CHICAGO -- An updated analysis of two large randomized clinical trials has found that breast cancer patients who received the monoclonal antibody trastuzumab (Herceptin) along with chemotherapy are living longer and with less risk of recurrent disease, compared to patients treated with chemotherapy alone.

These studies, sponsored by the National Cancer Institute (NCI), were undertaken to test whether trastuzumab adds to the benefit of adjuvant chemotherapy (doxorubicin, known as Adriamycin, and cyclophosphamide) followed by paclitaxel (Taxol) in women with HER2 + breast cancer who have undergone surgery. Trastuzumab treats the approximately 20 percent of tumors that are HER2 +, that is, their cancer makes too much of the surface protein HER2, which tends to make the cancer grow faster and recur more often than tumors that are not HER2 +.

Four years of follow-up data have concluded that 85.9 percent of 1,989 women treated with trastuzumab are cancer free and 92.6 percent are alive, compared with 73.1 percent and 89.4 percent, respectively, of 1,979 women who were not treated with the monoclonal antibody. In all, 397 patients in the chemotherapy group have developed a recurrent tumor or have died, compared to only 222 in the trastuzumab group.

These results mean that the hazard of disease recurrence is decreased by 52 percent with the addition of trastuzumab to chemotherapy and that trastuzumab therapy was associated with a 35 percent reduction in the risk of death, according to Edith Perez, M.D., director of Mayo Clinics Multidisciplinary Breast Clinic in Jacksonville, Fla., and primary investigator of one of the trials. She is presenting results of the joint analysis at the annual meeting of the American Society of Clinical Oncology (ASCO).

Trastuzumab has revolutionized the care of HER2 + breast cancer, and this study clearly shows the statistical and clinical significance of the therapy, says Dr. Perez.

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Contact: Nancy Jensen
newsburea@mayo.edu
904-953-2299
Mayo Clinic
4-Jun-2007