A study found that after surgery and other treatments for hormone-receptor-positive early-stage breast cancer in premenopausal women, treatment with the hormonal therapy medicine Zoladex (chemical name: goserelin) can lower the risk of the cancer coming back (recurrence) and improve overall prognosis.
The ovaries of premenopausal women produce estrogen. Estrogen can make breast cancer cells grow and increase the risk of the cancer coming back. Stopping the ovaries from producing estrogen or blocking the effects of estrogen on breast cancer cells can be an effective part of a treatment plan for premenopausal women.
Removing the ovaries (called oophorectomy or surgical ablation) or destroying the ovaries with radiation therapy permanently stop the ovaries from producing estrogen. But some premenopausal women may want to temporarily stop the ovaries from producing estrogen so they have the option of having children after treatment. Medicines called LHRH (luteinizing hormone releasing hormone) agonists can be used to temporarily stop the ovaries from making estrogen. This is called medical ovarian shutdown. LHRH-agonist medicines include Zoladex and Lupron (chemical name: leuprolide).
Tamoxifen, another hormonal therapy medicine, also can lower the risk of early-stage hormone-receptor-positive breast cancer coming back in both pre- and postmenopausal women. Tamoxifen is a SERM (selective estrogen receptor modulator). Tamoxifen has different effects on different types of cells. In breast cells, tamoxifen blocks estrogen receptors. Blocking the estrogen receptors means that estrogen can't attach to the cell and so can't tell the cell to grow.
In the study reviewed here, the researchers reviewed the information from more than 14 other studies involving more than 12,000 premenopausal women. All of the women in these studies were diagnosed with early-stage breast cancer. Almost all of the cancers were hormone-receptor-positive. To reduce the risk of the cancer coming back, the women were divided into three broad groups:
- some got Zoladex alone
- some got tamoxifen alone
- some got Zoladex and tamoxifen together
Many of the women also got chemotherapy to lower the risk of the cancer coming back. Doctors use the term adjuvant chemotherapy to describe chemotherapy used to lower the risk of the cancer coming back.
The researchers found:
- Zoladex and tamoxifen combined seemed to do a better job of reducing the risk of the cancer coming back and improving prognosis compared to Zoladex alone or tamoxifen alone.
- Zoladex alone or tamoxifen alone also reduced the risk of the cancer coming back and improved prognosis, but it wasn't clear if one medicine was more effective than the other.
- There was no difference in the risk of the cancer coming back or prognosis in women who got either Zoladex alone or tamoxifen and Zoladex together compared to women who got adjuvant chemotherapy with no hormonal therapy medicine. Still, the adjuvant chemotherapy caused more troubling side effects.
- Women who got Zoladex (either alone or with tamoxifen) and adjuvant chemotherapy had a lower risk of the cancer coming back and a better prognosis compared to women who got adjuvant chemotherapy with no hormonal therapy.
If you're a premenopausal woman diagnosed with hormone-receptor-positive early-stage breast cancer, you and your doctor will consider a number of treatment options to reduce the risk of the cancer coming back after surgery. Hormonal therapy and medical ovarian shutdown may be options you consider. Based on this study, you might want to ask your doctor if the combination of tamoxifen and Zoladex makes sense for you, whether or not you get adjuvant chemotherapy.
In the Breastcancer.org Hormonal Therapy section you can learn more about hormonal therapy medicines used to lower the risk of the cancer coming back in premenopausal women.