The anti-estrogen drug exemestane (Aromasin) is prescribed only for breast cancer patients who have gone through menopause because it can only be given to women with suppressed ovarian function.
A group of researchers, however, wanted to compare the effectiveness of exemestane with that of the estrogen-blocking tamoxifen, which is currently the standard treatment given to premenopausal women, in preventing the recurrence of breast cancer in young women if their ovarian function is suppressed.
For their study entitled "Adjuvant Exemestane with Ovarian Suppression in Premenopausal Breast Cancer", which was presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago on June and which was also published in the New England Journal of Medicine on the same day, Olivia Pagani, from the Oncology Institute of Southern Switzerland, and colleagues involved nearly 4,700 breast cancer survivors who were 43 years old on average and who have undergone treatment to suppress the functioning of their ovaries.
The researcher randomly assigned the participants to receive either exemestane or tamoxifen and found that in five years, the cancer survival rate of the women who received exemestane was 91.1 percent while the rate in the group of women who received tamoxifen was only 87.3 percent.
The researchers also noted that the women who received exemestane had reduced risks of breast cancer recurrence by 34 percent compared with those who had tamoxifen. Those in the exemestane group also had 22 percent reduction in the odds of the cancer spreading to other parts of the body.
"In premenopausal women with hormone-receptor-positive early breast cancer, adjuvant treatment with exemestane plus ovarian suppression, as compared with tamoxifen plus ovarian suppression, significantly reduced recurrence," Pagani and colleagues wrote.
Pagani said that although their findings show that exemestane is better than tamoxifen in women with suppressed ovarian function, longer follow up on the study's participants is still needed to better assess the long term side effects of the drug as well as the survival and fertility of the women.
Breast cancer remains the most prevalent type of cancer among American women regardless of race or ethnicity. As of 2010, more than 206,000 women in the U.S were diagnosed with breast cancer. Risk factors believed to affect the odds of developing breast cancer include having a history of breast cancer in the family, smoking, having high cholesterol levels and lack of breastfeeding.
