Hormone therapy is effective alternative to chemotherapy.

2003 FEB 13 - (NewsRx.com & NewsRx.net) -- Results from two landmark studies, both published in the Journal of Clinical Oncology, show that hormonal treatment with goserelin (Zoladex), alone or in combination with the antiestrogen tamoxifen, is an effective alternative to standard chemotherapy for younger women with hormone-sensitive, early breast cancer.

For these women, chemotherapy is currently the accepted treatment approach following initial surgery.

Chemotherapy kills cancer cells by direct action while the hormonal agent goserelin suppresses the supply of estrogen from the ovaries, which stimulates the cancer cells to grow. Tamoxifen also prevents estrogen from stimulating cancer cell growth by blocking the estrogen receptors in the cancer cells. Effectively cutting off the cancer's supply of estrogen provides an alternative method of combating the disease that avoids the harrowing side effects of chemotherapy. Many women are worried by the short-term side effects of chemotherapy such as hair loss, severe nausea and vomiting, and the risk of life-threatening infection, but not all are aware that chemotherapy can result in an early menopause.

The two studies published involved over 2700 patients. ZEBRA was the largest study ever undertaken to compare hormonal therapy with standard chemotherapy and involved 1640 pre- and perimenopausal women with early breast cancer from 102 centers, in 15 countries, who were randomized to receive either a monthly injection of goserelin for 2 years (n=817) or a standard chemotherapy regimen lasting 6 months (n=823). The second study, AC05, involved 1099 patients and compared a combination of goserelin (3 years) and tamoxifen (5 years) with 6 cycles of standard chemotherapy in premenopausal women with hormone-sensitive tumors.

In the ZEBRA study, goserelin was shown to be as effective as standard chemotherapy in preventing recurrence of the cancer in the hormone-sensitive group of patients (60% of all premenopausal breast cancers are hormone-sensitive). As a result of the different modes of action of the treatments, the number of patients suffering from the typical side effects of chemotherapy e.g. hair loss, nausea and vomiting (despite use of anti-emetics in over 97% of the patients) and infection were all substantially higher in the chemotherapy group compared with the goserelin-treated patients (45% vs. 4%, 58% vs. 5% and 13% vs. 5% respectively).

Both treatments were associated with menopausal symptoms, such as vaginal dryness and hot flushes. However, while as expected, the incidence of menopausal symptoms was initially higher in the goserelin-treated group, (vaginal dryness: 26% vs. 15%; hot flushes: 74% vs. 44%, respectively), these disappeared in the majority of patients one year post-therapy, whereas, the numbers reporting side ...