Objective: To determine whether hormone replacement therapy (HRT) after treatment for breast cancer is associated with increased risk of recurrence and mortality.
Design: Retrospective observational study.
Participants and setting: Postmenopausal women diagnosed with breast cancer and treated by five Sydney doctors between 1964 and 1999.Outcome measures: Times from diagnosis to cancer recurrence or new breast cancer, to death from all causes and to death from primary tumour were compared between women who used HRT for menopausal symptoms after diagnosis and those who did not. Relative risks (RRs) were determined from Cox regression analyses, adjusted for patient and tumour characteristics.
Results: 1122 women were followed up for 0–36 years (median, 6.08 years); 154 were lost to follow-up. 286 women used HRT for menopausal symptoms for up to 26 years (median, 1.75 years). Compared with non-users, HRT users had reduced risk of cancer recurrence (adjusted relative risk [RR], 0.62; 95% CI, 0.43–0.87), all-cause mortality (RR, 0.34; 95% CI, 0.19–0.59) and death from primary tumour (RR, 0.40; 95% CI, 0.22–0.72). Continuous combined HRT was associated with a reduced risk of death from primary tumour (RR, 0.32; 95% CI, 0.12–0.88) and all-cause mortality (RR, 0.27; 95% CI, 0.10–0.73).
Conclusion: HRT use for menopausal symptoms by women treated for primary invasive breast cancer is not associated with an increased risk of breast cancer recurrence or shortened life expectancy.
- 1. Australian Institute of Health and Welfare. Cancer in Australia, 1998. Incidence and mortality data. Canberra: AIHW, 2002.
- 2. Love RR, Cameron L, Connell BL, Leventhal H. Symptoms associated with tamoxifen treatment in postmenopausal women. Arch Intern Med 1991; 151: 1842-1847.
- 3. Speroff L. Postmenopausal hormonal therapy and breast cancer. Obstet Gynecol 1996; 87: 44-54.
- 4. Roy JA, Sawka CA, Pritchard KI. Hormone replacement therapy in women with breast cancer: do the risks outweigh the benefits? J Clin Oncol 1996; 14: 997-1006.
- 5. Beckmann MW, Jap D, Djahansouzi S, et al. Hormone replacement therapy after treatment of breast cancer: effects on postmenopausal symptoms, bone mineral density and recurrence rates. Oncology 2001; 60: 199-206.
- 6. Vassilopolou-Sellin R, Zolonski C. Estrogen replacement therapy in women with breast cancer: a survey of patient attitudes. Am J Med Sci 1992; 304: 145-149.
- 7. Eden JA, Bush T, Nand S, Wren BG. A case–control study of combined continuous estrogen–progestin replacement therapy among women with personal history of breast cancer. J North Am Menopause Soc 1995; 2: 67-72.
- 8. Eden JA, Wren BG. Hormone replacement therapy after breast cancer: a review. Cancer Treat Rev 1996; 22: 335-343.
- 9. Dew J, Eden J, Beller E, et al. A cohort study of hormone replacement therapy given to women previously treated for breast cancer. Climact 1998; 1: 137-142.
- 10. Marsden J, Baum M, Sacks NPM. Hormone replacement therapy in women with previous breast cancer. Trends Endocrinol Metab 1998; 9: 32-38.
- 11. Vassilopolou-Sellin R, Asmar L, Hortobagyi GN, et al. Estrogen replacement therapy after localised breast cancer: clinical outcome of 319 women followed prospectively. J Clin Oncol 1999; 17: 1482-1487.
- 12. Natrajan PK, Soumakis K, Gambrell RD. Estrogen replacement therapy in women with previous breast cancer. Am J Obstet Gynecol 1999; 181: 288-295.
- 13. Uris-Vrèaj M, Bebar S. A case–control study of hormone replacement therapy after primary surgical breast cancer treatment. Eur J Surg Oncol 1999; 25: 146-151.
- 14. O'Meara ES, Rossing MA, Daling JR, et al. Hormone replacement therapy after a diagnosis of breast cancer in relation to recurrence and mortality. J Natl Cancer Inst 2001; 93: 754-762.
- 15. Col NF, Hirota LK, Orr RK, et al. Hormone replacement therapy after breast cancer: a systematic review and quantitative assessment of risk. J Clin Oncol 2001; 19: 2357-2363.
- 16. Peters GN, Fodera T, Sabol J, et al. Estrogen replacement therapy after breast cancer: a 12-year follow-up. Ann Surg Oncol 2001; 8: 828-832.
- 17. Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormonal therapy: collaborative reanalysis of data from 51 epidemiological studies of 52 705 women with breast cancer and 108 411 women without breast cancer. Lancet 1997; 350: 1047-1059.
- 18. Schairer C, Lubin J, Troisi S, et al. Menopausal estrogen and estrogen-progestin replacement therapy and breast cancer risk. JAMA 2000; 283: 485-491.
- 19. Ross RK, Paganini-Hill A, Wan PC, Pike MC. Effect of hormonal replacement therapy on breast cancer risk: Estrogen versus estrogen plus progestogen. J Natl Cancer Inst 2000; 92: 328-332.
- 20. Gapstur SM, Morrow M, Sellers TA. Hormone replacement therapy and risk of breast cancer with a favourable histology. Results of the Iowa women's health study. JAMA 1999, 281: 2091-2097.
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