Expression of HER2/neu in primary and metastatic breast cancer.
The study was performed for answering the question whether metastatic breast cancer has the same overexpression of HER2/neu as primary breast tumor. We assumed that study on this subject could give a valuable information for proper interpretation of HER2/neu overexpression in breast cancer patients designated for therapy with Herceptin. Our study was performed on 71 breast cancer patients qualified for clinical trial with Herceptin therapy. All patients selected for this trial have had surgery and two episodes of unsuccessful adjuvant therapy. Tissue samples were routinely fixed in 4% formalin and embedded in paraffin. Immunohistochemical assays were performed on 5 microns slides using DAKO HercepTest and semi-quantitative methods to determine HER2 protein overexpression were used. All study cases were subdivided into two groups. First group--49 cases in which expression of HER2 was examined in tissue from primary breast tumors, and second group--22 cases in which expression of HER2 was examined in tissue from metastatic lesions. In the whole study group (71 cases) overexpression was confirmed in 29 (40.8%) cases. In the group of primary breast tumors overexpression of HER2 was present in 20 (40.8%) of cases. In the group of metastatic breast tumors overexpression of HER2 was present in 9 (40.9%) of cases. The result suggests that overexpression which appears in primary breast carcinoma is also preserved in metastases. Direct prove of such a conclusion, would be a study on HER2/neu expression estimated in primary and metastases in the same patients. It requires a proper quantity and quality of material. Our results indicate that there is no difference between the estimation of HER2/neu overexpression in primary and metastatic breast cancer in patients with disseminated disease after double failure of chemotherapy. Evaluation of overexpression of HER2/neu in cases of planned Herceptin therapy can be done both in material from primary and from metastatic tumor.
Tuziak
T
T
Department of Pathology, Center of Oncology, Warszawa.
Olszewski
W P
WP
Olszewski
W
W
Pieńkowski
T
T
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism*; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*
D018719:Erb-b2 Receptor Tyrosine Kinases