Keywords
adjuvant endocrine therapy
abemaciclib
luminal breast cancer
early breast cancer
How to Cite
Abstract
Introduction. Although the prognosis for luminal HER2-negative breast cancer (HR+/HER2-BC) is significantly better than for other subtypes, patients with risk factors for progression, such as lymph node involvement, high Ki-67 and G, have a significant risk of relapse and require more intensive treatment. The monarchE study demonstrated that adding abemaciclib to standard endocrine therapy reduces the risk of disease progression and distant metastases by 32–33%. This is supported by improvements in five-year survival without invasive disease (IDFS) and without distant metastases (DRFS).
Aim. To study the use of abemaciclib in the adjuvant therapy of early high-risk luminal HR+/HER2- BC in real-life clinical practice in Moscow.
Materials and Methods. A prospective observational study was conducted, which included 163 patients with high-risk HR+/HER2- BC. By the time the data was analysed in December 2024, 28 patients had completed the abemaciclib therapy stage. The median follow-up period was 21.0 months (range 5.5-46.1). While the characteristics of the included patients are comparable to those in the monarchE study, it should be noted that a significantly higher proportion of patients received neoadjuvant chemotherapy (61.9% vs. 37.0%), and a higher percentage of patients had at least four affected lymph nodes (84.7% vs. 59.8%). IDFS and DRFS were assessed.
Results. IDFS events were reported in seven patients (4.3 %), of whom three had locoregional recurrences and three had distant metastases and one had metachronous cancer. The 6-month IDFS rate was 99.4%, the 12-month — 97.1%, and the 18-month — 95.8%, which is comparable to the monarchE data. The main adverse events were neutropenia (13.8%) and diarrhea (10.6%), but these were manageable in most cases.
Conclusion. Thus, the combination of abemaciclib and endocrine therapy is an effective adjuvant treatment strategy for high-risk HR+/HER2- BC, reducing the likelihood of systemic relapse. The drug's favorable safety profile makes it suitable for clinical use.
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Copyright (c) 2025 Людмила Григорьевна Жукова, Катерина Сергеевна Гречухина, Дарья Александровна Филоненко, Маргарита Витальевна Сухова, Дмитрий Владимирович Попов, Мария Алексеевна Иванюк, Ирина Ивановна Андреяшкина, Анастасия Сергеевна Данилова, Даниил Львович Строяковский, Татьяна Галяутдиновна Антонова, Илья Анатольевич Покатаев, Владимир Игоревич Евдокимов, Михаил Юрьевич Федянин, Николай Юрьевич Соколов, Игорь Евгеньевич Хатьков