Insights Into Breast Cancer in the East vs the West

Abstract

IMPORTANCEDuring the past few decades, the incidence of breast cancer (BC) has been increasing rapidly in East Asia, and BC is currently the most common cancer in several countries. The rising incidence is likely related to changing lifestyle and environmental factors in addition to the increase in early diagnosis with BC awareness and screening. The understanding and management of BC are generally based on research and data from the West. However, emerging differences in BC epidemiology and tumor and host biology in Asian populations may be clinically relevant.OBSERVATIONS A higher proportion of premenopausal BCs occur in Asia, although this factor is possibly an age-cohort effect. Although the relative frequencies of different immunohistochemical subtypes of BC may be similar between the East and West, the higher prevalence of luminal B subtypes with more frequent mutations in TP53 may be confounded by disparities in early detection. In addition, Asian BCs appear to harbor a more immune-active microenvironment than BCs in the West. The spectra of germline mutations in BC predisposition genes and single-nucleotide polymorphisms contributing to BC risk vary with ethnicity as well. Differences in tolerability of certain cytotoxic and targeted agents used in BC treatment may be associated with pharmacogenomic factors, whereas the lower body mass of the average woman in East Asia may contribute to higher toxicities from drugs administered at fixed doses. Phenotypic characteristics, such as lower breast volume, may influence the type of surgery performed in East Asian women. On the other hand, increased breast density may affect the sensitivity of mammography in detecting BCs, limiting the benefits of screening mammography. CONCLUSIONS AND RELEVANCEBreast cancer has become a major health problem in Asia. The inclusion of more women from Asia in clinical trials and epidemiologic and translational studies may help unravel the interethnic heterogeneity of BCs and elucidate the complex interplay between environmental and intrinsic factors in its pathogenesis. These insights may help to refine prevention, diagnosis, and management strategies for BC in the setting of ethnic diversity.

A Phase Ib Study of Alpelisib or Buparlisib Combined with Tamoxifen Plus Goserelin in Premenopausal Women with HR-Positive HER2-Negative Advanced Breast Cancer

“…In the United States, breast cancer predominantly affects women ages 60 years and above, whereas in East Asia, incidence peaks in women ages 40-75 years (2). Approximately 42% of women in the Asia-Pacific region and 47% in Southeastern Asia were younger than 50 years at the time of diagnosis, in contrast to 20% of women in Western countries (3,4).…”

Molecular characterization of breast cancer: a potential novel immune-related lncRNAs signature

“…Globally, breast cancer (BC) is the most frequently common carcinoma in women [ 1 , 2 ]. In light of the statistics of the American Cancer Society, approximately 279,100 new BC cases and 42,690 cancer deaths are estimated to occur in the United States in 2020 [ 3 ].…”

The Molecular Landscape of Asian Breast Cancers Reveals Clinically Relevant Population-Specific Differences

“…Triple negative breast cancer is more common in African American women and a recent genomic analysis of 194 tumours show an increased HR deficiency signature, pervasive TP53 mutations, and greater structural variations, indicating a more aggressive biology 17 . Breast cancer in Asians tend to occur at a younger age, with a higher proportion of pre-menopausal, oestrogen receptor (ER) negative and human epidermal growth factor receptor 2 (HER2) receptor positive disease (reviewed in Yap et al 2019 18 ). A recent genomic analysis of 187 early-onset Asian breast cancers show a higher prevalence of TP53 mutations and enrichment in immune signatures 19 , whereas analysis of 465 triple-negative Asian breast cancers demonstrated broad similarities in tumours of the same subtype arising in Asian and Caucasian women 9 .…”