(HealthDay is the new name for HealthScoutNews.)
WEDNESDAY, July 2, 2003 (HealthDayNews) -- Two new studies seem to have reached vastly different conclusions on how to best treat aggressive, recurring breast cancer.
The first report, out of Northwestern University's Feinberg School of Medicine in Chicago, concludes that adding high-dose chemotherapy with bone-marrow transplantation to traditional chemotherapy offers little benefit to women suffering from breast cancer. Not only that, but several women on the high-dose regimen died of leukemia or other disorders.
The second study, out of the Netherlands, found exactly the opposite: high-dose chemotherapy and bone-marrow transplantation did improve relapse-free survival for certain patients.
Both findings appear in the July 3 issue of the New England Journal of Medicine.
A debate has long simmered over whether high-dose chemotherapy might improve the odds for women with aggressive, recurring breast cancer. Because the high-dose treatment destroys marrow, the procedure is accompanied by bone-marrow transplantation.
Both studies looked at women who had positive lymph nodes and who had undergone surgery to remove the primary tumor.
The Northwestern researchers randomly assigned 540 women to receive either six cycles of standard chemotherapy or standard chemotherapy followed by high-dose chemotherapy with bone-marrow transplantation. The women were enrolled between 1991 and 1998 and were followed for a median of just over six years.
After assessing 511 women, the authors found the six-year overall survival rate was 62 percent in the group that received standard chemotherapy alone and 58 percent in the group that received high-dose chemotherapy, a difference not considered statistically significant.
Also at six years, 48 percent of the patients in the standard group were free of recurrence versus 55 percent in the high-dose group -- again, not a significant difference.
But, 18 of the women getting the high-dose chemotherapy died.
The Dutch study looked at 885 women. All patients had five courses of a standard chemotherapy, followed by radiotherapy and tamoxifen, while one group also received high-dose chemotherapy with bone-marrow transplantation.
The five-year, relapse-free survival rates were 59 percent in the conventional group and 65 percent in the high-dose group. Among women with at least 10 positive lymph nodes, the recurrence-free survival rates were 51 percent in the conventional group and 61 percent in the high-dose group.
Just as the studies reach different conclusions, experts too are divided on their significance.
"When I look at the overall evidence [from these and other studies], I don't think high-dose chemotherapy is an accepted standard regimen," says Dr. Jeffrey Abrams, associate chief of the clinical investigations branch at the National Cancer Institute. "It may still be an area of investigation" for the future, he adds, "but with that said, I don't think it should be part of standard treatment."
However, Dr. George Somlo, associate director of high-dose chemotherapy in the division of medical oncology and therapeutics research at City of Hope National Medical Center, understandably has a different perspective.
"The study from the Netherlands is the one I would consider more meaningful," he says. "The Dutch study to me is a better study in terms of design and credibility. Clearly they found that in those with 10 or more lymph nodes -- high-risk characteristics -- there was a definite advantage, in my mind."
"Both studies show no difference in overall survival between those that got high dose and those got conventional chemotherapy, so the only thing they show is that there may be a decrease in relapse rates in those who got the high dose," says Dr. Avi Barbasch, an associate clinical professor of medical oncology at the Mount Sinai School of Medicine in New York City. "It took a little bit longer for the disease to come back."
Another question is whether high-dose chemotherapy with bone-marrow transplantation has been supplanted by other therapies in the years since these studies were begun.
"For people who have 10 or more nodes, I think the treatment today would be quite different," Barbasch says. Growth factors stimulate the body to make white blood cells. "One of the things that's getting a lot more play is doing it more frequently, dosing weekly or every two weeks with growth-factor support in between so the patient can withstand more intensive treatment," he adds.
"People were hoping that given how toxic the [high-dose chemotherapy] treatment was that we would see a rather major effect, and the effect that we're seeing is not different than the types of improvements that we've seen by the simple addition of a new drug like Taxol to standard regimens, or a recent study that gave the standard treatment every two weeks instead of every three weeks," Abrams says. "Improvements are in the range of 5 to 10 percent, but those kinds of improvements haven't necessitated these high doses, which are extremely expensive and have severe side effects."
More information
For more on high-dose chemotherapy, visit the National Cancer Institute or the American Cancer Society.
