Table II.

Effects of I3C and MI on VC-induced microscopic pulmonary lesions in A/J mice^a

Group	Carcinogen	Chemopreventive agent (dose, μmol/g diet)	No. of mice	Hyperplastic foci per mouse	Adenoma per mouse	Adenoma with cellular pleomorphism per mouse	Adenocarcinoma per mouse
1	VC	—	21	1.7 ± 1.6	4.6 ± 2.1	3.5 ± 1.6	0.6 ± 0.8
2	VC	I3C (70)	20	2.0 ± 1.7	3.6 ± 1.8	1.9 ± 1.5**	0.2 ± 0.5*
3	VC	I3C (30)	20	1.9 ± 1.5	4.6 ± 2.3	2.5 ± 1.8**	0.5 ± 0.6
4	VC	MI (56)	20	2.3 ± 1.5	2.2 ± 1.6**	2.1 ± 1.2**	0.6 ± 0.7
5	None	None	10	None	None	None	None

*P = 0.04; **P < 0.0001, compared with group 2.

^aFor the assessment of pulmonary tumor multiplicity and types of proliferative lesions, three step sections having 4 μm thickness were cut and stained with hematoxylin and eosin. Proliferative lesions were counted in each step section and the total number of each type of lesion per mouse was expressed as an average number of each lesion per section (sum of each lesion in three step sections divided by three). Proliferative lesions in the lungs were classified as hyperplastic foci, adenoma or adenocarcinoma based on recommendations published by the Mouse Models of Human Cancers Consortium [Nikitin et al., (24)].