Prospective evaluation of the pharmacokinetics and toxicity profile of docetaxel in the elderly

Purpose To prospectively study the pharmacokinetics and toxicity profile of docetaxel in elderly patients with cancer. Patients and Methods Docetaxel was administered at a dose 75 mg/m(2) once every 3 weeks to 25 elderly cancer patients aged greater than or equal to 65 years and 26 cancer patients aged younger than 65 years. Pharmacokinetic studies and toxicity assessments were performed during the first cycle of therapy. Results Of 51 patients treated, 20 aged greater than or equal to 65 years (median, 71 years; range, 65 to 80 years) and 20 aged younger than 65 years (median, 53 years, range, 26 to 64 years) were assessable for pharmacokinetic studies, and 39 were assessable for toxicity. Patient characteristics were similar (P greater than or equal to .15) between the two cohorts. Mean docetaxel clearance was not altered in the elderly versus younger patients: 30.1 L/h (standard deviation [SDI 18.3 L/h) v 30.0 L/h (SD, 14.8 L/h; P = .98). The percentage of patients with grade 4 and febrile neutropenia was higher in the elderly (63% and 16%, respectively) versus younger (30% and 0%, respectively) cohort, although this observation did not reach a level of statistical significance (P = .056). From logistic regression analysis, the odds ratio for a patient aged 65 years was 1.98 for developing grade 4 neutropenia compared with a patient aged 50 years (P = .091). Conclusion Docetaxel plasma pharmacokinetics are unaltered in elderly patients. Patients aged greater than or equal to 65 years appear to be more sensitive to docetaxel-induced neutropenia. (C) 2005 by American Society of Clinical Oncology.