Early breast cancer; is long term hormone therapy necessary?

The authors aimed to assess the effectiveness of prolonged hormone therapy to treat women with early breast cancer.

Tamoxifen (Nolvadex) is a type of hormone therapy used to treat breast cancer. It attaches to the estrogen receptors (surface structures that respond to estrogen hormone) present on some cancer cells (hormone receptor positive breast cancer cells) and prevents estrogen from binding.  This hinders the stimulation of tumor growth.

Previously, 5 years of tamoxifen has been the recommended prescribed dose of this therapy. New studies, however, aim to evaluate the effects of prolonged use of this hormone therapy. 

Several studies were assessed and compared. The common aims were to evaluate the effect of the prolonged use of tamoxifen as hormone therapy to treat women with breast cancer.

Overall, prolonged tamoxifen hormone therapy (10 years) had no significant effect on the risks of developing recurrent cancer (cancer returns). According to one study, compared to the standard 5 years of tamoxifen given after primary treatment (for example, surgery), those who received the extended treatment had only a 27% decreased likelihood of developing recurrent cancer.

Furthermore, extended tamoxifen was associated with twice the risk of developing endometrial cancer (cancer that begins in the uterus or womb).

Menopause did not alter a patient’s risk of developing cancer recurrence following prolonged tamoxifen.

The authors concluded that extended tamoxifen hormone treatment did not significantly decrease the likelihood of developing recurrent cancer.

Many different studies provide opposing opinions in relation to extended tamoxifen hormone treatment. It is therefore difficult to come to a direct conclusion regarding extended tamoxifen hormone therapy for breast cancer.