.5	5	33.3	27.2	1.0	.3259
2.01-6.00	28	34.4	12.7	33	33.8	10.3	0.0001	.9934
> 6.00	2*			11	22.7	13.6	0.4	.5485

NOTE. No. of patients = 1,872.

Abbreviation: SE, standard error.

^*The 5-year survival rate cannot be estimated for these subsets because of small sample size and censoring.