[Relation of dose intensity and efficacy, toxicity in paclitaxel as a single agent for advanced breast cancer]

To evaluate the relation of dose intensity and efficacy, toxicity in advanced breast cancer treated with paclitaxel as a single agent.

Seventy-one patients with advanced breast cancer received paclitaxel as a single agent with different dose intensities. According to the phase I or phase II trial, the standard dose intensity of paclitaxel was defined as 58.3 mg.(m(2))(-1).week(-1). The dose of paclitaxel was 175 mg/m(2) given every three weeks, ranging 33.3 - 70.3 mg.(m(2))(-1).week(-1) [median delivered dose intensity 58.82 mg.(m(2))(-1).week(-1)]. Efficacy and toxicity was evaluated.

The overall response rate in this group of advanced breast cancer was 40.8%. Responses were seen in lungs, soft tissue, bone and liver, with the response rates of 52.0%, 38.0%, 12.5%, 7.7%, respectively. When the relative dose intensity (RDI) was > 1.0, 0.9 - 1.0, < 0.9, the response rates were 44.2%, 47.6%, 0, respectively. The difference between the group (RDI >/= 0.9% - 1.0%) in 7 patients and the group (RDI < 0.9) was significant (P < 0.05). Toxicity was well tolerated, with the efficacy decreased as soon as the RDI had been reduced without embarrassing the toxicity.

Paclitaxel as a single agent therapy with standard dose intensity is effective and well tolerated by patients with advanced breast cancer.