MANCHESTER, UKAn LHRH agonist (goserelin or buserelin)
plus tamoxifen (Nolvadex) provides longer survival rates than an LHRH
agonist alone in young metastatic breast cancer patients, according
to data from the Combined Hormonal Agents Trialists (CHAT) group
presented at the San Antonio Breast Cancer Symposium.
Dr. Anthony Howell, professor of medical oncology, University of
Manchester, reported results of a meta-analysis of four randomized
trials (from Japan, Italy, Zeneca, and the EORTC) comparing medical
castration with goserelin (Zoladex) or buserelin (Suprefact) plus
tamoxifen to medical castration alone. The studies evaluated the
therapies in 506 premenopausal breast cancer patients with metastatic disease.
In females, buserelin and goserelin (both approved for the treatment
of prostate cancer) act on the hypothalamic-pituitary axis to disable
the ovaries, thereby preventing the production of estrogen (ovarian
ablation). Tamoxifen reduces estrogen production by blocking estrogen receptors.
The results showed the combined endocrine treatment to be
significantly more effective than medical castration alone in terms
of response rate (39% vs 30%, P = .03); progression-free survival
(median, 8.7 vs 5.4 months, P < .001); and overall survival
(median, 2.9 vs 2.5 years, P = .02), Dr. Howell said.
The researchers performed subgroup analyses for estrogen-receptor
(ER) status, disease-free interval, and dominant metastatic site.
Although results have to be interpreted cautiously because of the
small number of patients in some of the subgroups, Dr. Howell said
that the overall results point toward a trend in overall
survival in favor of the combined treatment, and this trend was most
pronounced in the subgroups of patients with ER-positive or unknown
receptor status tumors and in those with metastasis to the bone.
Dr. Howell said that endocrine therapy may induce early menopause in
premenopausal women, but menstruation may resume after