Safe de-escalation of chemotherapy in HER2-positive early breast cancer
Mené dans 7 pays européens sur 356 patientes atteintes d'un cancer du sein HER2+ de stade précoce, cet essai de phase II évalue l'efficacité, du point de vue de la survie sans maladie à 3 ans, et la toxicité d'une stratégie thérapeutique adaptée en fonction du taux de réponse complète mesuré par tomographie numérique par émission de positrons avec injection de fluorodésoxyglucose F18 (stratégie à base de trastuzumab, pertuzumab avec ou sans thérapie endocrinienne ou stratégie à base de trastuzumab, pertuzumab et chimiothérapie)
Targeted therapy for HER2-positive early and metastatic breast cancer has been one of the cancer success stories of the 21st century, as part of a paradigm shift towards precision cancer medicine. The Early Breast Cancer Trialists' Collaborative Group overview showed that adjuvant trastuzumab when added to chemotherapy improved long-term outcomes for patients with an absolute benefit of 9·0%. 1 In addition, anti-HER2 directed therapy has altered the shape of the Kaplan–Meier survival curves, so not only has the frequency of metastatic relapse dramatically decreased, but the annual hazard rate of relapse in the first 5 years is also considerably lower when compared with the pre-trastuzumab era. 2 , 3 Neoadjuvant trastuzumab and pertuzumab with chemotherapy followed by both antibodies in the adjuvant setting is now the standard of care for many with early HER2-positive breast cancer. After neoadjuvant treatment, pathological complete response (pCR) at surgery has proved to be an excellent surrogate for the prediction of long-term outcomes in women with HER2-positive breast cancer. Correlation of achieving a pCR with disease-free survival and overall survival has been confirmed in two meta-analyses. 4 , 5 The NeoSPHERE trial showed high pCR rates to dual antibody therapy (trastuzumab and pertuzumab) with chemotherapy. 6 Neoadjuvant trastuzumab and pertuzumab without chemotherapy had previously been included as a randomised group in the NeoSPHERE trial. 6 However, the pCR rate proved to be low at 16·8%, and in addition all patients received a full course of adjuvant chemotherapy with trastuzumab and pertuzumab after surgery, thus not avoiding chemotherapy.