Overexpression of c-erbB2 and its Relationship with Chemotherapy in Breast Ccancer / 한국유방암학회지

ABSTRACT

Purpose c-erbB2 encodes 185 kDa oncoprotein tyrosine kinase activity and has homology to the epidermal growth factor. c-erbB2 proto-oncogene is found to be overexpressed in approximately 20 to 30 % of primary breast cancer and has been associated with poor prognosis and lower response to conventional chemotherapy. Materials and methods We performed a stedy on 40 infiltrating ductal breast cancer treated with primary surgery and adjuvant chemotherapy. We investigated c-erbB2 expression by immunohistochemistry in paraffin-embedded tissue using polyclonal antipeptide antibody (DAKO). We evaluated the relationships between its expression and the results after over 6 cycles of adjuvant chemotherapy including cyclophosphamide, methotrexate and 5-FU. Results The median age at diagnosis was 43 years and the median follow-up time was 47.3 months. Thirteen (32.1%) of 40 patients showed the c-erbB2 overexpression in the external domains of protein. There were no correlations among c-erbB2 amplification and other prognostic factors such as hormonal receptors, histologic grade and tumor size. Estrogen receptor and progesterone receptor showed tendency of inverse correlation with c-erbB2 overexpression but it was not statistically significant (p>0.05). c-erbB2 positive patients showed shorter disease free survival compared to c-erbB2 negative patients in univariate analysis (p0.05). Conclusion These findings suggest that overexpression of c-erbB2 may be a marker of poor response to adjuvant chemotherapy with CMF regimen and may be an indicator of more aggressive therapy.