npj Breast Cancer (Jun 2024)

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

  • Kai C. C. Johnson,
  • Ai Ni,
  • Dionisia Quiroga,
  • Ashley C. Pariser,
  • Preeti K. Sudheendra,
  • Nicole O. Williams,
  • Sagar D. Sardesai,
  • Mathew Cherian,
  • Daniel G. Stover,
  • Margaret Gatti-Mays,
  • Bhuvaneswari Ramaswamy,
  • Maryam Lustberg,
  • Sachin Jhawar,
  • Roman Skoracki,
  • Robert Wesolowski

DOI
https://doi.org/10.1038/s41523-024-00652-4
Journal volume & issue
Vol. 10, no. 1
pp. 1 – 8

Abstract

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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.