Abstract 166P
Background
The APHINITY trial showed that an addition of 1 year pertuzumab (P) to standard chemotherapy with trastuzumab (T) improves invasive disease-free survival in HER2+ breast cancer patient with node-positive. Meanwhile, in patients with pathologic complete response (pCR) after neoadjuvant chemotherapy (NACT) with TP, it lacks of evidence whether an addition of P might be omitted in adjuvant treatment. We compared survival outcome according to the type of adjuvant anti-HER2 therapy in patients with pCR after NACT with TP.
Methods
We included the patients who achieved pCR in both breast and axilla after NACT plus TP. The recurrence-free survival (RFS) was defined as the interval between operation and recurrence or last censored. The 3-years RFS was compared between two groups by adjuvant anti-HER2 therapy (TP and T).
Results
A total of 381 patients were included. Of these, 47 (12.1%) patients received adjuvant TP, while 334 (87.9%) were treated adjuvant T alone. At an initial diagnosis, clinical stage, clinical nodal status, and ER-positive rate was not different between two groups. At a median follow up of 36 months, the 3 year-RFS was 93.9% in all patients. In all patients, the 3-years RFS did not differ between two groups (91.7% in TP and 94.2% in T). In clinical node-positive group (n=293), there were no survival difference between two groups (90.4% in TP and 93.2% in T).
Conclusions
In patients with pCR responded to chemotherapy and dual HER2- blockade, 3 years RFS was excellent and did not differ according to the type of adjuvant anti-HER2 therapy (TP vs T). Our findings provide a tailored strategy for exploring adjuvant pertuzumab de-escalation in excellent responders identified by surgery after NACT plus TP.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
S.G. Ahn: Financial Interests, Personal, Stocks/Shares: Genopeak. All other authors have declared no conflicts of interest.