Table 2.

Incidences and stages of mononuclear cell leukemia and incidences of histiocytic sarcoma in F/344N rats exposed to benzophenone in feed for 2 years

	0 ppm	312 ppm	625 ppm	1,250 ppm
Males
Mononuclear cell leukemia	27/50 a	41/50**	39/50**	24/50
# of animals surviving at end of study	22	27	31	2
# with grade 1 mononuclear cell leukemia	1	8	7	11
# with grade 2 mononuclear cell leukemia	4	8	18	2
# with grade 3 mononuclear cell leukemia	22	25	14	11
Total with mononuclear cell leukemia	27	41	39	24
Average staging grade	2.8	2.4*	2.2**	2.0**
Females
Mononuclear cell leukemia	19/50	25/50	30/50*	29/50
# of animals surviving at end of study	32	38	37	34
# with grade 1 mononuclear cell leukemia	10	13	11	10
# with grade 2 mononuclear cell leukemia	6	4	7	8
# with grade 3 mononuclear cell leukemia	3	8	12	11
Total with mononuclear cell leukemia	19	25	30	29
Average staging grade	1.6	1.8	2.0	2.0
Histiocytic sarcoma	0/50	0/50	1/50	2/50

^*Significantly different (p ≤ 0.05) from the control group by the Poly-3 test

^**p ≤ 0.01

^aNumber of animals with neoplasm per number of animals necropsied