Breast Cancer Chemo Drug for Whom?

Oct. 10, 2007 -- The breast cancer chemotherapy drug Taxol may not help most breast cancer patients, researchers report in The New England Journal of Medicine.

The key finding: Adding Taxol to a chemotherapy regimen may only benefit women who have HER2-positive breast cancer, in which breast cancer has a high level of a protein called HER2.

That's about 15% to 20% of all breast cancer patients, according to the researchers, who included the University of Michigan's Daniel Hayes, MD.

Hayes' team isn't recommending that any breast cancer patients abandon Taxol.

"We think the stakes are too high" to change treatment recommendations until further research is done, Hayes says in a news release.

But cancer doctors "have a responsibility to patients to be aware" of the study, states a journal editorial.

"The days of 'one size fits all' therapy for patients with breast cancer are coming to an end," writes editorialist Anne Moore, MD, of New York's Weill Cornell Medical College.

Taxol for Breast Cancer

Hayes and colleagues reviewed data from a breast cancer study conducted in the 1990s.

Though the data weren't new, the analysis was, and it was "appropriate" to look back at that data, according to editorialist Moore.

The study included 3,121 women whose breast cancer had spread to their lymph nodes and who had already had breast cancer surgery.

All of the women got two chemotherapy drugs -- Adriamycin and Cytoxan. Afterward, about half of the women got further chemotherapy treatment with Taxol.

Taxol and HER2

Over the next five years, women with HER2-positive breast cancer who got Taxol were more likely to survive without breast cancer recurrence, compared with those with HER2-positive breast cancer who didn't get Taxol.

But those Taxol benefits only included women with HER2-positive breast cancer, the study shows. In women with HER2-negative breast cancer, Taxol didn't appear to affect survival or recurrence.

The findings weren't affected by whether the women's breast tumors were sensitive to the hormone estrogen.

In the journal, several of Hayes' colleagues report financial ties to Bristol-Myers Squibb, the drug company that makes Taxol.