Table 2.

Effect of CSC frequency and expression of recurrence genes score on recurrence-free survival.

	Unadjusted modela			Adjusted modelb
	HR	95% CI	P-value	HR	95% CI	P-value
Expression of RG measured in CSC
Effect of +1% CSC frequency
in early-stage patients	0.99	0.78-1.24	.911	0.84	0.53-1.33	.454
in locally advanced-stage patients	1.23	1.07-1.41	.003*	1.22	1.09-1.35	.000*
Effect of −1 Ct in RG expression	1.16	0.99-1.36	.076	1.19	1.03-1.39	.021*
Expression of RG measured in cancer cells
Effect of +1% CSC frequency
in early-stage patients	1.03	0.80-1.32	.839	0.91	0.54-1.53	.728
in locally advanced-stage patients	1.27	1.10-1.48	.001*	1.25	1.09-1.44	.001*
Effect of −1 Ct in RG expression	1.12	0.99-1.26	.065	1.12	0.94-1.33	.196

The table reports the average effect of a 1% increase in CSC frequency and of an increase in recurrence genes expression (1 Ct decrease) on disease-free survival.

The unadjusted model has the following independent variables: CSC frequency (%), stage (early, locally advanced), CSC frequency × stage interaction, RG expression (Ct); ^bThe adjusted model is equal to the base model but it further adjusts for gender (male, female) and histotype (adenocarcinoma, squamous cell carcinoma).

Statistically significant at 95% confidence level (P < .05).

Abbreviations: CI, confidence interval; CSC, cancer stem cells; Ct, cycle thresholds; HR, hazard ratio.