Abstract:
Objective To compare triple negative and human epidermal growth factor receptor (HER2) overexpression breast cancer in terms of Topoisomerase (Topo) Ⅱα expression in relation to reasonable clinical prognosis and rational use of drugs to provide better theoretical basis.
Methods A total of 202 breast cancer patients were selected from Tianjin Medical University Cancer Hospital after surgery between January and July, 2004. Based on the expression of estrogen receptor, progesterone receptor, and HER2, 101 triple negative breast cancer cases and 101 HER2-overexpressing breast cancer cases were setected. Using immunohistochemical methods, Topo Ⅱα protein expression in the two types of breast cancer and its relation to prognosis were determined.
Results Topo Ⅱα protein expression was 51.9% in HER2 overexpression breast cancer and 48.9% in triple negative breast cancer; the difference was not significant (P > 0.05). Topo Ⅱα protein expression had no correlation with age, tumor size, clinical stage, axillary lymph node status, histological grade, pathological type, or other clinicopathological parameters (P > 0.05). The 5-year disease-free survival (DFS) rate was 81.0% in the Topo Ⅱα and HER2 co-expression subtype, and 60.5% in the Topo Ⅱα-negative HER2-positive group; the difference was statistically significant (P = 0.037). The 5-year overall survival rate was 92.1% in the Topo Ⅱα and HER2 protein co-expression subtype, and 76.3% in the Topo Ⅱα-negative HER2-positive group; the difference was statistically significant (P = 0.047). Multivariate Cox regression analysis showed that Topo IIct was a prognostic factor of HER2-overexpressing breast cancer. For triple negative breast cancer, the Topo Ⅱα-positive and -negative 5-year DFS rates were 69.7% and 82.4%(significantly different, P = 0.044), and the OS rates were 75.0% and 84.5% (not significantly different, P = 0.927).
Conclusion For HER2 overexpressing breast cancer, patients with Topo IIα-positive expression had poorer prognosis. Hence, close attention should be paid to the clinical prognosis of these patients.