Neoadjuvant chemotherapy based on dose-dense epirubicin (E) plus cyclophosphamide (C) followed by docetaxel (D) plus trastuzumab (T), DT plus carboplatin (CBDCA), or DT plus HER2 double blockade in HER2-positive breast cancer patients
Background: Amplification of the HER-2 gene occurs in 20% of breast cancer (BC) patients (pts). Trastuzumab administered concurrently with chemotherapy (CT) is the standard of care in the neoadjuvant setting. Moreover, the use of a combination of antiHER2 therapies with CT are related to an increased pCR, which could be a surrogate marker for survival. Methods: We retrospectively analyzed three historic cohorts with overexpressing HER2 BC. They received neoadjuvant CT based on dose dense anthracyclines followed by three schedules of antiHER2 therapy: 1) docetaxel plus trastuzumab (DT; n = 33 pts); 2) DT plus CBDCA (DTP; n = 17 pts); and 3) DT plus double blockade with triweekly pertuzumab or daily L (750mg/day; n = 12) (DTD; n = 14) before surgery. Study endpoints were safety, pCR (breast + axilla) based on Miller&Payne criteria and DFS. Results: Sixty-four pts with HER2 overexpressing BC were studied since 2005. Baseline characteristics were well balanced. The median age was 48 (range 23-80). Coexpression of ER and HER2 in each cohort was 48% in DT, 53%% in DTP and 57% DTD (p = 0.855) as well as initial BC stages (p = 0.64). Grade 3-4 toxicity in DT, DTP and DTD were respectively: asthenia 0%, 5.8% and 0% (p = 0.71), hand-foot syndrome 3%, 5.8% and 0% in DT, DTP and DTD (p = 0.719), anemia 0%, 5.8% and 0% (p = 0.71) leukopenia 6%, 11.7% and 0% in DTD (p = 0.60) and diarrhea in 35.7% in DTD (p = 0.002). We did not find differences in pCR (42.4% in the DT, 29.4%% in the DTP and 42.8% in DTD cohorts; p = 0.67), axillar response (type D) was significantly superior in the DTD cohort with the followed distribution of 51.1%, 52.9% and 85.7% respectively (p = 0.04). However breast responses were similar in the three cohorts (p = 0.9). With a median follow-up of 72, 90 and 21 months respectively, the number of pts who progressed were 12.1%, 11.7% and 0% in DT, DTP and DTD. Conclusions: We did not find differences in pCR in any cohort. The best significant axillary responses were in the DTD cohort, however this fact did not impact in total pCR. DTD cohort has more gastrointestinal toxicity. To date, median survival has not been reached.