[Clinical study of weekly paclitaxel administration for metastatic breast cancer based on time to progression (TTP)...

We studied 13 women aged 29-62 years for response to weekly administration of paclitaxel for metastatic breast cancer. Paclitaxel was administered by 1-hour intravenous infusion at a dose of 60-80 mg/m2 once a week. Administration was continued for 3 weeks with a 1-week rest for at least 3 cycles. This was first-line treatment in 1 patient, second-line treatment in 7, and third-line treatment in 5. The overall response rate was 68% among 13 partial responders and there were no complete responders. By recurrence site, the response rate was 71% in the liver, 75% in the lung, 18% in bone, and 67% at local sites. Pain was ameliorated in 4 of 8 patients and local recurrence of tumors decreased in 6 of 8 cases. Tumor markers decreased in 6 of 12 cases. Time to progression reached beyond 6 months in 6 of 13 cases, and was limited to within only 3 months in 6 cases. In terms of survival, 4 of 13 patients who were treated by paclitaxel as a 3rd line treatment for liver or lung metastasis died within 3 months after administration. Weekly administration of paclitaxel appears to be effective against metastatic breast cancer. However, the selection of cases based on the timing of administration is considered to be important to prolong the time to progression and improve survival.