The major toxicities associated with
paclitaxel(PTX)-based
chemotherapy are myelosuppression,
peripheral neuropathy and
myalgia/
arthralgia. In the present study, a retrospective study was carried out to compare the incidence of adverse events during PTX-based
chemotherapy between 58 cases treated every 3 weeks(tri-weekly regimen)for
breast cancer and
non-small cell lung cancer and 47 cases with weekly regimen for
breast cancer and
gastric cancer. Hematological toxicity such as
neutropenia and
thrombocytopenia,
peripheral neuropathy and
myalgia/
arthralgia occurred more frequently in patients with a tri-weekly regimen than in those with a weekly regimen(grade 3/4
neutropenia: 65.5% versus 12.8%, odds ratio; 12.98, grade 2/3
peripheral neuropathy: 24.1% versus 6.4%, odds ratio; 4.67, and grade 2/3
myalgia/
arthralgia: 43.1% versus 4.3%, odds ratio; 17.05). The development of
peripheral neuropathy and
myalgia/
arthralgia was dependent on the dose per injection, but not on the cumulative dose of PTX. The initial onset of
peripheral neuropathy and
myalgia/
arthralgia was observed in more than 80% of patients during the first course of the tri-weekly regimen, while it was seen in any course of the weekly regimen. The incidence of other nonhematological adverse events was not different between the two regimens except for
nausea. Our present findings suggest that the
peripheral neuropathy and
myalgia/
arthralgia are highly frequent adverse events that depend on the dose per injection of PTX, in which the incidence was more frequent in the tri-weekly than in the weekly regimen.