Postmenopausal hormone replacement therapy: Effect on diagnosis and outcome in early-stage invasive breast cancer treated with conservative surgery and radiation

Purpose: To compare the pretreatment characteristics and outcome of postmen opausal women with stage I-II breast cancer treated with conservative surge ry and radiation who had a history of hormone replacement therapy (HRT) wit h those who had never received HRT. Materials and Methods: From 1979 ta 1993, 485 postmenopausal women underwen t excisional biopsy axillary dissection, and radiation for stage I-II breas t cancer. The median follow-up was 5.9 years. One hundred forty-one patient s reported a history of HRT. The median length of use was 5 years. three hu ndred forty-four patients reported no history of HRT. Results: Statistically significant differences between the two groups were observed for median age (HRT 60 years v no HRT 64 years; P = .0009), median weight (HRT 142 Ibs v no HRT 152 lbs; P = .004), clinical tumor size less than or equal to 2 cm (HRT 77% v no HRT 66%; P = .02), and the use of re-ex cision (HRT 62% v no HRT 49%; P = .01). The method of detection by mammogra m only (HRT 52% v no HRT 42%; P = .06) was of borderline statistical signif icance. The HRT patients had a statistically significant increased cumulati ve incidence of ipsilateral breast tumor recurrence (8% v 2%; P = .02), a s tatistically significant decreased cumulative incidence of distant metastas es(HRT 6% v no HRT 17%; P = .01), and a borderline statistically significan t improvement in cause specific survival at 10 years (HRT 92% v no HRT 86%; P = .07). Postmenopausal women with a history of HRT did not have an incre ased risk of contralateral breast cancer or second non-breast cancer malign ancy. Conclusion: This study failed to identity an adverse effect of HRT on breas t cancer mortality in patients with stage I-II disease treated with conserv ative surgery and radiation. (C) 1999 by American Society of Clinical Oncol ogy.