Comparison of weekly cisplatin-epirubicin-paclitaxel (PET) with triweekly epirubicin-paclitaxel (ET) in locally advanced breast cancer (LABC). SICOG 9908 phase III tria

Abstract

511 Background: The present study aimed at evaluating whether this new regimen could be more effective than standard triweekly epirubicin/taxol in LABC patients. Patients and Methods: Previously untreated LABC pts (T4 and/or N3), aging ≤ 70 years were eligible. Women were randomised to receive 12 PET (cisplatin 30 mg/m2/week + epirubicin 50 mg/m2/week + paclitaxel 120 mg/m2/week + G-CSF) weekly cycles or 4 triweekly ET (epirubicin 90 mg/m2/ + paclitaxel 175 mg/m2 ) cycles. The pathological Complete Response was the primary endpoint. Results: As of December the 1st 2003, overall 160 patients have been recruited (PET = 78; ET= 82). 140 patients are evaluable for clinical response (PET=69; ET=71), the remaining 20 patients being too early (17) or refusal (3). 20 complete (29%) and 41 partial (59%) responses were recorded in the PET arm, giving a 88% ORR. 11 complete (15%) and 44 partial (62%) responses were observed in the ET arm, giving a 77% ORR. The difference between the two arms was significant as regards the CRR (29% vs. 15%; p=0.05), while there was a trend in favor of the PET arm as regargs the ORR (88% vs 77%; p=0.09) To date, 130 pts have been submitted to surgery. Absence of invasive tumor in the breast (pT0+pTis) was observed in 14 and 10 patients in PET and ET arm, respectively (p=n.s.). Negative axillary nodes (pN0) were found in 17 PET and 14 ET patients (p=n.s.). However, a complete regression of the tumor in both breast and axilla (pT0+pTis+N0) was observed in 11 PET (16%) and only 3 ET (4%) patients (p=0.03). No differences in terms of severe neutropenia and thrombocytopenia were observed between the two arms. However, severe anemia, 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 improve both the clinical and pathological complete response rate in LABC patients when compared with a standard epirubicin/taxol q3wk administration. The accrual still proceeds until the planned sample size of 120 per arm. No significant financial relationships to disclose.