Cold exposure and capsaicin promote 1,2-dimethylhyrazine-induced colon carcinogenesis in rats correlates with extracellular matrix remodeling

Table 1 Incidence of various tumors induced in different treatment groups

Group	Total number of tumors	Adenoma incidence, %			Adenocarcinoma incidence, %				With lymphytic metastasis (%)
		Mild	Moderate	Severe	Well-differentiated	Moderate-differentiated	Poor-differentiated	Mucinous	Metastasis rate
Control	-	-	-	-	-	-	-	-	-
DMH	23	2/23 (8.7)	2/23 (8.7)	3/23 (13)	12/23 (52.2)	4/23 (17.4)	3/23 (13.0)	-	-
Cold exposure	38	1/38 (2.6)	2/38 (5.3)	3/38 (7.8)	5/38 (15.8)b	8/38 (21.1)	15/38 (36.8)a	4/38 (10.5)	20.0
Capsaicin	34	2/31 (5.9)	1/34 (2.9)	4/31 (12.9)	7/31(22.6)a	12/31 (38.7)	7/31(22.6)	1/31 (3.2)	-

Values are expressed as the proportion of lesions-bearing rats. n = 10 rats/group. Incidence data was analyzed by using chi-square or Fisher’s exact test.

^aP < 0.05.

^bP < 0.01.

1,2-dimethylhyrazine compared with cold exposure and capsaicin-treated group. DMH: 1,2-Dimethylhyrazine.