Neoadjuvant endocrine treatment. Long term outcome of a series of patients treated at the Institut Bergonié, Bordeaux.

Abstract

Abstract Abstract #5106 Background: Endocrine treatment (NET) is an attractive alternative to chemotherapy as neoadjuvant systemic therapy for women with hormone-responsive primary breast tumors. Randomized phase III trials comparing aromatase inhibitors and tamoxifen have demonstrated that NET has the potential to render suitable for breast conservation some tumours that were too large at initial presentation. However, long term outcome is largely unknown.
 The objective of this retrospective analysis was to evaluate in clinical practice the rate of breast-conserving surgery, rate of local relapse after breast-sparing treatment, and metastasis-free survival.
 Methods: We retrospectively analyzed all women ≤ 80 years treated between 1984 and 2003 in our institute with NET for a stage II-IIIA > 30 mm estrogen [ER] and/or progesterone receptor [PR] positive, previously untreated, breast cancer. On diagnosis, all tumours were judged too large for breast-conserving treatment. Tumor response was based on clinical and radiological (mammogram and ultrasound) changes.
 Results: Characteristics of the 204 selected patients (pts) were: median age: 67.3 yrs (range 34-80) (non menopausal: 5.4%); median clinical tumor size: 4.5 (3.6-8.5) cm; median ultrasound tumor size: 2.7 (1.6-5.3) cm; 77.5% T2 and 22.5% T3; 7% invasive lobular carcinomas, 93% invasive ductal carcinomas; mSBR grade: 24% grade I, 54% grade II, 22% grade III; ER+/PR+: 58%, ER+/PR-: 33%, ER-/PR+: 9%. Most pts received tamoxifen : 178 cases (88%) vs aromatase inhibitor: 24 (12%) (other:1).
 Breast-conserving treatment could not be proposed in 96 cases (47%) because of insufficient tumour response (64 cases, 31%) or disease progression (19 cases, 9%). In 13 other cases, multifocality or diffuse microcalcifications were secondary revealed. Breast-conserving treatment could be proposed to 108 pts (53%) (58% for T2 vs 35% for T3, p=0.005). In this group, median duration of endocrine treatment before local treatment was 7.3 months (3.2-38). Patey was however performed in 7 pts because of patient choice (4 pts) or positive margins at lumpectomy (3 pts). Conserving treatment was finally performed in 101 pts (49%): lumpectomy followed by irradiation in 70 pts and exclusive irradiation in 31 pts because of contra-indication to surgery (13 pts), complete remission (13 pts) and/or patient willingness (7 pts).
 With a median follow-up of 14 years, 5-yrs and 10-yrs metastatic relapse free rate were 78% and 63%. For the subgroup of breast-conserving treatment, 5-yrs and 10-yrs local relapse free rate were 97% and 85%.
 Conclusions: NET is confirmed as being an effective neoadjuvant treatment to be discussed as an alternative to chemotherapy in cases of hormone-sensitive low-grade tumors. When endocrine therapy renders suitable breast-conserving treatment, local relapse rate is low. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5106.