Docetaxel Regimen Better Tolerated Than Doxorubicin in Adjuvant Breast Cancer Setting

SAN FRANCISCO—Results are now emerging regarding the use of docetaxel (Taxotere) in the adjuvant breast cancer setting. A large study presented at the 37^th Annual Meeting of the American Society of Clinical Oncology (ASCO) evaluated the adjuvant use of docetaxel plus cyclophosphamide (TC 75/600 mg/m²) and found it to be better tolerated than standard doxorubicin (Adriamycin) plus cyclophosphamide (AC 60/600 mg/m²).

Principal investigator S.E. Jones, MD, director of breast cancer research for Baylor-Sammons Cancer Center, Dallas, and US Oncology, reported the findings at the meeting.

The study aimed to test the efficacy of a nonanthracycline regimen in the adjuvant treatment of operable breast cancer. The study randomized 1,016 patients to four courses of either regimen every 3 weeks preceding adjuvant radiation therapy and tamoxifen (Nolvadex) as indicated. Most patients had tumors less than 5 cm; 57% had negative nodes, and 41% had one to three positive nodes.

"Because of cardiotoxicity and the fact that Taxotere is more active than Adriamycin as a single agent in metastatic disease, it made sense to look at Taxotere/cyclophosphamide vs Adriamycin/cyclophosphamide," Dr. Jones said.

This study, now with more than 2 years of follow-up, appears to be the first to come to maturity for docetaxel in the adjuvant setting.

At a median follow-up of 27 months, the TC regimen was better tolerated. TC was associated with the typical docetaxel-type side effects, such as paresthesias, edema, weight gain, rash, and arthralgias, which were mild and reversible. AC was associated with more nausea, vomiting, stomatitis, and anemia. Grade 3-4 leukopenia, infections, asthenia, and hair loss were similar, and one AC patient developed congestive heart failure.

Dr. Jones commented on the tolerability of the regimen. "We showed that Taxotere/cyclophosphamide produced significantly fewer of the side effects that are important to patients, such as nausea, vomiting, mouth sores, and anemia, than did standard Adriamycin/cyclophosphamide," he said.

There have been fewer relapses in the TC arm (17 vs 24 for AC) and fewer deaths from any cause (11 vs 16), in this preliminary analysis. Response rates have not yet been determined.