Combined chemotherapy in patients with metastatic breast cancer

This study examined the effects of a combination of two treatments, low-dose capecitabine (Xeloda) and docetaxel (Taxotere), versus docetaxel alone in patients with metastatic, HER2-negative breast cancer. The study concluded that combination treatment improved time to disease progression.

Chemotherapy is a main treatment option for metastatic (spread beyond the breast) breast cancer. Chemotherapies such as capecitabine and docetaxel block the division and growth of cancer cells. Previous studies noted that a combination of these treatments improved progression free survival (PFS; time from treatment to disease progression). The combination also increased severe side effects compared to treatment with docetaxel alone. Lowering the treatment doses has been found to decrease the severity of the side effects. It is not clear whether lower-dose combination chemotherapy is as effective as a higher dose of docetaxel alone.  

This study compared a lower-dose combination of capecitabine and docetaxel to docetaxel alone. This study included 162 Japanese women. All patients had metastatic, HER2-negative breast cancer. All patients had already been treated with anthracyclines (a type of chemotherapy). The participants were randomly assigned to either combination treatment (82 patients) or docetaxel alone (80 patients). Patients were followed for an average of 18.4 months.

The average time to disease progression was 10.5 months with combination treatment and 9.8 months with docetaxel alone. Disease progression was 38% less likely in patients treated with the combination.

40% of patients treated with docetaxel alone were treated with capecitabine alone after disease progression. There was no difference in PFS between these patients and those receiving the combination treatment.

The two groups had a similar rate of severe side effects. Hand-foot syndrome (redness, swelling, or pain in the hands or feet) occurred more often in the combination group (7.3%). There were no cases in the docetaxel group. Fatigue occurred in 2.4% of the combination group and 10% of the docetaxel group. 100% of patients undergoing combination therapy required a lower dose, compared with 49% of patients treated with docetaxel alone. 21% of patients in the combination group stopped treatment due to side effects, compared to 34% of those treated with docetaxel alone.

The study concluded that PFS was improved in patients undergoing low-dose combination therapy, compared with those treated with docetaxel alone.

This study took the form of an open-label trial, meaning that both the researchers and participants were aware of which treatment they were receiving. This could lead to bias in the results.

This study was funded by Chugai Pharmaceuticals, a subsidiary of Hoffmann-La Roche. Hoffmann-La Roche manufactures capecitabine. 

Discuss the effects of combination treatments with your physician.