Soussan Irani - Dental Research Centre, Oral Pathology Department, Dental Faculty, Hamadan University of Medical Sciences, Hamadan, Iran
Mitra Rafizadeh - Pathology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background: Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide and has a poor prognosis. The breast cancer ۱ (BRCA۱) and breast cancer ۲ (BRCA۲) genes are the key tumor suppressor genes responding in the cases of DNA damage. They repair double-strand DNA breaks to maintain gene stability. Mutations in BRCA۱ and BRCA۲ lead to genetic instability and develop different cancers, mainly familial breast and ovarian cancers. This study aimed to investigate the expression profiles of BRCA۱ and BRCA۲ genes in OSCC through the use of immunohistochemistry (IHC) technique. Method: In this retrospective study, a total of ۶۰ samples (۲۰ samples of each grade) were collected from the archive of pathology department of Taleghani educational hospital, Tehran, Iran, from ۲۰۰۰-۲۰۱۷. IHC staining was performed for all tissue samples. Results: BRCA۱ immunoreactivity was positive in the cytoplasm and nuclear of ۵۶ and ۲۴ samples, respectively. None of the cancer cells showed nuclear BRCA۲ expression; however, BRCA۲ cytoplasmic staining existed in ۱۷ cases. Chi-square test showed statistically significant differences between BRCA۱ staining (P=۰.۰۰۱) and histological grade, and between BRCA۲ expression (P=۰.۰۰۱) and histological grade in the research groups. Conclusion: Altered subcellular localization of BRCA۱/۲ and immunostaining of the cancer cells at the invasive front may indicate the critical role of BRCA۱/۲ in the development of OSCC. Early detection of BRCA mutation carriers by IHC has a significant impact on successful treatment.

BRCA۱, BRCA۲, Immunohistochemistry, Mouth, Neoplasm