Abstract
BACKGROUND
The objective of this study was to determine whether HERβ2 overexpression is associated with improved response to neoadjuvant chemotherapy with 5βfluorouracil, doxorubicin, cyclophosphamide (FAC) in patients with breast carcinoma.
METHODS
Ninetyβseven patients with Stage IβIII breast carcinoma were included. HERβ2 expression was determined by routine clinical laboratory assessment, and tumors with 3 + immunohistochemistry staining intensity or gene amplification by fluorescent in situ hybridization were considered HERβ2 positive. Response was assessed by physical examination, imaging assessment, and pathologic assessment at the time of surgery.
RESULTS
The median patient age was 45 years. At baseline, 68% of patients had lymph node positive disease, 87% had β₯ T2 tumors, and 28% of patients had HERβ2 positive tumors. Eightyβfour percent of patients received four courses of FAC, 8% of patients received 3 courses of FAC, and the remaining 8% of patients received 5β6 courses of FAC. The clinical response rate (complete response [CR] and partial response [PR]) was 78%, the imaging response rate (CR and PR) was 64%, and 15% of patients had a good pathologic response, defined as a CR or minimal residual disease (tumor measuring < 1 cm in greatest dimension and negative lymph nodes). Concordance between the three methods of response assessment (clinical, pathologic, and imaging) was modest and was best between clinical assessment and imaging assessment (64% concordance). HERβ2 status did not correlate with pathologic or clinical response (assessed by physical examination or imaging), although a nonsignificant trend was noted toward better response in patients with breast tumors that overexpressed HERβ2.
CONCLUSIONS
The authors found no significant correlation between HERβ2 expression and clinical or pathologic response to neoadjuvant chemotherapy in patients with breast carcinoma. Cancer 2003;97:1758β65. Β© 2003 American Cancer Society.
DOI 10.1002/cncr.11245