A comparison of baseline characteristics in patients with hormone receptor (HR)-positive, HER2-negative early breast cancer revealed that higher proportion of patients enrolled from Asia had risk factors for disease recurrence than those enrolled from non-Asian countries, researchers reported at the ESMO Asia Virtual Congress 2020, held from 20 to 22 November 2020.
In Hae Park of the Division of Internal Medicine, Centre for Breast Cancer, National Cancer Centre in Goyang, Republic of Korea presented the baseline data of patients from Asia and non-Asia enrolled in the open-label, phase III monarchE trial (NCT03155997), to characterise the demographics and disease characteristics of these populations and to identify patients with high risk features who may benefit from additional adjuvant treatment.
She explained that, even though the risk of recurrence for many patients with HR-positive, HER2-negative early breast cancer is relatively low since breast cancer is diagnosed at an early stage in approximately 90% of patients, the degree of risk may be increased by certain clinical and/or pathological features including the number of lymph nodes involved, tumour size, histologic grade, and the proliferation index. In addition, the clinical characteristics of patients with breast cancer are known to differ in Asian compared to Western countries.
The monarchE enrolled women and men with early breast cancer and ≥4 positive nodes, or 1-3 nodes plus either tumour size ≥5 cm, histologic grade 3, or central Ki-67 ≥20%. Patients with HR-positive, HER2-negative, node-positive, high risk early breast cancer were randomised by an interactive web response system and stratified by prior treatment, menopausal status, and region (North America/Europe versus Asia versus Other). Following randomisation patients received standard of care endocrine therapy with or without abemaciclib at 150 mg twice daily for up to two years.
Baseline characteristics identified more patients enrolled from Asia with high risk features indicating additional adjuvant therapy may benefit these patients
The study enrolled 1155 patients from Asia from July 2017 to August 2019, including 377 from Japan, 357 from China, 245 from Korea, 124 from Taiwan, 32 from Singapore, and 20 patients from Hong Kong. The study also enrolled 4482 patients from non-Asia (abemaciclib/endocrine therapy arm, n = 2235; endocrine therapy arm, n=2247).
Comparison of patients from Asia and those not from Asia revealed the former tended to be younger, more commonly premenopausal, and had a higher incidence of ≥4 positive lymph nodes.
Specifically, patients from Asia receiving abemaciclib plus endocrine therapy versus those on endocrine therapy had median ages of 48 (range, 23-87) versus 48 (range, 23-84), 58.6% versus 58.4% had premenopausal status, 34.7% versus 34.5% had 1-3 positive nodes, and 65.1% versus 65.3% had ≥4 positive lymph nodes, respectively.
In contrast, patients in the respective treatment groups from non-Asia had median ages of 52 (range, 25-89) versus 52 (range, 22-86), 39.6% versus 39.7% had premenopausal status, 41.2% versus 41.9% had 1-3 positive nodes, and 58.5% versus 57.8% had ≥4 positive lymph nodes.
Across all 4 subsets the majority (99.8%, 99.7%, 99.1% and 99.4%, respectively) of patients were female.
Conclusions
The authors stated to their knowledge, these are the first reported baseline characteristics in patients from Asia with high risk early breast cancer in a study investigating a CDK4/6 inhibitor as adjuvant therapy.
They underscored that these characteristics suggest that patients from Asia may have a higher risk of recurrence than patients from non-Asia and would benefit from additional adjuvant treatment.
Funding was reported from Eli Lilly and Company.
Reference
LBA1 – Jiang Z, Nakayama T, Nakamura S, et al. Baseline characteristics of patients from Asia enrolled in monarchE, evaluating abemaciclib in high risk early breast cancer. ESMO Asia Virtual Congress 2020 (20-22 November).