Association of HER-2 Copy Number and HER-2/CEP-17 Ratio with Neoadjuvant Taxane-Containing Chemotherapy Sensitivity in Locally Advanced Breast Cancer

摘要

Purpose. Aneusomy 17 causes inconsistency in fluorescence in situ hybridization (FISH)-based human epidermal growth factor receptor (HER)-2 status assessment using different algorithms (copy number or the HER-2/centromere enumerator probe 17 [CEP-17] ratio). We investigated the effects of FISH-based HER-2 status assessment and aneusomy 17 on responsiveness to neoadjuvant chemotherapy (NAC). Patients and Methods. This prospective study recruited 152 patients with locally advanced breast cancer who underwent four-cycle weekly paclitaxel plus carboplatin without trastuzumab. Results. The pathologic complete remission (pCR) rate in the breast and axilla was 24.3% (95% confidence interval [CI], 17.7%a??32.0%). Although HER-2 status, assessed by either HER-2/CEP-17 ratioa??based FISH or copy numbera??based FISH, was a predictor of NAC sensitivity, ratioa??assessed HER-2 status had a poorer performance in determining patients' responsiveness to NAC (p = .029). Patients who were not HER-2 amplified when assessed using the HER-2/CEP-17 ratio but were HER-2 amplified when assessed using copy number (a??5%) were eventually proven to be responsive to NAC, with a pCR rate of 57% (95% CI, 18.4%a??90.1%). In contrast, patients who were HER-2 amplified when assessed by the ratio but not HER-2 amplified when assessed using copy number (a??3%) were completely irresponsive. Higher HER-2 copy numbers represented increasing chances of a pCR (adjusted odds ratio, 3.09; 95% CI, 1.35a??7.08), with an apparent genea??dose effect (p for trend .001). Conclusion. It is likely that HER-2 copy number but not the HER-2/CEP-17 ratio determines NAC sensitivity. Additional studies to validate our findings are warranted. Footnotes.