1. Kelsey JL, Bernstein L. Epidemiology and prevention of breast cancer. Annu Rev Public Health 1996;17:47–67.
2. Hankinson SE, Willett WC, Colditz GA, et al. Circulating concentrations of insulin-like growth factor-I and risk of breast cancer. Lancet 1998;351:1393–6.
3. Poikonen P, Saarto T, Elomaa I, et al. Prognostic effect of amenorrhoea and elevated serum gonadotropin levels induced by adjuvant chemotherapy in pre-menopausal node-positive breast cancer patients. Eur J Cancer 2000;36:43–8.
4. Early Breast Cancer Trialists' Collaborative Group. Ovarian ablation in early breast cancer: overview of the randomised trials. Lancet 1996;348:1189–96.
5. Nystedt M, Berglund G, Bolund C, Fornander T, Rutqvist LE. Side-effects of adjuvant endocrine treatment in pre-menopausal breast cancer patients: a prospective randomised study. J Clin Oncol 2003;21:1836–44.
6. International Breast Cancer Study Group (IBCSG). Adjuvant chemotherapy followed by goserelin versus either modality alone for pre-menopausal lymph node-negative breast cancer: a randomised trial. JNCI 2003;95:1833–46.
7. Kaufmann M, Jonat W, Blamey R, et al. on behalf of the Zoladex Early Breast Cancer Research Association (ZEBRA) Trialists' Group. Eur J Cancer 2003;39:1711–7.
8. Early Breast Cancer Trialists' Collaborative Group. Tamoxifen for early breast cancer: an overview of the randomised trials. Lancet 1998;351:1451–67.
9. Pagani O, O'Neill A, Castiglione M, et al. Prognostic impact of amenorrhoea after adjuvant chemotherapy in pre-menopausal breast cancer patients with axillary node involvement: results of the International Breast Cancer Study Group (IBCSG) Trial VI. Eur J Cancer 1998;34:632–40.
10. Poikonen P, Saarto T, Elomaa I, Joensuu H, Blomqvist C. Prognostic effect of amenorrhoea and elevated serum gonadotropin levels induced by adjuvant chemotherapy in pre-menopausal node-positive breast cancer patients. Eur J Cancer 2000;36:43–8.
11. Davidson NE, O'Neill AM, Vukov AM, Osborne CK, Martino S, White DR, et al. Chemoendocrine therapy for premenopausal women with axillary lymph node-positive, steroid hormone receptor-positive breast cancer: results from INT 0101 (E5188). J Clin Oncol 2005;23(25):5973–82.
12. Goldhirsch A, Glick JH, Gelber RD, Coates AS, Senn HJ. Meeting highlights: international consensus panel on the treatment of primary breast cancer. seventh international conference on adjuvant therapy of primary breast cancer. J Clin Oncol 2001;19:3817–27.
13. NIH Consensus Development Panel. J Natl Cancer Inst 2001;93:979–89.
a Department of Surgery, University College London, Institute of Surgical Studies, 67–73 Riding House Street, Charles Bell House, London W1W 7EJ, United Kingdom;
b Stockholm Breast Cancer Study Group, Sweden;
c South-East Sweden Breast Cancer Group, Sweden;
d Gruppo Interdisciplinare Valutazione Interventi in Oncologia, Italy;
e Cancer Research UK & UCL Cancer Trials Centre, University College London, United Kingdom.