The Significance of Topoisomerase II Alpha in Invasive Breast Carcinoma

Background Topoisomerase II alpha (Top 2 A) protein has been shown to be a proliferation marker associated with tumour grade. The current study evaluated the prognostic impact of Top 2 A protein on luminal breast cancer and its utility as an independent prognostic marker. Immunohistochemical expression of Top 2 A in breast cancer and its correlation with the tumour type, size, lymph node metastases, grade and ER/PR positivity. Methodology Ethics committee approval was taken and 65 cases of Invasive breast carcinoma presenting to the Department of Pathology at a tertiary care centre in South India were studied. Patient details including age, tumour type, tumour size, tumour grading, estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (HER2/neu) status and pathologic stage was studied. Immunohistochemistry (IHC) work-up for Top 2 A expression was done and evaluated. Results Of the 65 histological sections of breast cancers, 29/65 showed nuclear positivity for Top 2 A. Node positive tumours 17/65 stained positive for Top 2 A. Stage I tumours 2/65, stage II tumours 12/65 and stage III 14/65 stained positive for Top 2 A. Among the HER2/neu-positive tumours, 22/65 stained for Top 2 A and among ER/PR-positive 9/65 cases were positive for Top 2 A. Triple-negative tumours 5/65 stained for Top 2 A. Conclusion Higher Top 2 A expression was seen in higher stage tumours. HER2/neu-positive tumours significantly showed a correlation with Top 2 A positivity. Therefore, Top 2 A expression can be considered an individual prognostic factor in breast carcinoma.