Hereditary Breast Cancer in Korea: A Review of the Literature / 한국유방암학회지

ABSTRACT

Hereditary breast carcinomas associated with BRCA1/2 mutations have unique clinicopathological and epidemiological characteristics. The objective of this study is to outline the prevalence, founder effect and clinicopathological characteristics of BRCA1/2 mutations for hereditary breast cancers from an analysis of reports recently published regarding Korean subjects. The prevalence of BRCA1 and/or BRCA2 mutations is 2.5-3.1% for sporadic breast cancers, 19.4-42.9% for familiar breast cancer patients with two or more affected first- and second- degree relatives with breast or ovarian cancers and 9.6-18.3% for early breast cancers. Common mutations for the Korean subjects were 2552delC, 3476insA, 4184del4, 5589del8, and 5615del111insA for BRCA1; and 7708C>T for BRCA2. These mutations were not found in Ashkenazi Jewish or Icelandic subjects. The proportion of estrogen or progesterone receptor (ER/PR) or ER/PR/HER2 triple negative status, basal-like phenotype as detected by immunohistochemical staining, and undifferentiated histological grade in Korean BRCA mutation subjects were higher than in subjects lacking BRCA1/2 mutations. Our review found that previous studies describing BRCA mutations among Korean subjects were limited. Since the clinicopathological, phenotypic and epidemiological characteristics of the BRCA1/2 mutations among Korean subjects are different from those among subjects from the Americas and Europe, more studies of hereditary or familial breast cancer including BRCA mutations must be conducted. A largescale prospective study called Korean Hereditary Breast Cancer Study (KOHBRA) was started from May 2007, and future information provided by the KOHBRA study will make a substantial contribution to solving the basic questions in etiology, individual susceptibility and clinicopathological characteristics for hereditary breast cancer among Korean subjects.