Background: We aimed to clarify the relationship between the maximum tolerated dose and plasma concentration of paclitaxel in Japanese patients with gastric cancer on a weekly paclitaxel administration regimen.
Methods: Thirty-three patients with advanced or recurrent gastric cancer were treated with escalating doses of paclitaxel, administered weekly, along with a fixed dose of 5-fluorouracil or cisplatin.
Results: The plasma concentration of paclitaxel remained above 8.5 ng/ml for 24 h after administration. The mean area under the curve increased significantly with escalating dosage levels (R = 0.63; P 0.001). At level 4, patients showing dose-limiting toxicity had a significantly higher plasma paclitaxel concentration than patients without it.
Conclusion: The weekly administration of paclitaxel, for which a single dose is about one-third of the dose for a tri-weekly treatment regimen, is clinically feasible and appropriate in terms of toxicity and the maintenance of an effective plasma concentration.