Mutational analysis of BRCA1/2 gene and pathologic characteristics from Kazakh population with sporadic breast cancer in northwestern China

Abstract

ABSTRACT. Mutations in the BRCA1/2 genes are associated with an increased risk of breast cancer, but no large-scale research have examined the BRCA1/2 mutations in Chinese Kazakh women. We evaluated the frequency and distributions of BRCA1 and BRCA2 gene mutations in Kazakh sporadic breast cancer patients and healthy women in China. The association between the clinical-pathologic features of Kazakh breast cancer patients and BRCA1/2 mutations were also investigated. Two unclassified variants (T539M and T1915M) and 16 polymorphisms were detected in this study, 4 of which (G356A, His743, Asn991Asp, Val1269) were detected more frequently in breast cancer patients than in healthy controls. We observed a higher prevalence of BRCA1/2 common sequence alterations and a large number of Kazakh women carrying multiple coexisting BRCA1/2 mutations. The prevalence of BRCA1 mutations was similar to that of BRCA2 mutations. Although no significant differences were observed, BRCA1/2 carriers were generally younger at diagnosis (2015) of wild-type breast cancer patients. BRCA1-associated Kazakh sporadic breast cancers present with high tumor grade, early stage, negative lymph node status, absence of estrogen receptor expression and progesteronepositive status. Estrogen receptor expression was the only predominant histological type in BRCA2 carriers. In this study, we determined the BRCA1 and BRCA2 gene mutation status and determined the association with clinical-pathologic characteristics in a Chinese Kazakh population. Larger population-based screening studies screening the entire coding region of BRCA1/2 are required to evaluate the breast cancer risk induced by the sequence alterations detected in this study.

The Characteristics Comparison of Breast Cancer Patients in Southern China and America: A Multicentre Study in China Versus SEER Database

“…Zhang G et al found that compared with the white, the expression of TP53 and AKT1 is higher in Chinese, which may be a potential factor affecting the incidence of BC [22]. Yang SY et al found that the morbidity of BC is different between China and other Asian populations, and the mutation frequency of BRCA2 was much higher than that of BRCA1, by comparison, BRCA1 mutations are more common than BRCA2 mutations in Caucasian populations [23]. Chen L et al researched the Asia and African Americans, discovering that there are more than 50% of BC cases in Asia were lumA subtype, and the basal-like subtype only accounts for 5%, however, in African-American populations, this subtype accounts for more than 30% [24].…”

The Comparison of Breast Cancer in Southern China and America: a Multicentre Study in China Versus SEER Database

“…Yang SY et al found that the morbidity of BC is different between China and other Asian populations, and the mutation frequency of BRCA2 was much higher than that of BRCA1, by comparison, BRCA1 mutations are more common than BRCA2 mutations in Caucasian populations [23]. Chen L et al researched the Asia and African Americans, discovering that there are more than 50% of BC cases in Asia were lumA subtype, and the basal-like subtype only accounts for 5%, however, in African-American populations, this subtype accounts for more than 30% [24].…”