Current Status of Extended Adjuvant Endocrine Therapy in Early Stage Breast Cancer

Abstract

Opinion statementIn the past decade, several endocrine treatment regimens have been developed for the adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer, including tamoxifen, aromatase inhibitors (AI), or a combination of these. The standard duration of adjuvant endocrine treatment has been 5 years for a long time. Nevertheless, the high number of recurrences occurring after 5 years suggested that extended endocrine therapy could further improve outcome, which led to the start of several randomized clinical trials investigating the effects of extended use of endocrine therapy. The extended duration of tamoxifen has been shown to improve disease-free survival and overall survival in the ATLAS and aTTom trials. However, in postmenopausal women, AIs have been shown to be more effective when compared with tamoxifen. Based hereon, it is recommended that adjuvant endocrine therapy in postmenopausal women with early breast cancer should include an AI. Recently, the DATA, IDEAL, and NSABP B42 trials showed that extended adjuvant endocrine therapy with AIs beyond 5 years in postmenopausal women with early breast cancer did reduce the occurrence of secondary breast tumors, but had no or only a small impact on distant metastasis free survival. Furthermore, toxicity of adjuvant AIs led to gradually decreasing compliance rates and long-term toxicities to non-breast cancer-related deaths. Therefore, we suggest considering extended adjuvant treatment only in women with high-risk early breast cancer who tolerate treatment well.

How patients experience endocrine therapy for breast cancer: an online survey of side effects, adherence, and medical team support

“…Despite the known efficacy of ET, up to 30% of patients with invasive HR+ breast cancer who are prescribed ET never initiate therapy [9]. In addition, 18% to 73% of patients who initiate ET do not complete the prescribed course of treatment [2,4,6,[9][10][11][12][13][14][15][16][17][18][19]. Early discontinuation of therapy is associated with increased recurrence and breast cancer-specific mortality rates, as well as higher medical costs [2,9,11,[18][19][20][21].…”

Connecting the Missing Dots: ncRNAs as Critical Regulators of Therapeutic Susceptibility in Breast Cancer

“…However, 20-30% BC patients fail to respond to therapy, due to the intrinsic or extrinsic drug resistance, which often leads to metastatic disease and death [36]. The combined use of tamoxifen with AIs was shown to improve the therapeutic benefits in postmenopausal women, both in early and advanced stages [37]. However, the development of resistance to these first-line therapies remains a significant hurdle in BC Here, we present a timely and detailed review of the latest research findings on the mechanisms that govern drug resistance acquisition in BC, focusing mainly on the regulatory roles of the aforementioned ncRNAs in these processes.…”

Breast Cancer Typing Using Rt-PCR Assay

“…Наряду с хирургическим и лучевым методами одним из основных способов лечения данной категории пациентов остается адъювантная системная терапия, выбор которой на данный момент, согласно отечественным и международным рекомендациям, определяется молекулярно-генетическими подтипами опухоли, к которым относятся люминальный тип А, люминальный тип В (HER2-отрицательный), люминальный тип В (HER2-положительный), HER2-положительный и трижды негативные опухоли [2,3]. По современным представлениям, для этой цели с помощью стандартного иммуногистохимического (ИГХ) метода оцениваются рецепторный статус (рецепторы эстрогенов и прогестерона, рецептор эпидермального фактора роста HER2-neu), а также маркер клеточной пролиферации Ki67, определяемые иммуногистохимическим исследованием ткани основного опухолевого узла и пораженных лимфатических узлов [4][5][6].…”