Hormone therapy an effective alternative to chemotherapy for young women

Results from two landmark studies, just published in the latest issue of the Journal of Clinical Oncology, show that hormonal treatment with goserelin (Zoladex), alone or in combination with the anti-oestrogen tamoxifen, is an effective alternative to standard chemotherapy for younger women with hormone-sensitive, early breast cancer.< Professor Christobel Saunders, Professor of Surgical Oncology at UWA, Sir Charles Gairdner and Royal Perth Hospitals, said these findings had important implications for around 1500 young Australian women who are diagnosed each year with hormone-sensitive early breast cancer. “I believe there will now be a paradigm shift in the treatment of young women with oestrogen receptor positive breast cancer,” Professor Saunders said. “For pre-menopausal women with oestrogen receptor positive breast cancer, the standard of care should now be ovarian ablation either with goserelin, surgery or radiotherapy, plus tamoxifen.” She said there was still a tendency in Australia to treat younger women with breast cancer with chemotherapy. While the two studies just published used older chemotherapy regimens, there was no evidence as yet to suggest that newer chemotherapy agents would be superior to goserelin plus tamoxifen. Dr Nicholas Wilcken, Medical Oncologist at Westmead and Nepean Hospitals, Sydney said the studies showed that for some pre-menopausal women, goserelin may be just as good as chemotherapy without the debilitating side effects. “The role of hormonal treatments has probably been a little underestimated in the past, but now if women were being treated with chemotherapy we would also add in a hormonal agent such as goserelin or tamoxifen,” Dr Wilcken said. “For some women hormonal treatment will be an alternative to chemotherapy, however for others chemotherapy will still have a very important role in their treatment.” Chemotherapy kills cancer cells while the hormonal agent goserelin suppresses the ovaries’ supply of oestrogen that stimulates the cancer cells to grow. Both chemotherapy and goserelin may result in an early menopause, however, in the majority of women the effect with goserelin is reversible once treatment is completed. Tamoxifen also prevents oestrogen from stimulating cancer cell growth by blocking the oestrogen receptors in the cancer cells. The Austrian Breast and Colorectal Study Group study (AC05), involved 1099 patients and compared a combination of goserelin (three years) and tamoxifen (five years) with six cycles of standard chemotherapy in premenopausal women with hormone-sensitive tumours. 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. As a result of the different modes of action of the treatments, the numbers of patients suffering from the typical side effects of chemotherapy were all substantially higher in the chemotherapy group compared with the goserelin-treated patients. Both treatments were associated with menopausal symptoms, however as expected, the incidence of menopausal symptoms was initially higher in the goserelin-treated group, these disappeared in the majority of patients one year post-therapy. However the numbers reporting side effects post-chemotherapy remain virtually unchanged. The second study gave further weight to the role of goserelin in early breast cancer. It is well known that the efficacy of goserelin in advanced breast cancer is enhanced by the addition of tamoxifen. The AC05 study has shown that this is also true for early breast cancer. After following patients up for five years, the Austrian researchers have found that relapse-free survival and local recurrence-free survival were significantly better in the goserelin plus tamoxifen group compared with the chemotherapy group and that a similar positive trend was seen for the hormone therapy group in terms of overall survival. Goserelin is now approved for the treatment of early breast cancer in Australia. However, the PBS currently only reimburses goserelin for use in advanced breast cancer.