Study of BRCA1 and BRCA2 Gene Mutations and Clinicopathological Criteria of Breast Cancer in Thi-Qar

Abstract

Breast cancer is the commonest type of malignancy in Iraq. For this reason we study risk factors that associated with this disease in  Thi Qar province patients.  Such as mutations of breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2), clinicopathological parameter ( age, family history and tumor site) . Eighty five blood samples were taken from patients who attended Al-Hussain teaching hospital and oncology unit in Al-Habboby hospital during the period (from August /2014 to April /2017) , fifty blood samples were collected from healthy women as a control. Blood samples were using in genetic study.  For histopathological analysis fifty tissue samples were collected from fifty patients with breast cancer who were undergoing surgical resection (mastectomy) to prepare paraffin embedded blocks which have been used for histopathological diagnosis. The present study results  revealed that a highest incidence of breast cancer occur in the age group between 40-49 years of age (41%),there is a significant difference among patients age groups (P ≤ 0.01). Family history of breast cancer indicates a strong association with risk of developing breast cancer. The present study showed that family history positive in 31 cases (36.47%), and  54 cases (63.52%) had negative family history of breast cancer. Also the results of present study showed that the 34 cases (41.5%) had first birth at age (20-29years), 18 cases (23.37%) had their first birth in age groups (15-19 years) and (30-39 years), and 7 cases (9.09%) had first birth at age (≥40 years).  Most of patients (50.5%) breast cancers were located in right breast and (38.8%) of cases breast cancers were located in left side. Histopathologically, carcinoma was divided into 44 cases (88%) were ductal carcinoma {from which 42 cases(84%) were invasive ductal carcinoma, and 2 cases (4%) were comedocarcinoma}, and 6 (12%) cases were invasive lobular carcinoma. Results revealed that 2 cases (4%) were stage I, 13 cases (26%) were stage II, 24 cases (48%) were stage III and 11 cases (22%) were stage IV, also our results showed that  2 cases (4%) were grade I, 23 cases (46%) were grade II, and 25 cases (50%) were grade III. The DNA was extracted from blood samples by using Accupower® genomic DNA extraction kit. The concentration and purity of all DNA samples have been measured by Nanodrop. Samples with a purity ranged from 1.7 to 1.9 have been enrolled in this study for the molecular detection of BRCA1/2 gene mutation in patients and control groups. In 85 cases of breast cancer, detection  of BRCA1/2 gene mutation  by multiplex PCR done for the serum revealed that;  (185 del AG) mutation in BRCA1 gene was detected in 6 patients (7.05%), and (5382 ins C) mutation in the same gene was detected in 2   patients (2.35%).  Regarding (6174 del T) mutation in BRCA2 gene was detected in 3 patients (3.52%). In the control patients gene mutations of any types didn’t detected.