Highlights from

BCC 2019

St. Gallen International Breast Cancer Conference

Vienna 20-23 March 2019

St. Gallen Consensus - Adjuvant Her2-targeted therapy

For patients with Her2-positive early breast cancer, the standard management includes adjuvant chemotherapy plus Her2-targeted therapy. At the St. Gallen Conference 2019, the panel zoomed in on specific subtypes of Her2-positive early breast cancer. A small majority of the panellists (55%) took the view that Her2-targeted therapy is not required for patients with Her2-positive, T1a, node-negative breast cancer, while 43% of the panellists voted in favour of Her2-targeted therapy for these patients. A majority of 62% of the panellists stated that ER-status does not affects this opinion, while 28% of the panellists stated that ER-status will affect their decision on Her2-targeted adjuvant therapy. In line with the previous questions, 52% of the panellists indicated that for patients with ER-positive, Her2-positive breast cancer, addition of pertuzumab to the adjuvant treatment is not a standard therapy.

The preferred regimen for adjuvant therapy in patients with stage 1 Her2-positive breast cancer is, according to 74% of the panellists, taxane plus trastuzumab. Based on the results from the APHINITY trial [1], 77% of the panellists endorsed adding pertuzumab to the adjuvant Her2-targeted therapy for all patients with Her2-positive breast cancer (stage 2 or stage 3, but not in stage 1 patients). This prompted one panellist to remark that the approval for adjuvant therapy with pertuzumab is, according to the results of the APHINITY trial, for (Her2-positive) patients with positive nodes or ER-negative breast cancer.

With regard to the duration of adjuvant therapy with trastuzumab, the vast majority of the panellists (90%) was in favour of 12 months of therapy. A duration of 6-month adjuvant therapy with trastuzumab might be an acceptable option for patients with stage 1 Her2-positive breast cancer, according to 29% of the panellists.

Recently, 1 year of adjuvant therapy with neratinib (after neoadjuvant or adjuvant treatment with trastuzumab) proved to significantly reduce the proportion of clinically relevant breast cancer relapses in patients with Her2-positive, stage 2 or 3 early breast cancer [2]. However, the panellists did absolutely not reach any consensus for which patients adjuvant therapy with neratinib should be recommended both after (neo)adjuvant therapy with trastuzumab and after (neo)adjuvant therapy with trastuzumab plus pertuzumab. About one third of the panellists voted “abstain” on both questions.

  1. von Minckwitz G, et al. N Engl J Med 2017; 377:122-131.
  2. Holmes MM, et al. Lancet Oncol. 2017; 18: 1688-1700.

The content and interpretation of these conference highlights are the views and comments of the speakers/authors.