TUESDAY, May 16, 2006 (HealthDay News) -- Typically, women diagnosed with advanced breast cancer that has spread to other parts of the body are offered chemotherapy or hormone treatment rather than surgery.
That's because many doctors believe surgery offers no survival advantage for patients with metastatic disease, and may even worsen outcomes.
But a Swiss study published in the May 15 online issue of the Journal of Clinical Oncology refutes that conventional wisdom.
Women with metastatic cancers who had their primary breast tumor removed and showed negative surgical margins -- indicating the surgeon had removed all the cancer -- were 40 percent more likely to be alive five years after their diagnosis than women who did not undergo the procedure.
Women whose cancer had spread to the bone were 80 percent more likely to survive five years than those who had no surgery.
"These findings will be a surprise for many clinicians, as almost all national and international guidelines on the treatment of metastatic breast cancer either do not include surgery of the primary tumor, or even recommend against it," said study author Dr. Elisabetta Rapiti, senior researcher at the Geneva Cancer Registry at the University of Geneva.
"Many clinicians, in fact, believe that in such cases, surgery of the primary tumor can accelerate progression of the metastases," she said.
In the study, Rapiti and her colleagues used the Geneva Cancer Registry to give them detailed information on cancer cases reported in the city of Geneva. The scientists analyzed nearly 5,000 cases of invasive breast cancer diagnosed since 1970, and selected 300 patients diagnosed with metastatic disease.
They found that more than half of the women, 58 percent, got no surgery for their primary breast cancer. The remaining 42 percent underwent either mastectomy or a lesser surgery to remove the tumor.
When the researchers analyzed the results, they found women who underwent the surgery and had negative surgical margins were 40 percent more likely to be alive five years after their diagnosis than women who had no surgery.
Put another way, 27 percent of women who had surgery with negative margins were likely to still be alive five years after the operation, the researchers found. Women who had surgery but positive margins had a 16 percent five-year survival rate. Those who did not have surgery had a 12 percent five-year survival rate.
"This is the first study to find such a marked improvement in survival at five years in women with metastatic breast cancer who have had surgical removal of the primary tumor," Rapiti said. Another study, published in Surgery in 2002, found similar effects, but only followed the women for three years.
Women whose cancer had spread to the bone (rather than the brain or the liver, other common sites) were even more likely to be alive five years later -- 80 percent more likely than those who did not have surgery.
According to Rapiti, the study results suggest more research needs to be done to assess the impact of surgery on women whose beast cancer has spread. Her team is hoping to study such women, comparing those who have surgery with those who do not, in a larger study.
For women, she said, "this research already certainly reaffirms that such treatment is not associated with a more rapid progression of the metastases or worse outcome."
The new study is food for thought but isn't yet a reason to change standard treatment, said Dr. Lori J. Goldstein, director of the breast evaluation center and leader of the breast cancer research program at Fox Chase Cancer Center in Philadelphia.
While the study does have merit, she said, it was a retrospective study, not a prospective one that would track people over time.
"Retrospective studies are very useful in generating hypotheses," she said. What's needed, she said, are prospective studies, such as a randomized controlled clinical trial. In such a trial, some women would be assigned to a surgery group and others to a treatment group, and then the results would be compared over time.
Too many factors come into play when assessing the risks and benefits of surgery, Goldstein said. "It would be naive to assume surgery will benefit all women with metastatic disease," she said.
More information
To learn more about breast cancer, visit the American Cancer Society.
