Real-world data on neoadjuvant endocrine therapy in ER-positive/HER2-negative breast cancer

Abstract

Purpose Neoadjuvant endocrine therapy (NET) has been shown to be effective in ER-positive/HER2-negative breast cancer in clinical trials. However, adoption in clinical practice is still limited. Real-world data may provide useful insights into effectiveness, toxicities and quality of care, potentially rendering clinical trial results to the real-world setting. Our purpose was to report real-world data of a cohort of postmenopausal patients submitted to NET. Methods This prospective cohort study evaluated 146 postmenopausal female patients with ER-positive/HER2-negative breast cancer treated with NET at three tertiary hospitals between 2016 and 2018. Clinicopathological information were collected prospectively. Preoperative Endocrine Prognostic Index (PEPI) score was calculated for tumors submitted to at least 16 weeks of NET. Results Median age was 67 years old, and 87.8% had stage I-II disease. Most tumors had histological grade II (76.1%). Median pretreatment Ki67 expression was 10%. Aromatase inhibitor was used in 99.5% of patients, and median treatment duration was 21.0 weeks. No tumor progressed during NET. Breast-conserving surgery was performed in the majority of patients (63.0%), as well as sentinel lymph-node biopsy (76.7%). Pathological complete response rate was 1.0%. 43 patients (29.5%) had PEPI score 0, and 26% had PEPI scores 4-5. Posttreatment Ki67 median expression was 3.0%, and only five tumors (3.4%) showed marked increase in Ki67 expression during treatment. Seven patients (4.8%) had HER2-positive residual disease, and were treated with adjuvant chemotherapy plus trastuzumab. Conclusions Our real-world data shows that NET is effective and safe in postmenopausal patients with ER-positive/HER2negative breast cancer. Postmenopausal status and low-risk luminal tumor features (luminal A-like) should be used as selection criteria to ensure the best results with NET.

The Clinical Impact of Neoadjuvant Endocrine Treatment On Luminal-Like Breast Cancers and Its Prognostic Significance: Results From a Single-institution Prospective Cohort Study

“…Only mild adverse effects were reported, and no treatment abandonment occurred, which is consistent with data from other studies. [23] In conclusion, results from our study indicate that NET can be considered a safe and effective alternative for postmenopausal women with ER+/HER2-breast cancer and that it increases the rates of BCS in both luminal A-like and luminal B-like tumors. Early changes in Ki67 proliferation rates become a feasible and reliable tool that provides crucial information about endocrine responsiveness and patient prognosis.…”

“…Although randomized NET trials, with or without other drug combinations, are numerous, real-world data, re ecting clinical practice, are scarce in this eld. [23] The aim of this study was to analyze a prospective cohort of patients in our institution who had been treated with NET and subsequently operated on, evaluating the safety (adherence and treatment tolerance) and effectiveness of NET in tumoral downstaging. Furthermore, we wanted to assess the role and clinical applicability of Ki67 changes as an indicator of endocrine responsiveness and, therefore, of NET maintenance.…”

Favorable outcome of neoadjuvant endocrine treatment than surgery‐first in female HR‐positive/HER2‐negative breast cancer patients—A NCDB analysis (2010–2016)

“… 27 In addition, some cohort studies also found that NET was well‐tolerated and achieved similar or better effectiveness. 9 , 28 , 29 , 30 Moreover, many studies based on NCDB databases hold the same views and conclusions, such as Kantor, 31 Stafford, 32 Chiba, 33 and Tamirisa. 34 While these studies unanimously support the role of NET in reducing pathological stage, axillary lymph node staging, and increasing BCS rates, they do not analyze the impact of treatment on survival prognosis.…”

“…Several studies suggested that patients with low Ki67 levels respond better to NET. 23 , 29 , 30 , 35 , 36 Prospect traffic reported that pathological response is a favorable prognostic factor following NET. 37 Additionally, other tools such as SET2,3, 38 Oncotype Dx Breast Recurrence Score, 39 and Preoperative Endocrine Prognostic Index (PEPI) 26 have been validated to predict response to endocrine therapy.…”

The Present and Future of Neoadjuvant Endocrine Therapy for Breast Cancer Treatment

“…Invasive lobular carcinoma accounts for only 15% of breast cancers, but it is known that these are usually especially responsive to NET, even though studies involving this histological subtype are scarce [ 128 ]. Only one “window of opportunity” trial focuses on the characteristics of NET in invasive lobular tumors (NCT02206984), comparing Ki67 changes and ER/PR expression after a 21-day cycle of tamoxifen or anastrozole or two doses of fulvestrant.…”