Voluntary exercise inhibits intestinal tumorigenesis in Apc Min/+mice and azoxymethane/dextran sulfate sodium-treated mice

Table 1 Effect of voluntary exercise on intestinal tumor formation in Apc ^Min/+ mice maintained on AIN93G diet or a high-fat^a

Group (N)	Small intestinal tumors							Colon tumors
	Region			Size			Total
	Proximal	Middle	Distal	≤1 mm	1–2 mm	≥ 2 mm
Experiment 1 on AIN93G diet (5 – 11 wk of age)
Control (27)	7.9 ± 1.4	-	21.3 ± 3.3	-	-	-	29.2 ± 4.4	0.6 ± 0.2
Exercise (28)	4.5 ± 0.9^c	-	15.7 ± 3.0	-	-	-	20.2 ± 3.8^b	0.4 ± 0.1
Experiment 2 on High-fat diet (5 – 14 wk of age)
Control (19)	4.0 ± 0.4	12.1 ± 1.7	14.7 ± 2.0	18.0 ± 2.4	8.1 ± 1.3	4.8 ± 0.6	30.8 ± 3.4	0.6 ± 0.2
Exercise (19)	2.7 ± 0.3^c	7.3 ± 1.6^c	12.0 ± 1.4	15.3 ± 1.9	4.4 ± 0.9^c	2.3 ± 0.4 ^d	22.0 ± 2.8^c	0.4 ± 0.1

^a Results of Experiments 1 and 2. In Experiment 1, the small intestine was divided into two segments (proximal and distal), and the tumor size was not scored because the majority of tumors in 11-week-old mice were ~1 mm in diameter. The number of mice was accumulated from 4 identical experiments that were done with smaller numbers of mice per group. Data were then combined and analyzed through a statistical adjustment; the effects of two factors, treatment (exercise) and experiment, as well as the interaction of treatment and experiment, on the response variable, total small intestinal tumor numbers (square-rooted to stabilize the variance), were initially assessed by two-way ANOVA; factors found not to affect the response variable significantly were excluded in the final statistical analyses. ^bA statistically significant treatment (exercise) effect was found (p < 0.05). In Experiment 2, the small intestine was divided into three segments (proximal, middle and distal), and the tumor size was scored Each value represents mean ± SE of number of mice (N). ^c: p ≤ 0.05 by two-tailed t-test;^d: p < 0.005 by two-tailed t-test.

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