Table 3.

The median time (years) to oral cancer development and oral cancer free (OCF) rates at years 5 and 10 in the subgroup of 49 patients with high EGFR expression and evaluation of EGFR gene copy number

Variable	Level	N	Event	Median (95% CI)	OCF Rate at 5 Years (95% CI)	OCF Rate at 10 Years (95% CI)	P-value¶
	All patients	49	24	6.65 (3.52, NA)	0.62 (0.5, 0.78)	0.46 (0.32, 0.65)
Sex	Female	23	11	6.67 (2.24, NA)	0.54 (0.37, 0.8)	0.47 (0.28, 0.76)	0.737
	Male	26	13	6.65 (5.22, NA)	0.69 (0.53, 0.89)	0.46 (0.28, 0.74)
Race	Other	1	0	NA (NA, NA)			0.489
	White	48	24	6.65 (3.52, NA)	0.61 (0.49, 0.77)	0.45 (0.32, 0.64)
Histologic status	Hyperplasia	33	14	10.7 (5.22, NA)	0.68 (0.54, 0.87)	0.53 (0.36, 0.77)	0.454
	Mild dysplasia	10	6	5.09 (2.05, NA)	0.5 (0.27, 0.93)
	Moderate/severe dysplasia	6	4	4.45 (1.85, NA)	0.5 (0.22, 1)
Treatment arm	13cRA	24	13	6.21 (2.88, NA)	0.53 (0.36, 0.78)	0.41 (0.24, 0.69)	0.452
	BC + RP	18	7	10.7 (5.3, NA)	0.72 (0.54, 0.96)	0.62 (0.4, 0.94)
	RP	7	4	5.22 (2.05, NA)	0.71 (0.45, 1)
Smoking history	Current	16	5	NA (6.67, NA)	0.75 (0.57, 1)		0.471
	Former	25	15	6.21 (2.88, NA)	0.56 (0.4, 0.79)	0.39 (0.23, 0.67)
	Never	8	4	5.3 (3.36, NA)	0.6 (0.33, 1)	0.45 (0.2, 1)
Alcohol history	Current	29	12	10.7 (6.65, NA)	0.72 (0.58, 0.91)	0.56 (0.38, 0.81)	0.272
	Former	8	5	3.32 (2.27, NA)	0.47 (0.21, 1)
	Never	12	7	3.36 (1.85, NA)	0.44 (0.21, 0.92)	0.29 (0.1, 0.87)
EGFR gene copy number§	FISH-	29	8	NA (NA, NA)	0.79 (0.65, 0.95)	0.67 (0.5, 0.9)	0.0007
	FISH+	20	16	2.88 (2.05, NA)	0.4 (0.23, 0.68)	0.16 (0.05, 0.53)

Abbreviations: CI, confidence interval; NA, not applicable; 13cRA, 13-cis-retinoic acid; BC, β-carotene; RP, retinyl palmitate; EGFR, epidermal growth factor receptor.

^¶P-values are from the log-rank test (univariate analysis); FISH -: disomy; FISH+: low trisomy, high trisomy, low polysomy, or gene amplification.