Abstract
Purpose: The prospective Neoadjuvant Breast Registry Symphony Trial compared the 80-gene molecular subtyping signature with clinical assessment by immunohistochemistry and/or fluorescence in situ hybridization in predicting pathologic complete response (pCR) and 5-year outcomes in patients with early-stage breast cancer.
Methods: Standard-of-care neoadjuvant chemotherapy combined with trastuzumab or trastuzumab plus pertuzumab was given to patients with human epidermal growth factor receptor 2 (HER2)-positive tumors (n = 295). pCR was the primary end point, with secondary end points of distant metastasis-free survival and overall survival at 5 years.
Results: Among clinically defined HER2-positive (cHER2) tumors, the 80-gene assay identified 29.5% (87 of 295) as Luminal-Type (cHER2/gLuminal), 14.9% (44 of 295) as Basal-Type (cHER2/gBasal), and 55.6% (164 of 295) as HER2-Type (cHER2/genomically classified as HER2 [gHER2]). Patients with cHER2/gHER2 tumors had a higher pCR rate (61.6%) compared with non-gHER2 tumors (26.7%; P < .001). Dual targeting for cHER2/gHER2 tumors yielded a higher pCR rate (75%) compared with those treated with single HER2-targeted therapy (54%; P = .006). For cHER2/gBasal tumors, the 42.9% pCR rate observed with dual targeting was not different from that with trastuzumab alone (46.4%; P = .830). Among those with cHER2/gBasal tumors, 5-year distant metastasis-free survival (68.6%; 95% CI, 49.1 to 81.9) was significantly worse than in patients with cHER2/gLuminal tumors (88.9%; 95% CI, 78.0 to 94.6) and cHER2/gHER2 tumors (87.4%; 95% CI, 80.2 to 92.2; P = .010), with similar corresponding overall survival differences.
Conclusion: The 80-gene assay identified meaningful genomic diversity in patients with cHER2 disease. Patients with cHER2/gHER2 tumors, who benefitted most from dual HER2-targeted therapy, accounted for approximately half of the cHER2 cohort. Genomically Luminal tumors had low pCR rates but good 5-year outcomes. cHER2/gBasal tumors derived no benefit from dual therapy and had significantly worse 5-year prognosis; these patients merit special consideration in future trials.
Publication Date
9-22-2022
Content Type
Article
PubMed ID:
Citation
Whitworth, P. W., Beitsch, P. D., Murray, M. K., Richards, P. D., Mislowsky, A., Dul, C. L., Pellicane, J. V., Baron, P. L., Rahman, R. L., Lee, L. A., Dupree, B. B., Kelemen, P. R., Ashikari, A. Y., Budway, R. J., Lopez-Penalver, C., Dooley, W., Wang, S., Dauer, P., Menicucci, A. R., Yoder, E. B., … Audeh, W. (2022). Genomic Classification of HER2-Positive Patients With 80-Gene and 70-Gene Signatures Identifies Diversity in Clinical Outcomes With HER2-Targeted Neoadjuvant Therapy. JCO precision oncology, 6, e2200197. https://doi.org/10.1200/PO.22.00197
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Open Access: Creative Commons Attribution Non-Commercial No Derivatives 4.0 License