All had additional drug treatments, including chemotherapy and/or up to five
years of therapy with the anti-estrogen drug tamoxifen.
Over the next decade after drug treatment, one in five of the women
experienced a recurrence of her breast cancer.
"The risk of relapse was still small, but certainly not
insignificant," M.D. Anderson breast oncologist and study researcher Abenaa
M. Brewster, MD, tells WebMD. "I think these numbers are somewhat
reassuring, but they also highlight the need for new [therapeutic] options for
women who have completed five years of treatment."
Breast Cancer: Many Treatment Options
This year in the United States, roughly 180,000 women with a new diagnosis
of breast cancer will face a myriad of choices about how to best treat their
For most, that will include some form of drug treatment after surgery or
surgery and radiation.
Prior to 2000, this often included five years of treatment with tamoxifen
for postmenopausal patients with tumors that respond to hormone treatments.
These days, however, a newer class of estrogen-targeting drugs, known as aromatase
inhibitors, is often recommended instead of tamoxifen for the treatment of
hormone-sensitive breast cancers.
The newly published study included only a small number of patients treated
with aromatase inhibitors, so the relevance of the findings for the majority of
patients being treated today are not clear.
But they have obvious relevance for the millions of breast cancer survivors
who did take tamoxifen -- usually for five years after initial treatment.
The study included 2,838 patients with stage I to III breast cancers treated
with chemotherapy, tamoxifen, or both after their initial treatment.
Five years after all treatment ended, the risk of relapse was 7% in women
treated for stage I disease, 11% in women treated for stage II disease, and 13%
in women treated for stage III disease.
Among breast cancer patients who were still free of cancer five years after
beginning drug treatment, 89% remained cancer-free five years after that and
80% remained cancer-free 10 years after ending treatment -- 15 years after
The study was made public Tuesday in the online issue of the Journal of
the National Cancer Institute.