PLoS ONE (Jan 2015)

The Promher Study: An Observational Italian Study on Adjuvant Therapy for HER2-Positive, pT1a-b pN0 Breast Cancer.

  • Stefania Gori,
  • Alessandro Inno,
  • Elena Fiorio,
  • Jennifer Foglietta,
  • Antonella Ferro,
  • Marcella Gulisano,
  • Graziella Pinotti,
  • Marta Gubiotti,
  • Maria Giovanna Cavazzini,
  • Monica Turazza,
  • Simona Duranti,
  • Valeria De Simone,
  • Laura Iezzi,
  • Giancarlo Bisagni,
  • Simon Spazzapan,
  • Luigi Cavanna,
  • Chiara Saggia,
  • Emilio Bria,
  • Elisabetta Cretella,
  • Patrizia Vici,
  • Daniele Santini,
  • Alessandra Fabi,
  • Ornella Garrone,
  • Antonio Frassoldati,
  • Laura Amaducci,
  • Silvana Saracchini,
  • Lucia Evangelisti,
  • Sandro Barni,
  • Teresa Gamucci,
  • Lucia Mentuccia,
  • Lucio Laudadio,
  • Alessandra Zoboli,
  • Fabiana Marchetti,
  • Giuseppe Bogina,
  • Gianluigi Lunardi,
  • Luca Boni

DOI
https://doi.org/10.1371/journal.pone.0136731
Journal volume & issue
Vol. 10, no. 9
p. e0136731

Abstract

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The management of pT1a-b pN0 HER2-positive breast cancer is controversial and no data about the efficacy of trastuzumab in this setting are available from randomized clinical trials. The aims of this retrospective study were to assess how patients are managed in clinical practice in Italy, which clinical or biological characteristics influenced the choice of adjuvant systemic therapy and the outcome of patients.Data of consecutive patients who underwent surgery from January 2007 to December 2012 for HER2-positive, pT1a-b pN0 M0 breast cancer were retrospectively collected from 28 Italian centres. Analysis of contingency tables and multivariate generalized logit models were used to investigate the association between the baseline clinical and biological features and the treatment strategy adopted.Among 303 enrolled patients, 204 received adjuvant systemic therapy with trastuzumab, 65 adjuvant systemic therapy without trastuzumab and 34 did not receive adjuvant systemic therapy. At the multivariate analysis age, tumor size, proliferation index and hormone receptor status were significantly associated with the treatment choice. Five-year disease-free survival (DFS) probability was 95%, 94.3% and 69.6% for patients treated with adjuvant systemic therapy and trastuzumab, with adjuvant systemic therapy without trastuzumab and for patients who did not receive adjuvant systemic therapy, respectively (p<0.001).The majority of patients (66%) with pT1a-b pN0 HER2-positive breast cancer enrolled in this retrospective study received adjuvant systemic therapy with trastuzumab, whereas only 11% patients did not receive any adjuvant systemic therapy. It should be emphasized, however, that in the adjuvant systemic therapy without trastuzumab group 94% of tumors were hormone receptor positive and 89% of patients were treated with endocrine therapy only [corrected]. The 5-year DFS probability was significantly higher for patients receiving adjuvant systemic therapy with trastuzumab compared with patients not receiving adjuvant systemic therapy or receiving adjuvant systemic therapy without trastuzumab.