Clinical Drug Experience Knowledgebase

Breast cancer is a heterogeneous disease and can be classified into several distinctive subgroups. Triple-negative breast cancer(TNBC) is defined by lack of estrogen(ER), progesterone(PR) immunoreactivity and lack of human epidermal receptor-2(HER2) overexpression. TNBC comprises around 15% of all breast cancer and is characterized by its aggressive clinical behavior and insensitivity toward available targeted treatment strategies such as endocrine and anti-HER2 therapies.Although TNBC is sensitive to chemotherapy,early relapse with metastatic disease is common and the prognosis is poor. Development Of novel treatment strategies is,therefore,needed and the study of other potential targets in TNBC,like tyrosine kinase receptors,is a topic of interest.

Epidermal Growth Factor Receptor(EGFR) is a transmembrane receptor tyrosine kinase that encoded by cell erythroblastosis virus oncogene B1(C-erbB1) and belongs to the HER/Erythroblastosis virus oncogene B(ErbB) family. By several signal pathways,EGFR regulates cell proliferation, differentiation, apoptosis, invasion,and angiogenesis,and serves as a poor prognostic factor.EGFR is overexpressed in a variety of malignancies including TNBC.Gene expression profiling and immunohistochemical studies have indicated that 40 to 60% of TNBCs exhibit EGFR expression and gene amplification was found in 18% of this subgroup,but EGFR mutation was rare in TNBC.

By far,the role of gefitinib, an EGFR tyrosine kinase inhibitor(TKI),in the metastatic TNBC has not been identified. Most clinical trials about EGFR TKIs in the breast cancer have one or more limitations including:1) the study population had received heavily pretreatment; 2)the enrolled patients included several subgroups of breast cancer; 3)the expression of EGFR was not clear in the enrolled patients.

Here, the investigators launch a prospective clinical trial, and about 50 patients with triple-negative,EGFR positive metastatic breast cancer that have received at least second line therapy will be enrolled. these patients will be treated with gefitinib, the toxicity and effects of gefitinib will be recorded prospectively to evaluate the role of gefitinib in the metastatic TNBC.