The survival benefit of adjuvant trastuzumab with or without chemotherapy in the management of small (T1mic, T1a, T1b, T1c), node negative HER2+ breast cancer

• Published in: NPJ breast cancer Vol. 10; no. 1; pp. 49 - 8
• Main Authors: Johnson, Kai C. C., Ni, Ai, Quiroga, Dionisia, Pariser, Ashley C., Sudheendra, Preeti K., Williams, Nicole O., Sardesai, Sagar D., Cherian, Mathew, Stover, Daniel G., Gatti-Mays, Margaret, Ramaswamy, Bhuvaneswari, Lustberg, Maryam, Jhawar, Sachin, Skoracki, Roman, Wesolowski, Robert
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 19.06.2024; Nature Publishing Group UK; Nature Portfolio
• Subjects: Breast cancer; Cancer therapies; Chemotherapy; Clinical outcomes; Combination therapy; Multivariate analysis; Patients; Tumors
• ISSN: 2374-4677; 2374-4677
• DOI: 10.1038/s41523-024-00652-4

Abstract There is limited data regarding the added benefit of adjuvant systemic therapy in the management of small, node-negative, HER2+ breast cancer. In a multi-institutional retrospective analysis using the American Society of Clinical Oncology CancerLinQ database, we compared survival outcomes among T1a-c N0 HER2+ patients diagnosed between 2010 to 2021 who received locoregional therapy alone or in combination with adjuvant trastuzumab (+/− chemotherapy). Primary outcomes were invasive disease-free survival (iDFS) and overall survival (OS). Of the 1,184 patients, 436 received locoregional therapy alone. We found a statistically significant improvement in iDFS (HR 0.73, P = 0.003) and OS (HR 0.63, P = 0.023) on univariate analysis with adjuvant trastuzumab with or without chemotherapy which remained statistically significant on multivariate analysis. Three-arm univariate analysis found that iDFS was significantly improved with trastuzumab monotherapy ( P = 0.003) and combination therapy ( P = 0.027) compared to observation. Subgroup data suggests that T1b/c tumors derive the greatest benefit.