Table 6. Mean disease-free survival according to expression of CSC marker between stromal and epithelial tissue.

CSC marker	Mean survival time	SD	95% CI	P
Stromal ALDH-1				0.10
Negative	30.4	2.46	25.6, 35.2
Positive	60.3	2.65	55.2, 65.6
Total	60.1	2.65	54.8, 65.3
Epithelial ALDH-1				0.30
Negative	58.0	3.8	50.6, 65.4
Positive	52.4	0.6	51.1, 53.6
Total	60.1	2.6	54.9, 65.2