Figure 2.

Effect of phenethyl isothiocyanate (PEITC) administration on mammary carcinoma incidence and burden. Female mouse mammary tumor virus–neu mice spontaneously developed mammary tumors especially in the presence of control diets not supplemented with PEITC. Incidence and size of tumors were recorded, and tumors were resected for pathological analysis. A) Hematoxylin and eosin–stained sections depicting mammary carcinomas in representative mice fed the control or PEITC-supplemented diet (×200 magnification, scale bars = 40 µm). B) Incidence of tumors of different sizes. Results represent the mean percentage of mice with macroscopic tumors, microscopic tumors greater than 2mm² in size, and microscopic tumors less than 2mm² in size at the time that the mice were killed (after 29 weeks of PEITC treatment). P value was calculated by two-sided Fisher’s exact test. C) Relative tumor sizes. Results represent the mean tumor volumes of macroscopic tumors (mm³) and the tumor areas of microscopic tumors greater than 2mm² and microscopic tumors less than 2mm² with their corresponding 95% confidence intervals (error bars). Statistical significance of differences was determined by two-sided Student’s t tests.