Table 1.

The effects of aspirin or/and PEITC on lung tumorigenesis in Wistar rats treated with NNK

Group	Number of rat	Alveolar hyperplasia		Alveolar atypical dysplasia
		n	Incidence (%)	n	Incidence (%) [Decreasea]
A. Aspirin	10	6	60.00	1	10.00◆ [84.00%]
B. PEITC	10	4	40.00	1	10.00◆ [84.00%]
C. Aspirin + PEITC	10	1	10.00	0	0.00◆◆ [100.00%]
D. Positive control	8	2	25.00*	5	62.50**
E. Negative control	9	0	0	0	0

^a Compared with the incidence of alveolar atypical dysplasia in group D

*p < 0.05 when compared with negative control group by Fisher's exact probability test.

**p < 0.01 when compared with negative control group by Fisher's exact probability test.

^◆p < 0.05 when compared with positive control group by Fisher's exact probability test.

^◆◆p < 0.01 when compared with positive control group by Fisher's exact probability test.