Background and Aim: Breast cancer is the most prevalent cancer in women. To date, regional differences in breast cancer risk factors have not been identified. The aim of our review was to gain a better understanding of the role of risk factors in women with breast cancer in Asia. Methods: We conducted a PubMed search on 15 March 2016, for journal articles published in English between 2011 and 2016, which reported data for human subjects in Asia with a diagnosis of breast cancer. Search terms included breast neoplasm, epidemiology, Asia, prevalence, incidence, risk and cost of illness. Studies of any design were included, except for review articles and meta-analyses, which were excluded to avoid duplication of data. No exclusions were made based on breast cancer treatment. We reported the results using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results: A total of 776 abstracts were retrieved. After screening against the eligibility criteria, 562 abstracts were excluded. The remaining 214 abstracts, which were published between 2013 and 2015, were included in this review. Results were summarized and reported under three categories: incidence, prevalence or outcomes for breast cancer in Asia; modifiable risk factors; and non-modifiable risk factors. We found that the increased risk of breast cancer among participants from Asia was associated with older age, family history of breast cancer, early menarche, late menopause, high body mass index, being obese or overweight, exposure to tobacco smoke, and high dietary intake of fats or fatty foods. In contrast, intake of dietary fruits, vegetables, and plant- and soy-based products was associated with a decreased breast cancer risk. While based on limited data, when compared to women from the United States, women from Asia had a decreased risk of breast cancer. Conclusions: This review of 214 abstracts of studies in Asia, published between 2013 and 2015, confirmed the relevance of known non-modifiable and modifiable risk factors for women with breast cancer.

Kang SY, et al. J Breast Cancer. 2019 Nov;23:e24. https://doi.org/10.4048/jbc.2020.23.e24

Kang SY, et al. J Breast Cancer. 2021 Apr;24(2):123-137. https://doi.org/10.4048/jbc.2021.24.e22

Epigallocatechin gallate (EGCG), a major constituent of green tea, has potential as a treatment for a variety of diseases, including cancer. EGCG induces apoptosis and inhibits tumorigenesis through multiple signaling pathways in breast cancer cells. β‑catenin signaling modulators could be useful in the prevention and therapy of breast cancer. However, the precise anticancer effect of EGCG through the β‑catenin signaling pathway in breast cancer is unclear. The present study investigated the association between β‑catenin expression and clinicopathological factors of breast cancer patients, and the effect of EGCG on β‑catenin expression in breast cancer cells. β‑catenin expression was analyzed according to the clinicopathological factors of 74 patients with breast cancer. All patients were females diagnosed with invasive ductal carcinoma. Western blot analysis revealed that β‑catenin was expressed at higher levels in breast cancer tissue than in normal tissue. β‑catenin expression was associated with lymph node metastasis (P=0.04), tumor‑node‑metastasis stage (P=0.03) and estrogen receptor status (P<0.01). EGCG decreased MDA‑MB‑231 cell viability and significantly downregulated the expression of β‑catenin, phosphorylated Akt and cyclin D1. Remarkably, additive effects of LY294002 and wortmannin, two phosphatidylinositol‑3 kinase inhibitors, were observed. The present results suggest that EGCG inhibits the growth of MDA‑MB‑231 cells through the inactivation of the β‑catenin signaling pathway. Based on these promising results, EGCG may be a potential treatment for triple negative breast cancer patients.

The Korean Breast Cancer Society (KBCS) has established a nationwide breast cancer database using an online registration program in 1996. The present study aimed to analyze the basic findings and trends of breast cancer in Korea in 2015 using the data provided by the Korea Central Cancer Registry and the KBCS. In 2015, a total of 22,550 patients were newly diagnosed with breast cancer, of which 3,331 were carcinoma in situ cases and 19,219 were invasive cancer cases. The incidence rate of breast cancer in Korea has steadily increased since the nationwide database was established, and the crude rate and age-standardized rate including that of carcinoma in situ, were 88.1 and 66.0 cases per 100,000 women, respectively. In terms of age, the incidence of breast cancer was the highest in the 40-49-year-old age group (7,889 patients, 35.0%). With regard to surgical procedure, breast-conserving surgery was frequently performed (62.3%). However, the rate of mastectomy has been gradually increasing since 2012, that is, from 32.3% in 2014 to 36.1% in 2015. The rate of early breast cancer has continued to increase, and that of stages III and IV breast cancer was only 9.1% at the time of diagnosis. However, the 5-year survival rate of patients with carcinoma in situ from 2011 to 2015 was 92.3%, which was 14.4% higher than that from 1993 to 1995 (77.9%). Analysis of data from the nationwide registry of breast cancer will not only help to understand the characteristics of breast cancer in individuals in Korea, but will also significantly contribute to the treatment and research of breast cancer. Therefore, a high quality database for breast cancer in Korea must be established by further initiating registration project and establishing an objective legal basis.

Nerve growth factor (NGF) is a neurotrophin and has been suggested to induce heme oxygenase-1 (HO1) expression. Although the role of HO1 in tumorigenesis remains controversial, recent evidence suggests NGF and HO1 as tumor-progressing factors. However, the correlative role of NGF and HO1 and their prognostic impact in breast carcinoma is unknown.