Prospective study of paclitaxel-induced peripheral neuropathy with quantitative sensory testing

Background. Paclitaxel-induced peripheral neuropathy (PN) may be severeand dose-limiting at initial doses ≥ 275 mg/M2, but itsneurotoxicity at doses ≤ 250 mg/M2 has been incompletelycharacterized. The purposes of this study were to characterize and quantifypaclitaxel-induced PN and to determine the utility of quantitative sensorytesting (QST). Methods. We prospectively examined clinically and by QST 37women with metastatic breast cancer, treated with paclitaxel (200–250mg/m2) (average number of cycles = 7.3 over an average of 20.1weeks). QST included thermal threshold (TT) and vibration threshold (VT).Results. Paresthesias appeared in 31 (84%) patients after an averageof 1.7 cycles and an average cumulative dose of 371.5 mg/M2. Symptomsoccurred after the first or second dose in 26 (84%) patients and thenstabilized in 10 (32%), improved in 13 (42%) despite continuedtreatment, resolved completely in 6 (19%), and were progressive in 2(7%). Paclitaxel was discontinued in only 1 (3%) patientbecause of neurotoxicity and no patient required dose reduction because ofPN. Thirty-six (97%) developed signs of PN. The most sensitive QSTwas great toe VT but QST did not predict or identify subclinical PN in anypatient. Neurologic syndromes other than PN developed in 12 (32%)patients, and 7 were due to metastatic cancer. Conclusions. 1)Paclitaxel-induced PN is mostly sensory, and begins after the first orsecond dose. At these doses the neuropathy is mild, and rarelydose-limiting. 2) QST quantified the neuropathy but was less sensitive thanthe clinical examination. 3) Knowledge of the features of paclitaxel's PNallows it to be differentiated from other neurologic syndromes which maysignal tumor progression.