Standard chemotherapy was superior to capecitabine in older patients

Women aged 65 years and older with breast cancer who were treated with capecitabine had lower rates of relapse-free survival and overall survival than similar patients treated with standard chemotherapy, according to Hyman Muss, MD.

Muss, a professor of medicine at the Vermont Cancer Center in Burlington, presented the results of the CALGB/CTSU 49907 trial at the 2008 ASCO Annual Meeting in Chicago.

Muss and colleagues stratified women by age, cancer status and HER-2 status, then randomly assigned them into either the capecitabine arm (n=307) or the standard chemotherapy arm (n=326). Patients in the standard arm then received either cyclophosphamide, methotrexate and 5-FU or cyclophosphamide and doxorubicin.

CMF was administered in standard doses for six cycles repeated every six weeks. AC was administered in standard doses for four cycles repeated every three weeks.

The researchers administered 2,000 mg/m² capecitabine (Xeloda, Roche) in two divided doses for 14 consecutive days every three weeks for six cycles.

At the time of first analysis, 89% of patients in the standard chemotherapy arm were still alive and 11% had relapsed, compared with 80% of patients in the capecitabine arm who were still alive and 20% who had relapsed.

The researchers concluded that patients in the capecitabine arm had more than twice the risk of relapse compared with those receiving standard chemotherapy (HR=2.09; 95% CI, 1.4-3.2).

They determined that those in the standard chemotherapy arm also had a better overall survival (HR=1.85; 95% CI, 1.1-3.1). Twenty-four patients in the standard chemotherapy arm died during the trial; eight (33%) died of breast cancer. In comparison, 36 patients in the capecitabine arm died; 18 (50%) died of breast cancer. – by Jason Harris

The study results are likely correct: Single-agent capecitabine would appear to be inferior to conventional combination chemotherapy in the adjuvant treatment of older patients with early-stage breast cancer. There is a chance the results arose due to the play of random chance, but not likely. There was a conclusion Muss et al did not make that I think they would have been justified in making. Their data make it quite likely that there is an adjuvant benefit for chemotherapy in older patients. The only other reasonable interpretation is that capecitabine in this dosing schedule somehow took away from the natural history of breast cancer in these older patients.

– John Crown, MD

Professor of Medicine at St. Vincent’s University Hospital, Dublin, Ireland

Vice Chair of the Ireland Clinical Oncology Research Group

For more information:
Muss HB, Berry DL, Cirrincione C. #507. Presented at: 2008 ASCO Annual Meeting; May 30-June 2, 2008; Chicago.