Frequency of BRCA1 Mutations in B&H Breast and Ovarian Cancer Patients

Abstract

Incidence of breast cancer ranges from 27 per 100,000 in Middle Africa and Eastern Asia to 92 per 100,000 in Northern America. It is the fifth most common cause of death from cancer in women, with an estimated 522,000 deaths per year (6.4% of the total). Autosomal dominant inheritance of these cancers is characterized by transmission of cancer predisposition from generation to generation, with around 5-10% of all breast cancers being associated with inherited mutations in BRCA1, BRCA2 and other genes. Breast and ovarian cancers are strongly associated with BRCA1 and BRCA2 mutations. In this study, we genotyped BRCA1 gene for large genomic rearrangements in breast and ovarian cancer patients from Bosnia and Herzegovina, with aim to assess frequency of large BRCA1 mutations (exon deletions/duplications) in this group. We collected 59 breast cancer samples, as well as other data concerning patients’ histopathological parameters of tumor, like age at diagnosis, cancer type, TNM class, cancer grade, as well as estrogen, progesterone and Her2/neu expression. Following DNA extraction from breast cancer samples (tissue after biopsy), BRCA1 mutations were identified by Multiplex Ligase - Dependent Probe Amplification (MLPA) analysis. Biostatistical analyses were conducted using MedCalc v.9.2.0.0 software. In all statistical tests p<0.05 was considered significant. Mean age at diagnosis was 54±1.75 (range 17 – 80). BRCA1 genomic rearrangements were found in 22% of breast and ovarian cancer patients. Statistically significant associations and correlations were found between BRCA1 genomic rearrangements and cancer type, estrogen, progesterone and Her2/neu expression, but not cancer grade, size, invasiveness or patients’ age.

Keywords

• BRCA genes
• breast cancer
• MLPA
• genomic rearrangements