Survival outcomes of young-age female patients with early breast cancer: an international multicenter cohort study

J Kim; J Kim; K H Seo; K-H Lee; Y H Park; C-H Lin; Y-S Lu; T Ueno; Y-S Yap; F-Y Wong; V K M Tan; G-H Lim; S-M Tan; W Yeo; Q Liu; R Leung; Y Naito; H Li; H-B Lee; W Han; S-A Im; Asian Breast Cancer Cooperative Group

doi:10.1016/j.esmoop.2024.103732

Survival outcomes of young-age female patients with early breast cancer: an international multicenter cohort study

ESMO Open. 2024 Oct 15;9(11):103732. doi: 10.1016/j.esmoop.2024.103732. Online ahead of print.

Authors

J Kim¹, J Kim², K H Seo², K-H Lee³, Y H Park⁴, C-H Lin⁵, Y-S Lu⁶, T Ueno⁷, Y-S Yap⁸, F-Y Wong⁹, V K M Tan¹⁰, G-H Lim¹¹, S-M Tan¹², W Yeo¹³, Q Liu¹⁴, R Leung¹⁵, Y Naito¹⁶, H Li¹⁷, H-B Lee¹⁸, W Han¹⁸, S-A Im¹⁹; Asian Breast Cancer Cooperative Group

Affiliations

¹ Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul.
² Medical Research Collaborating Center, Seoul National University Hospital, Seoul.
³ Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul; Cancer Research Institute, Seoul National University, Seoul. Electronic address: kyunghunlee@snu.ac.kr.
⁴ Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul; Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
⁵ Department of Medical Oncology, National Taiwan University Hospital, Cancer Center Branch, Taipei.
⁶ Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan.
⁷ Breast Surgical Oncology, Breast Oncology Center, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
⁸ Division of Medical Oncology, National Cancer Centre Singapore, Singapore; Duke-NUS Medical School, Singapore.
⁹ Duke-NUS Medical School, Singapore; Division of Radiation Oncology, National Cancer Centre Singapore, Singapore.
¹⁰ Duke-NUS Medical School, Singapore; SingHealth Duke-NUS Breast Centre, Singapore; Division of Surgery and Surgical Oncology, National Cancer Centre Singapore, Singapore; Department of Breast Surgery, Singapore General Hospital, Singapore.
¹¹ SingHealth Duke-NUS Breast Centre, Singapore; Breast Department, KK Women's and Children's Hospital, Singapore.
¹² SingHealth Duke-NUS Breast Centre, Singapore; Division of Breast Surgery, Department of General Surgery, Changi General Hospital, Singapore, Singapore.
¹³ Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Sha Tin, Hong Kong.
¹⁴ Breast Tumor Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou.
¹⁵ The University of Hong Kong, Hong Kong, China.
¹⁶ Department of General Internal Medicine, National Cancer Center Hospital East, Kashiwa, Japan.
¹⁷ Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing, China.
¹⁸ Cancer Research Institute, Seoul National University, Seoul; Department of Surgery, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
¹⁹ Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul; Cancer Research Institute, Seoul National University, Seoul. Electronic address: moisa@snu.ac.kr.

Abstract

Background: The incidence of breast cancer among young Asian women is increasing, yet they remain underrepresented in global data. We analyzed the epidemiology and outcomes of Asian patients with breast cancer <40 years old across different subtypes to identify their clinical unmet needs.

Patients and methods: Female patients aged ≥20 years diagnosed with early breast cancer were analyzed from the prospective cohort of the Asian Breast Cancer Cooperative Group (ABCCG). For comparison, data from the Surveillance, Epidemiology, and End Results Program (SEER) cancer registry were used. Patients were categorized into three age groups: young (<40 years), alleged premenopausal mid-age (40-49 years), and alleged postmenopausal (aged ≥50 years). Multivariable Cox proportional hazards models for survival were adjusted for subtypes, histologic grade, T stage, nodal status, and study centers.

Results: A total of 45 021 patients with breast cancer from Asian study centers, 496 332 SEER-White patients, and 18 279 SEER-Asian patients were included in the analysis. The median age at diagnosis was younger in the Asian cohort (51 years) compared with SEER-Whites (62 years) and SEER-Asians (58 years; P < 0.0001). In the young-age group, hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer was more prevalent among Asians and SEER-Asians compared with SEER-Whites (61.2% and 59.8% versus 54.7%). In the Asian population, young patients with HR+/HER2- breast cancer exhibited significantly inferior overall survival than the mid-age group (6-year overall survival 94.4% versus 96.6%; mid-age to young-age group hazard ratio 0.62; P < 0.001). Similarly, young patients in SEER-Whites showed an earlier decline in survival compared with the mid-age group (89.1% versus 94.0%; P < 0.001).

Conclusion: ABCCG-Asian patients with breast cancer <40 years old with HR+/HER2- subtypes were more likely to have worse survival outcomes than their mid-age counterparts. Our study highlights the poorer prognosis of young patients and underscores the need for a tailored therapeutic approach, such as ovarian function suppression, particularly considering ethnic factors.

Keywords: Asian; HR+/HER2− breast cancer; prevalence; survival; young.