Abstract

HER2, a human epidermal growth factor, being activated by amplification, is a negative prognostic factor in breast cancer. HER2 is the target of anti-HER2 antibodies (Trastuzumab, Pertuzumab…). For more than 10 years, breast cancers have been classified into HER2 positive and HER2 negative. However, the advent of new cytotoxic drugs combined with anti-HER2 antibodies, such as TDM1 or trastuzumab déruxtécan, have shown very promising therapeutic activity in patients with low HER2 expression breast cancer. These new therapeutic perspectives encourage a better identification of low HER2 tumours in order to identify patients who could benefit from them. Thus, the classification of breast tumours evolves to individualize HER2-negative tumours (score 0), HER2-positive tumours (score 3+ and 2+ amplified) and HER2-low tumours (scores 1+ and 2+ not-amplified). HER2-low tumours are common and represent more than half of all breast cancers. To identify these HER2-low tumours, pathology laboratories should not change their usual technique calibrated according to ASCO/CAP and GEFPICS recommendations. Until more clinical data about response to these new treatment strategies are available, GEFPICS does not require pathologists to identify this HER2-low category. Nevertheless, this designation will allow clinicians to identify patients whose tumours fall into this category in the very short term and offer them new treatment options.

• Authors: Élise Deluche, Anne Vincent-Salomon
• Journal: Bulletin du cancer (Bull Cancer) Vol. 108 Issue 11S Pg. 11S1-11S7 (Dec 2021) ISSN: 1769-6917 [Electronic] France
• Vernacular Title: « HER2-faible », un nouveau concept dans la prise en charge des cancers du sein: HER2-low breast cancer: a new concept in breast cancer treatment strategy.
• PMID: 34969511 (Publication Type: Journal Article, Review)
• Copyright: Copyright © 2021 Société FranÇaise du Cancer. Publié par Elsevier Masson SAS. Tous droits réservés.

Chemical References

• Antibodies, Monoclonal, Humanized
• Antineoplastic Agents, Immunological
• Immunoconjugates
• trastuzumab deruxtecan
• ERBB2 protein, human
• Receptor, ErbB-2
• pertuzumab
• Trastuzumab
• trastuzumab duocarmazine
• Camptothecin

Topics

• Antibodies, Monoclonal, Humanized (therapeutic use)
• Antineoplastic Agents, Immunological (therapeutic use)
• Breast Neoplasms (chemistry, classification, drug therapy, pathology)
• Camptothecin (analogs & derivatives, therapeutic use)
• Female
• Gene Amplification
• Genes, erbB-2
• Humans
• Immunoconjugates (therapeutic use)
• Neoplasm Recurrence, Local (chemistry)
• Practice Guidelines as Topic
• Receptor, ErbB-2 (analysis, antagonists & inhibitors)
• Trastuzumab (therapeutic use)