High-dose consolidation therapy with autologous stem cell rescue in stage IV breast cancer.

We designed a phase II study to determine whether induction chemotherapy (CT) consisting of leucovorin, vincristine, methotrexate, doxorubicin, and cyclophosphamide (LOMAC) followed by high-dose intensification chemotherapy (ICT) with cyclophosphamide, thiotepa, and autologous stem cell rescue (ASCR) could increase the complete response (CR) rate and survival in women with stage IV breast cancer. Twenty-nine women were enrolled on study; 16 patients had received prior adjuvant chemotherapy and no patient had received chemotherapy for stage IV disease. Two patients were found to be ineligible and excluded from further analysis. Of the 27 patients treated, four (15%) obtained a CR and 15 (56%) a partial response (PR) after LOMAC induction, for an overall response rate of 70%. Of the 22 patients treated with ICT, 12 patients had a CR, and nine were in PR after induction and converted to CR after ICT. The toxicities included nausea/vomiting, mucositis, diarrhea, dermatitis, alopecia, and infections secondary to neutropenia. The 1-year survival is 60%; the median has not yet been reached. The time to treatment failure for patients on study is 10 months. The treatment approach of ICT and ASCR following induction chemotherapy can lead to an improved CR rate in stage IV breast cancer. How this increased CR rate leads to a prolonged disease-free survival requires further follow-up.