Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial

Maria Vittoria Dieci, Giancarlo Bisagni, Alba A. Brandes, Antonio Frassoldati, Luigi Cavanna, Francesco Giotta, Michele Aieta, Vittorio Gebbia, Antonino Musolino, Ornella Garrone, Michela Donadio, Anita Rimanti, Alessandra Beano, Claudio Zamagni, Hector Soto Parra, Federico Piacentini, Saverio Danese, Antonella Ferro, Katia Cagossi, Samanta SartiAnna Rita Gambaro, Sante Romito, Viviana Bazan, Laura Amaducci, Gabriella Moretti, Maria Pia Foschini, Sara Balduzzi, Roberto Vicini, Roberto D'Amico, Gaia Griguolo, Valentina Guarneri, Pier Franco Conte

Research output: Contribution to journalArticle

Abstract

Background: The 8th edition of the American Joint Committee on Cancer (AJCC) staging has introduced prognostic stage based on anatomic stage combined with biologic factors. We aimed to validate the prognostic stage in HER2-positive breast cancer patients enrolled in the ShortHER trial. Methods: The ShortHER trial randomized 1253 HER2-positive patients to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. Patients were classified according to the anatomic and the prognostic stage. Distant disease-free survival (DDFS) was calculated from randomization to distant relapse or death. Results: A total of 1244 patients were included. Compared to anatomic stage, the prognostic stage downstaged 41.6% (n = 517) of patients to a more favorable stage category. Five-year DDFS based on anatomic stage was as follows: IA 96.6%, IB 94.1%, IIA 92.4%, IIB 87.3%, IIIA 81.3%, IIIC 70.5% (P < 0.001). Five-year DDFS according to prognostic stage was as follows: IA 95.7%, IB 91.4%, IIA 86.9%, IIB 85.0%, IIIA 77.6%, IIIC 67.7% (P < 0.001). The C index was similar (0.69209 and 0.69249, P = 0.975). Within anatomic stage I, the outcome was similar for patients treated with 9 weeks or 1 year trastuzumab (5-year DDFS 96.2% and 96.6%, P = 0.856). Within prognostic stage I, the outcome was numerically worse for patients treated with 9 weeks trastuzumab (5-year DDFS 93.7% and 96.3%, P = 0.080). Conclusions: The prognostic stage downstaged 41.6% of patients, while maintaining a similar prognostic performance as the anatomic stage. The prognostic stage is valuable in counseling patients and may serve as reference for a clinical trial design. Our data do not support prognostic stage as guidance to de-escalate treatment. Trial registration: EUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Original languageEnglish
Article number207
JournalBMC Medicine
Volume17
Issue number1
DOIs
Publication statusPublished - Nov 21 2019

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Keywords

  • 8th AJCC
  • Breast cancer
  • HER2-positive
  • Prognostic stage
  • Trastuzumab

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Dieci, M. V., Bisagni, G., Brandes, A. A., Frassoldati, A., Cavanna, L., Giotta, F., Aieta, M., Gebbia, V., Musolino, A., Garrone, O., Donadio, M., Rimanti, A., Beano, A., Zamagni, C., Soto Parra, H., Piacentini, F., Danese, S., Ferro, A., Cagossi, K., ... Conte, P. F. (2019). Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial. BMC Medicine, 17(1), [207]. https://doi.org/10.1186/s12916-019-1445-z