Weekly cisplatin-epirubicin-paclitaxel (PET) vs. triweekly epirubicin-paclitaxel (ET) in metastatic breast cancer (MBC). Interim analysis of the SICOG 9908 phase III trial

Abstract

640 Background: The present study aimed at evaluating whether the PET weekly regimen could produce a significant prolongation of TTF in MBC patients in comparison with standard 3-weekly epirubicin-taxol administration. Patients and Methods: Previously untreated metastatic BC pts, aging ≤ 70 years, and with ECOG P.S. ≤ 2 were eligible. Women were randomised to receive 12 weekly PET (cisplatin 30 mg/m2/week + epirubicin 50 gm/m2/week + paclitaxel 120 mg/m2/week + G-CSF) cycles or 6 triweekly ET (epirubicin 90 mg/m2/ + paclitaxel 175 mg/m2 ) cycles. The Time to Treatment Failure was considered the main end point. An accrual of 120 patients per arm was planned, with an interim analysis on the first 60 evaluable patients of each arm, according to the Shaid's design. Results: As of December the 1st 2003, overall 132 patients have been recruited (PET=64; ET=68). 120 patients are evaluable for clinical response, the remaining 12 patients being too early (10) or not evaluable (2) since they were lost to follow-up. 11 Complete (20%) and 34 partial (60%) responses were recorded in the PET arm, giving a 80% ORR. 8 Complete (12%) and 24 partial (38%) responses were registered in the ET arm, for a 50% ORR; (p=0.0004) At a median follow-up of 21 (range:1–48) months, 78 failures have occurred (PET=38; ET=40), median TTF being 13.2 months and 14 months in PET and ET arm, respectively (p=0.97). Only 43 deaths occurred (PET 18, ET 25), 4-year survival probability being: PET= 44 %; ET= 39 %. Anaemia, mucositis, peripheral neuropathy, and gastrointestinal toxicity were substantially more frequent in the PET arm. Conclusions: According to these preliminary data, the PET weekly regimen can significantly increase the probability of achieving a major response in patients with metastatic breast cancer when compared with a standard triweekly ET regimen. However, both the Clinical Complete Response rate and Time to Treatment Failure are not significantly different in the two arms; moreover, anemia and nonhematological toxicity were sometimes relevant in the PET arm. The accrual still proceeds until the planned sample size No significant financial relationships to disclose.