The relative efficacy of neoadjuvant endocrine therapy vs chemotherapy in postmenopausal women with ER- positive breast cancer

Abstract

519 Background: Neoadjuvant chemotherapy (NACT) or hormonal therapy (HT) is being used increasingly to downstage locally advanced and large operable breast cancer. Following this treatment, inoperable breast cancer often becomes fully resectable, and tumors requiring mastectomy may be successfully removed by breast-conserving surgery (BCS). Patient selection is important to optimize neoadjuvant therapy (NAT), especially in elderly postmenopausal women with co-morbid conditions. Methods: Between March 1998 and March 2003, 121 postmenopausal (PM) women with ER(+) and/or PgR(+) breast cancer (BC) T2N1–2, T3N0–1, T4N0M0 assigned NAT with either CT Dox 60 mg/m2 + Pac 200 mg/m2, every 3 weeks, 4 cycles, n=62 patients (pts), or HT with aromatase inhibitors, anastrazole 1 mg, n = 30 pts, 3 months). The primary endpoint was to compare overall objective response (OR) determined by clinical (palpation) and mammogr. Secondary endpoint was the number of pts who qualified for BCS + radiotherapy (50 Gy for 25 fractions). Results: Table 1. OR rate (clinical and mammogr.) was statistically similar ( p > 0.05 ) in the CT and anastrazole groups. Tendency to more BCS took place in the anastrozol arm that in the CT arm ( 37.9 % vs 20.6 % p=0.054). Local recurrence rate were similar for pts receiving CT or HT (3,2 % and 3,4%, at 34 months median follow up ). In CT arm the most frequent grade III/IV toxicity was alopecia ( 79.3 5 ), neutropenia ( 43.1 %), cardiotoxicity (6.8 %), diarrhea (1.7%). HT was well tolerated. The most commonly adverse events were hot flushes (23.3%), vaginal discharge (6.6%), musculosskeletal disorders (1.7%). Conclusions: NAHT with aromatase inhibitors (anastrazole) is a reasonable alternative to CT for PM women with ER and/or PgR - positive cancer in clinical situation where the low toxicity of the regimen is considered an advantage, for example, for women over 70. No significant financial relationships to disclose.