Comparison of serum HER-2/neu between trastuzumab-based regimen and anthyracycline-based regimen during neoadjuvant chemotherapy in advanced primary breast cancer

Abstract

e11582 Background: Serum Her-2/neu has been known as molecular surrogating marker of predicting treatment response in Her-2 positive breast cancer. We compare the change of serum Her-2/neu during neoadjuvant chemotherapy between trastuzumab(H) and anthyracyline(A) based treatment. Methods: All breast cancers were tested by immunohistochemical stain and FISH for Her-2/neu before treatment. Serum Her-2/neu was twice measured by Chemiluminescence immunoassay(ADVIA centaurTMsystem) before neoadjuvant chemotherapy and before operation. The cutoff value was 10.2 mg/ml according to previous study. Pathologic complete response (pCR) was considered as no residual tumor or remnant ductal carcinoma in situ, partial response (PR) was less than 50% decrease in maximal diameter in pathologic tumor size. Results: Serum Her-2/neu of trastuzumab group was more decreased than of anthyracyline group (H; 12.9 ± 14.5 ng/mL vs. A; 2.2 ± 1.2 ng/mL, p=0.024). In trastuzumab group, pCR was relatively correlated with decrease of serum Her-2/neu (PR: 0.8 ± 0.84 ng/ml vs. pCR: 21.1 ± 13.2 ng/ml, p=0.08). Conclusions: A decrease in serum Her-2/neu levels during treatment was associated with pathologic response in patients receiving neoadjuvant chemotherapy, particularly, trastuzumab-based regimen. Serum Her-2/neu levels may serve to monitoring neoadjuvant therapy in Her-2/neu positive breast cancer. No significant financial relationships to disclose.