Phase III trial of doxorubicin, paclitaxel, and the combination of doxorubicin and paclitaxel as front-line chemotherapy for metastatic breast cancer: An intergroup trial (E1193)

Purpose : Between February 1993 and September 1995, 739 patients with metastatic breast cancer were entered on an Intergroup trial (E 1193) comparing doxorubicin (60 mg/ m(2)), paclitaxel (175 mg/m(2)/24 h), and the combination of doxrubicin and paclitaxel (AT, 50 mg/m(2) and 150 mg/ m(2)/24 h, plus granulocyte colony-stimulating factor 5 mg/ kg) as first-line therapy. Patients receiving single-agent doxorubicin or paclitaxel were crossed over to the other agent at time of progression. Patients and Methods: Patients were well balanced for on-study characteristics. Results: Responses (complete response and partial response) were seen in 36% of doxrubicin, 34% of paclitaxel, and 479% of AT patients (P =.84 for doxorubicin v paclitaxel, P =.007 for vAT, P =.004 for paclitaxel vAT). Median time to treatment failure (TTF) is 5.8, 6.0, and 8.0 months for doxorubicin, paclitaxel, and AT, respectively (P =.68 for doxorubicin v paclitaxel, P =.003 for doxorubicin v AT, P =.009 for paclitaxel v AT). Median survivals are 18.9 months for patients taking doxorubicin, 22.2 months for patients taking paclitaxel, and 22.0 months for patients taking AT (P = not significant). Responses were seen in 20% of patients crossing from doxrubicin --> paclitaxel and 22% of patients crossing from paclitaxel --> doxorubicin (P = not significant). Changes in global quality-of-life measurements from on-study to week 16 were similar in all three groups. Conclusion: (1) doxorubicin and paclitaxel, in the doses used here, have equivalent activity, (2) the combination of AT results in superior overall response rates and time to TTF; and (3) despite these results, combination therapy with AT did not improve either survival or quality of life compared to sequential single-agent therapy.