Assessment of HER2NEU Gene Amplication by Flourescence in Situ Hybridization in Breast Carcinoma with Equivocal Findings on Immunostaining

Abstract

Objective: To determine the frequency of HER2/neu gene amplification by fluorescence in situ hybridization in Breast carcinoma patients with equivocal findings and to see its association with different clinicopathological features.

Study Design: Cross-sectional study.

Place and Duration of study: Medical Oncology Department, Jinnah Postgraduate Medical Center, Karachi, from Jan 2019 to Jan 2020.

Methodology: Total 166 females of age 22-72 years with diagnosis of invasive breast carcinoma which scored 2+ for HER2/neu by immunostaining were included in the study. Data regarding socio-demographics and clinicopathological features were noted for all the cases. Each patient was evaluated for estrogen and progesterone receptor status by immunostaining and score
of 0 to 2 was deemed as negative while score 3 to 8 was deemed as positive. Patients having equivocal HER2/neu on immunostaining was further tested for gene amplification by fluorescence in situ hybridization.

Results: The mean age of study participants was 46.98±11.22 years (Range: 22-72 years). Out of 166(56.5%) showed gene amplification by fluorescence in situ hybridization. Statistically significant association was found between stage of tumor and HER2/neu (p=0.036).

Conclusion: HER2/neu gene amplification by fluorescence in situ hybridization is detected in more than half of patients with equivocal findings on IHC and HER2/neu is strongly correlated with stage of tumor.