Trastuzumab Cuts Down Gravely Recurrence Rate

Trastuzumab seems to hold cancer
cells at bay; © NCI Visuals Online

In a joint paper, co-authored by Mayo Clinic’s Edith Perez, M.D., and Edward Romond, M.D., of the National Surgical Adjuvant Breast and Bowel Project (NSABP), researchers report complete and combined results of two trials comparing adjuvant chemotherapy with or without concurrent trastuzumab treatment in women with surgically removed HER2-positive breast cancer.

“Trastuzumab has changed the treatment of breast cancer,” says Perez, who is the co-director of Mayo Clinic’s Multidisciplinary Breast Clinic in Jacksonville, Fla. “When we started this study, I knew in my heart results would be positive, but this by far exceeded my expectations.”

Of the 2,043 patients enrolled in NSABP trial B-31 and 1,633 patients enrolled in the two reported treatment groups of the North Central Cancer Treatment Group (NCCTG ) trial N9831 by the end of 2004, complete follow-up information was available on 3,351 patients. Two hundred sixty-one women in the control group (1,679 patients) had a recurrence of breast or other primary cancer as compared to 133 in the group receiving trastuzumab.

At three years, 90.4 percent of women receiving trastuzumab were disease free, compared to 81.5 percent of women in the control group. There also was a measurable reduction in the development of other non-breast primary cancers in the B-31 trial for women receiving trastuzumab. Overall survival also appeared to be impacted, with only 62 deaths in the trastuzumab group as compared with 92 in the control group.

Dr. Perez and her co-investigators found convincing evidence that women with HER2-positive breast cancer can now be treated more effectively. “A million women each year are diagnosed with breast cancer throughout the world, and approximately 25 percent of them have HER2 tumours,” says Perez.; Source: Mayo Clinic