WASHINGTON Many women with breast cancer may be able to safely skip at least one step in chemotherapy, saving themselves time and side-effects, U.S. researchers said on Wednesday.
Women in a study with so-called estrogen-receptor positive cancers did not gain any added benefit from taking Taxol, which can cause nausea, hair loss, severe hypersensitivity reactions and other side-effects.
But those with HER2-receptor-positive cancer -- about 15 to 20 percent of women with breast cancer -- were significantly helped when Taxol was added, Dr. Daniel Hayes of the University of Michigan and colleagues reported in the New England Journal of Medicine. They had a 41 percent lower rate of having their cancer come back.
"If you ask how much longer am I going to live disease free, it's about 3 years ... and that's huge," Donald Berry of the University of Texas M. D. Anderson Cancer Center, who helped direct the study, said in a telephone interview.
While they are not recommending any changes in practice yet, the researchers say doctors should be aware of their findings in discussing treatments with patients.
"In general, chemotherapy for breast cancer has been a one-size-fits-all approach," Hayes said in a statement.
Doctors usually add more chemotherapy agents if they believe the cancer is likely to have spread. Taxol, known generically as paclitaxel, or related drugs in a class called taxanes are usually added to a cocktail of other drugs.
The researchers had been studying a group of women for years, many of whom got Taxol after going through four cycles of the drugs adriamycin and cytoxan for breast cancer that had spread to their lymph nodes.
They tested the original tumor tissue of 1,322 women to see who had estrogen-positive cancer and who had another type, called HER2-receptor-positive cancer.
Then they looked at how the women did up to 12 years later. Those with HER2 tumors got clear benefits.
"But paclitaxel did not benefit patients with HER2-negative, estrogen-receptor-positive cancer," they wrote.
"Why should we spare our patients from paclitaxel?" Dr. Anne Moore, of Weill Cornell Medical College wrote in a commentary.
Side-effects, cost and convenience, answered the researchers.
"Neurotoxicity is the big one," Berry said. "It can be very bad if you don't know your feet are there."
Breast cancer patients also have options of newer drugs, such as Herceptin, which is targeted to HER2-positive tumors.