Neoadjuvant twelve weekly paclitaxel–carboplatin with trastuzumab and pertuzumab in HER2-positive breast cancer

Abstract Purpose Standard neoadjuvant therapy for early HER2-positive breast cancer consists of 18 weeks of carboplatin, docetaxel, trastuzumab, and pertuzumab. However, treatment intensity may limit feasibility in frail patients and exceed therapeutic needs in selected early-stage disease. We report here real-world clinical outcomes of patients receiving a shortened 12-week neoadjuvant regimen of weekly paclitaxel and carboplatin administered with trastuzumab and pertuzumab (12wTCHP). Methods We conducted a retrospective analysis of patients with HER2-positive breast cancer treated with neoadjuvant 12wTCHP in a single tertiary medical center. Results Of forty-four eligible patients receiving 12wTCHP, 41 had invasive ductal carcinoma (IDC, 93%), and 64% were ER-positive. The majority of the cohort had stage IIA (73%, median age 59 years), while the remainder had stage IIB or stage III disease and were significantly older (median age 64 and 76 years, respectively; p = 0.007). Grade 3–4 neutropenia (20%) and diarrhea (19%) were the most frequent toxicities. No treatment-related deaths occurred. Pathological complete response (pCR) rate was 61%: 54% in ER-positive tumors and 75% in ER-negative tumors ( p = 0.208). After a median follow-up of 30 months, only two recurrences (5%) were observed. None of the 30 patients with stage IIA IDC had disease recurrence. Conclusions In this retrospective cohort study, neoadjuvant 12wTCHP was well tolerated and associated with high pCR and low early recurrence rates. These findings are hypothesis-generating and support further evaluation of de-escalated 12wTCHP regimen in selected patients.