Preoperative Weekly Cisplatin, Epirubicin, and Paclitaxel (PET) Improves Prognosis in Locally Advanced Breast Cancer Patients: an Update of the Southern Italy Cooperative Oncology Group (SICOG) Randomised Trial 9908

Background: The present article reports the updated survival outcome of the 200 patients enrolled in the Southern Italy Cooperative Oncology Group 9908 trial, which compared 12 weekly cycles of cisplatin-epirubicin-paclitaxel (PET) with 4 triweekly (once every 3 weeks) cycles of epirubicin-paclitaxel (ET) in patients with locally advanced breast cancer (LABC).

Methods: The effects of treatment, pathologically documented response (pathological response), pre- and post-treatment biomarkers on relapse-free survival (RFS), distant metastasis-free survival (DMFS), and overall survival (OS) are analysed.

Results: At a median follow-up of 74 (range 48-105 months) months, the 5-year RFS, DMFS, and OS were 64 % versus 53% (P = 0.11), 73% versus 55% (P = 0.04), and 82% versus 69% (P = 0.07) in PET and ET, respectively. At multivariate analysis, after adjusting treatment effect for pretreatment biomarkers, PET independently predicted better DMFS (P = 0.018) and OS (P = 0.03), whereas the impact on RFS was of borderline significance (0.057). PET treatment was significantly better than ET treatment only in high-grade or highly proliferating tumours. The better outcome in PET arm was the results of both the higher rate of patients with optimal pathological response and the lower rate of patients with biologically aggressive residual tumour.

Conclusions: The PET weekly regimen significantly improves both DMFS and OS in LABC patients, compared with the triweekly ET combination. The therapeutic advantage is limited to patients with highly aggressive tumours.