Comparative effects of tamoxifen versus anastrozole in an experimental mammary carcinogenesis model

Abstract EN

Tamoxifen and anastrozole are key agents in the treatment of breast cancer.

In the present study, the effect of tamoxifen (0.6 mg / kg / day orally) versus anastrozole (3 mg / kg / day orally) given for 28 days, was investigated in the 7, 11 dimethylbenzanthracene rat mammary carcinogenesis model.

Results of the present study showed that, after 4 weeks of treatment, both drugs were able to reduce the percentage increase in tumor volume compared to the control.

Moreover, anastrozole was able to arrest the increase in tumor volume.

Both tamoxifen and anastrozole were able to increase the serum insulin-like growth factor-1 (IGF-1).

In addition, tamoxifen reduced serum malondialdehyde (MDA) while anastrozole increased it.

Tamoxifen also induced tumor apoptosis while anastrozole did not.

In conclusion, the antioxidant activity and the ability to induce apoptosis could be contributing factors to the antitumor action of tamoxifen.

Anastrozole use in the treatment of breast cancer is associated with oxidative stress and the effect of its use combination with antioxidants should be investigated.

Both tamoxifen and anastrozole increase serum IGF-1 which raises the option of investigating their effect in breast cancer in association with drugs which antagonize IGF-1 action