High-dose chemotherapy and stem cell transplantation for patients with stage IV breast cancer without clinically evident disease: correlation of CD34(+) selection to clinical outcome

Forty-five patients with metastatic breast cancer without clinically eviden t disease were treated with thiotepa 750 mg/m(2), mitoxantrone 40 mg/m(2) a nd carboplatin 1000 mg/m(2) followed by stem cell transplantation to determ ine the safety and efficacy of CD34(+) selection of peripheral blood stem c ells. Of these, 15 patients) (group I) stem cells were processed through Ba xter Isolex 300 device for CD34(+) selection, whereas 30 patients (group II ) received unmanipulated stem cells. Toxicity, progression-free survival an d survival were compared between these two groups. There was no difference in transfusion requirements, white cell count and platelet recovery and non -hematologic toxicity between the two groups. The survival of patients in g roup I was 27 months compared to 38 months in group II (P = 0.8), The progr ession-free survival was 12 months and 13.5 months for group I and group II patients, respectively (P = 0.6). Our results indicate that while there is no adverse effect, there is also no significant advantage of CD34(+) selec tion in terms of progression-free survival and survival in patients with me tastatic breast cancer without clinically evident disease.