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.