Table 1.

The median time (years) to oral cancer development and oral cancer free (OCF) rates at years 5 and 10 for all patients (N=145)

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	145	35	NA (NA, NA)	0.8 (0.74, 0.87)	0.72 (0.65, 0.81)
Sex	Female	68	16	NA (NA, NA)	0.78 (0.69, 0.89)	0.73 (0.62, 0.86)	0.843
	Male	77	19	NA (NA, NA)	0.82 (0.74, 0.92)	0.72 (0.62, 0.84)
Race	Other	16	3	NA (NA, NA)	0.85 (0.67, 1)	0.75 (0.54, 1)	0.719
	White	129	32	NA (NA, NA)	0.8 (0.73, 0.87)	0.72 (0.64, 0.81)
Histologic status	Hyperplasia	97	19	NA (NA, NA)	0.85 (0.78, 0.92)	0.78 (0.7, 0.88)	0.064
	Mild dysplasia	37	11	NA (6.65, NA)	0.74 (0.61, 0.9)	0.65 (0.5, 0.85)
	Moderate/severe dysplasia	11	5	6.67 (1.85, NA)	0.61 (0.38, 1)	0.46 (0.22, 0.97)
Treatment arm	13cRA	73	18	NA (NA, NA)	0.78 (0.69, 0.89)	0.72 (0.61, 0.84)	0.565
	BC + RP	40	8	NA (NA, NA)	0.84 (0.73, 0.97)	0.8 (0.68, 0.95)
	RP	32	9	NA (6.65, NA)	0.8 (0.67, 0.96)
Smoking history	Current	51	7	NA (NA, NA)	0.87 (0.78, 0.97)	0.83 (0.72, 0.96)	0.099
	Former	58	20	NA (6.65, NA)	0.75 (0.64, 0.87)	0.62 (0.5, 0.78)
	Never	36	8	NA (NA, NA)	0.8 (0.68, 0.94)	0.76 (0.63, 0.92)
Alcohol history	Current	80	18	NA (NA, NA)	0.84 (0.76, 0.93)	0.74 (0.64, 0.86)	0.783
	Former	19	5	NA (6.21, NA)	0.78 (0.61, 1)	0.68 (0.48, 0.98)
	Never	46	12	NA (NA, NA)	0.75 (0.63, 0.89)	0.72 (0.6, 0.87)
EGFR protein expression§	low	42	6	NA (NA, NA)	0.89 (0.8, 1)	0.82 (0.69, 0.96)	0.105
	high	103	29	NA (10.7, NA)	0.77 (0.69, 0.86)	0.69 (0.6, 0.8)

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)

^§Semiquantitative evaluation; EGFR low: score 0-1 at immunohistochemistry; EGFR high: score 2-3 at immunohistochemistry