HER2/Neu Distribution in Female Breast Cancer in Libya: Correlation with Clinicopathological Features and Survival

Background: HER2 protein over-expression is of great importance to guide hormone therapy. The present study aimed to determine the HER2 status of Libyan women with breast cancer and evaluate the correlation of HER2 expression with some clinicopathological features as well as overall survival (OS). Patients and methods: Data on 245 women with a diagnosis of breast cancer who were registered at the Misurata Cancer Center (MCC) in Libya from January 2004 to December 2012 were retrospectively studied. Patients’ demographic and clinicopathological data were collected and immunohistochemistry testing for HER2 was performed on the formalin fixed paraffin-embedded blocks of breast tissue of these patients. Results: The mean age of women at diagnosis was 46.7 ± 12.4 years [range: 25-86 years] and the majority of the patients were post-menopausal women (57.1%). The majority of breast cancers were invasive ductal carcinoma (82.4%) of grade 2-3 (89%), stage 2-3 (81.6%) and lymph node involvement (65.3%). The tumors were large with an average size of 4.47 ± 2.8 cm. In total, 57.1% of the patients had tumors with negative HER2 expression, whereas 13.1% had HER2 overexpression. HER2 positivity was correlated with histological grade (p = 0.05), but not with family history (p = 0.9), menopausal status (p = 0.2), histological type (p = 0.5), tumor size (p = 0.4), clinical stage (p = 0.9), lymph node status (p = 0.8), metastatic location (p = 0.71), recurrence (p = 0.4), or status at last follow-up (p = 0.09). OS was significantly shorter in patients with higher tumor stage (p < 0.0001), larger tumor size (p = 0.0001) and higher grade (p = 0.001), as well as those with systemic metastasis (p < 0.0001). Longer survival rate seemed to be more associated with negative HER2 expression, despite data being not statistically significant. Conclusions: These results support the systematic use of HER2 expression as a prognostic and predictive marker to identify patients who may benefit from chemotherapy or targeted therapy that will improve their survival.