Oral vs. standard chemotherapy to prevent recurrent breast cancer.

Older people are underrepresented in clinical trials, a problem that is particularly acute where it concerns breast cancer. This is a disease that strikes women who are average age 63 years at diagnosis; and the overwhelming majority of deaths occur over the age of 65 years. A new study fills an important information gap about adjuvant drug treatment for older women with breast cancer. It also clears up lingering questions about oral vs. intravenous (IV) chemotherapy.

In 1998, Xeloda (capecitabine) became the first oral chemotherapy drug to be approved by the FDA for metastatic breast, i.e., late-stage cancer that has spread beyond the breast. Xeloda is produced by Roche Laboratories, which partly funded this study, published last month in The New England Journal of Medicine.

Two Questions Asked

Can Xeloda benefit women at earlier stages of breast cancer? How does it compare with standard chemotherapy? These questions were answered by the new study, led by Hyman B. Muss, MD, University of Vermont, Burlington, and conducted at many academic medical centers in the U.S. and Canada.

After their initial treatment for breast cancer, the 600 study participants were randomly assigned to Xeloda or one of two standard IV chemotherapy regimens (One known by the acronym, CMF--cyclophosphamide, methotrexate, and fluorouracil, or another regimen that combines cyclophosphamide and doxorubicin). The participants had been diagnosed with breast cancers that ranged from stage I through stage IIIB.

First, the researchers looked at the number of participants who were recurrence-free at 3 years. It was 68% of the women in the Xeloda group and 85% of the women in the IV chemotherapy group.

When the researchers looked at overall survival, IV chemotherapy again proved better than Xeloda. The survival rate at three years was 86% for the women in the Xeloda group versus 91% for those in the IV chemotherapy group. Two women in the Xeloda group died of treatment-related complications.

More Toxic Effects With Chemo

Although IV chemotherapy came out on top regarding recurrence and survival, it was worse when it came to side effects. Twice as many women in the chemotherapy group suffered moderate to severe toxic effects, such as nausea and vomiting (64% vs. 33%). More women on IV chemotherapy (38%) could not complete the six cycles of treatment because of severe toxic side effects, compared with 20% who could not finish the six planned cycles of Xeloda.

The greatest benefit to taking Xeloda was shown for the women in this trial who had hormone-receptor negative tumors. This is consistent with the results from earlier research conducted at Oxford University.

The new study provides more fodder for the contentious issue of drug costs. Both private and public health plans in the U.S. are requiring patients to pay more out of pocket for cancer drugs. Many plans, including Medicare, will reimburse for IV drugs, but not for oral drugs. This leads some cancer patients to suspect that they are being steered away from the newer and better oral drugs for cost-saving reasons.

Maryann Napoli, Center for Medical Consumers [C] 2009

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