Dec. 12, 2002 (San Antonio, Texas) -- More frequent chemotherapy for breast cancer improves survival chances with few side effects, according to a landmark study presented at a meeting of specialists. Some experts are even calling for this to be the new standard of care.
Women who are given chemotherapy more frequently, called "dose-dense therapy," are 31% less likely to die, compared with those who undergo conventional treatment, the study by the National Cancer Institute's Breast Intergroup showed. And while there were worries that the new regimen would prove more toxic, that was not the case, the researchers said. The study was presented at the 25th Annual San Antonio Breast Cancer Symposium.
Based on the findings, some investigators said the new regimen should now be considered a standard for women with early breast cancer.
"Since breast cancer is so common, the new regimen could potentially save thousands of lives per year in the United States alone," says Larry Norton, MD, head of the division of solid tumor Oncology at Memorial Sloan-Kettering Cancer Center and senior researcher of the study.
The study enrolled nearly 2,000 women with first-time breast cancer that had spread to the lymph nodes but not to other parts of the body. After undergoing surgery to remove their tumors, they were assigned to one of four treatments. Some women received chemotherapy under the dose-dense regimen -- every two weeks -- while other received the standard chemotherapy treatment -- every three weeks.
Several years later, researchers found that women on the dose-dense regimen were significantly less likely to suffer a recurrence or die from their cancer.
Among women on the dose-dense regimen, 82% were free of breast cancer four years later, compared with 75% of those who received conventional therapy.
And 92% of women on the dose-dense treatment were alive three years later, compared with 90% of those on the conventionally administered regimens.
The benefits of the dose-dense regimen were expected to increase over time, says researcher Marc L. Citron, MD, clinical professor of medicine at Albert Einstein College of Medicine in New York.
The idea behind dose-dense dosing is simple: Giving the drugs more frequently doesn't give the cancer as much time to grow between treatments. Thus, each time you treat, you're treating a smaller and smaller amount of cancer.
But for years, doctors were reluctant to try the dose-dense regimen. The reason: Frequent chemotherapy can cause the number of white blood cells to decline -- a condition that increases the risk of serious infection.
But the development of drugs that increase the number of white blood cells in women undergoing chemotherapy has changed all that, the researchers said.
In fact, women on the dose-dense regimens were given such a drug and were less likely to develop a low white blood-cell count, the study showed.
Other side effects were equally common among women on both regimens.
"The bottom line is that the data suggest you can accomplish the same or better in terms of outcome by decreasing the interval between treatments," says William Gradishar, MD, associate professor of medicine at Northwestern University and another study researcher. "For patients with early breast cancer, this should be considered a standard of care."
Jeffrey Abrams, MD, who heads breast cancer trials at the National Cancer Institute, cautions that until the findings are confirmed in future studies, it is too soon to say whether a dose-dense chemotherapy regimen should be the new standard of care.
Nevertheless, he added, the reduced risk of recurrence and death, coupled with the low occurrence of side effects, are encouraging.