Comparing anastrozole and tamoxifen in the treatment of breast cancer

This study aimed to compare anastrozole (Arimidex) and tamoxifen (Nolvadex) in the treatment of breast cancer. This study concluded that anastrozole is effective in the treatment of breast cancer. 

Breast cancer is classified into different subtypes depending on the presence or absence of certain receptors (proteins found on the surface of the cancer cells). These subtypes influence treatment options, and also directly affect disease prognosis. Hormone receptor positive cancer grows in response to female hormones such as estrogen. 

Breast cancer patients with hormone receptor positive cancers commonly receive endocrine (hormone) treatment after initial surgery or radiotherapy. This treatment can include tamoxifen or aromatase inhibitors such as anastrozole (Arimidex). It is unclear which treatment is better in terms of effectiveness or side-effects.

This study aimed to compare anastrozole to tamoxifen in breast cancer. Nine different trials with a total of 15,300 patients were included in this study. 

Anastrozole was associated with a longer disesase-free survival. On average women using anastrozole were significantly more likely to have a longer disease-free survival. Anastrozole and tamoxifen had similar overall survival. Joint pain and bone pain were side-effects commonly experienced by patients using anastrozole. Tamoxifen was associated with a higher incidence of vaginal bleeding, vaginal discharge and incidences of blood clots. 

This study concluded that anastrozole is effective in the treatment of breast cancer. 

The results in this article were not all statistically significant, but this study included randomized controlled trials which are the highest level of evidence.