The effect of
phenethyl isothiocyanate (
PEITC), a component of cruciferous vegetables, on the initiation and progression of
cancer was investigated in a chemically induced
estrogen-dependent
breast cancer model.
Breast cancer was induced in female Sprague Dawley rats (8 weeks old) by the administration of N-methyl nitrosourea (NMU). Animals were administered 50 or 150 µmol/kg oral
PEITC and monitored for
tumor appearance for 18 weeks. The
PEITC treatment prolonged the
tumor-free survival time and decreased the
tumor incidence and multiplicity. The time to the first palpable
tumor was prolonged from 69 days in the control, to 84 and 88 days in the 50 and 150 µmol/kg
PEITC-treated groups. The
tumor incidence in the control, 50 µmol/kg, and 150 µmol/kg
PEITC-treated groups was 56.6%, 25.0% and 17.2%, while the
tumor multiplicity was 1.03, 0.25 and 0.21, respectively. Differences were statistically significant (p < 0.05) from the control, but there were no significant differences between the two dose levels. The intratumoral capillary density decreased from 4.21 ± 0.30 vessels per field in the controls to 2.46 ± 0.25 in the 50 µmol/kg and 2.36 ± 0.23 in the 150 µmol/kg
PEITC-treated animals. These studies indicate that supplementation with
PEITC prolongs the
tumor-free survival, reduces
tumor incidence and burden, and is chemoprotective in NMU-induced
estrogen-dependent
breast cancer in rats. For the first time, it is reported that
PEITC has anti-angiogenic effects in a chemically induced
breast cancer animal model, representing a potentially significant mechanism contributing to its chemopreventive activity.