Expression of breast cancer type 1 and its relation with expression of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2/neu in breast carcinoma on trucut biopsy specimens

Expression of BRCA1 by immunohistochemistry and its association with ER, PR, Her2neu status in infiltrative ductal carcinoma of breast

BACKGROUND

Breast cancer is a heterogeneous disease, which differs in its clinical behaviors and responses to treatment and outcome. The prognosis of breast cancer depends on histopathological parameters and molecular subtypes. Among more than 300 genes, which are involved in the pathogenesis of breast cancer tumor suppressor gene such as BRCA1 is known to play a significant role in hereditary cancers. However, its role in sporadic cases of infiltrating ductal carcinoma is yet to be established.

AIMS AND OBJECTIVES

To evaluate the expression of BRCA1 in infiltrative ductal carcinoma and to analyze the association of BRCA1 with histopathological parameters and estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor2 (Her2) neu expression.

MATERIALS AND METHODS

This was a laboratory-based exploratory study in which 56 patients with infiltrative ductal carcinoma who underwent radical mastectomy from October 2019 to July 2021 were included. Patients with chemotherapy and radiotherapy, trucut biopsies, and incomplete patient details were excluded. Immunostaining for BRCA1 was performed. Individual clinicopathological parameters were compared with the BRCA1 mutation. Statistical analysis was done using SPSS 22. A P value of < 0.05 was considered statistically significant.

RESULTS

Among 56 cases of IDC, 18 cases (32.1%) showed BRCA1 mutation. BRCA1 mutation was associated with postmenopausal age, larger tumor size, lower tumor grade, and higher tumor staging. When we analyzed the biomarkers with BRCA1 mutation, it showed a negative association with ER, PR, and Her2 neu and a high Ki67 proliferation index. No family history of breast carcinoma was seen in 34/56 patients where history was available.

CONCLUSION

Our study showed BRCA1 mutation in 32.1% and associated with postmenopausal age group, larger tumor size, and higher staging and negative hormonal status of breast carcinoma.

Immunohistochemical Expression of BRCA1 Protein, ER, PR and Her2/neu in Breast Cancer: A Clinicopathological Study

Breast cancer is a heterogeneous hormone-dependent disease. Potential prognosis depends on the clinicopathological evaluation and assessment of other prognostic indicators. The detection of the oestrogen Receptor (ER), Progesterone Receptor (PR), Human epidermal growth factor receptor 2 (Her2/neu) and BRCA1 oncoprotein is pivotal for prognostic evaluation and to choose the appropriate post-surgical adjuvant therapy beside selecting the proper candidate for genetic counselling.

OBJECTIVES

To detect the immunoexpression of the BRCA1 oncoprotein in mammary invasive ducal carcinoma and its association with the prognostic markers (ER, PR and Her2/neu hormonal receptors) and other clinicopathological parameters to improve the patients' treatment plans.

METHODS

A cross-sectional study design including 83 paraffin blocks and histological slides collected from Al-Jumhoori Medical City Teaching Hospital Laboratory in Mosul and the Central Public Health Laboratory in Baghdad between the 1st of January 2010 to the 13th of March 2012 for patients diagnosed with primary invasive ductal breast carcinomas. Immunohistochemistry (IHC) using monoclonal antibodies against ER, PR, Her2/neu receptors and BRCA1 protein was performed via the fully automated immunostaining instrument 'Ventana Benchmark'.

RESULTS

BRCA1 protein immunoexpression was detected in 20.5% of cases. It was significantly high with increasing tumour grade and stage. Although there was a trend of BRCA1 negativity toward negative ER, PR and Her2 receptors, no significant associations were observed with any of these parameters and the patients' age.

CONCLUSION

Altered BRCA1 expression is significantly associated with advanced tumour grade and stage. High number of cases with negative BRCA1 expression showed negative ER, PR and Her2/neu expression.