Does induction chemotherapy with a mitoxantrone/vinorelbine regimen allow a breast-conservative treatment in patients with operable locoregional breast cancer? A French Northern Oncology Group trial in 105 patients

Background: In recent years, induction chemotherapy has been tested by several investigators in the management of operable breast cancer. Patients and methods. Our current study was aimed to evaluate, pragmatically, in patients (74 stage II and 30 stage III) whose treatment would have been mastectomy, the percentage of them in whom a conservative treatment can be performed if primarily treated with a mitoxantrone/vinorelbine regimen. Results: 67/104 patients (64%; 95% CI: 55-74%) had a conservative treatment (lumpectomy: 54, radiation therapy: 12, radiation therapy then lumpectomy: 1). Neutropenia was the major dose-limiting side effect, with grade 3 or 4 neutropenia registered in 83% of patients and 53.3% of the 442 cycles. Overall, a grade 3 or 4 non hematologic side effect occurred in 19.8% of patients and in 9.1% of cycles. One toxic death was observed after 2 cycles in a patient with aplasia who developped septicemia. Seventy one per cent of the patients experienced nausea and vomiting but grade 3 were observed in only 12% of the patients, Other side effects, including stomatitis, asthenia, alopecia, and constipation, were generally mild and uncommon. Conclusions: This mitoxantrone/vinorelbine regimen is an efficient induction treatment with only neutropenia as a noticeable side effect, It allows 64% of conservative treatment in patients whose treatment would have been mastectomy.