Post(-neo)adjuvante Therapiestrategien – Möglichkeiten der Individualisierung

Neoadjuvant chemotherapy (NACT), with or without antibodies or immunotherapy, is indicated particularly in aggressive breast cancer subtypes before surgery. Pathological complete response (pCR) after NACT is associated with an improved prognosis. Thanks to modern treatment options, up to 60–70% of patients achieve pCR in clinical trials. “Post-neoadjuvant” refers to therapeutic strategies that are administered postoperatively depending on the response to the previously applied neoadjuvant treatment. Which post-neoadjuvant treatment is recommended depends on the tumor biology. In HER2-positive disease with non-pCR, post-neoadjuvant therapy consists of the antibody–drug conjugate T‑DM1. Several options are available for patients with triple-negative breast cancer and non-pCR. If the immune checkpoint inhibitor pembrolizumab was given during neoadjuvant chemotherapy, it can be continued after surgery. Another option is oral chemotherapy with capecitabine. In case of a BRCA1/2 mutation, the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib may be recommended. To what extent these substances can/should be combined with each other remains to be clarified. There is still no well-established post-neoadjuvant strategy for hormone receptor-positive HER2-negative breast cancer. The cyclin-dependent kinase (CDK)4/6 inhibitor abemaciclib is recommended in the adjuvant and post-neoadjuvant setting for patients with high-risk breast cancer. In patients with a BRCA1/2 mutation and a very high risk of relapse (defined as a CPS - EG score of at least 3, based on pre-treatment clinical [CS] and post-treatment pathological stage [PS], estrogen receptor status [E], and grade [G]), olaparib can be administered in case of non-pCR.