Mitoxantrone in elderly patients with advanced breast cancer: Pharmacokinetics, marrow and peripheral hematopoietic progenitor cells

The aims of this study were to evaluate the pharmacokinetics, tolerability and hematopoietic toxicity of mitoxantrone in elderly women. Thirteen patie nts with advanced breast cancer; median age of 73 years, received escalatin g doses of mitoxantrone 8, 10, 12 and 14 mg/m(2) on day 1, q 21. Then was a linear relationship between the mitoxantrone dose administered and the mit oxantrone exposure (AUC) in plasma (r=0.856, pc0.001). After 4 courses of t reatment, a significant decrease in bone man ow cellularity (p=0.0067), and HPC content (BFU-E p=0.0077) was observed. A remarkable, though nor statis tically significant decrease in circulating HPCs was observed after 4 cours es and was still present 8-12 months after the termination of treatment. Th erapy with mitoxantrone in elderly women was well tolerated at the dose of 12 mg/m(2) for forts courses. The significant hematological toxicity observ ed in marrow cellularity and HPC content warrant further studies.