Marrow Cells May Predict Breast Cancer Outcome

Traces of malignant cells in the bone marrow of newly diagnosed breast cancer patients are a significant indicator of a poor prognosis, researchers report.

They add that this "micrometastasis" could be used to monitor the extent of the cancer and also to evaluate the success of chemotherapy.

"The presence of tumor cells in the bone marrow of breast cancer patients is a poor sign for patients," said lead author Dr. Stephan Braun, a professor of obstetrics and gynecology at Innsbruck Medical University in Austria. In addition, using this marker will change the design of clinical trials, Braun said.

Their report appears in the Aug. 25 issue of the New England Journal of Medicine.

In their study, Braun and his colleagues collected data on more than 4,700 women with invasive breast cancer from nine other studies. They evaluated patient outcomes over a period of 10 years.

The researchers found micrometastasis in 30.6 percent of the patients. Women who had signs of cancer cells in their bone marrow had significantly poorer outcomes over the follow-up period compared with women who did not, Braun's team found. Outcomes were poorer in terms of both disease-free survival and overall mortality.

"The next step will be to design clinical trials to demonstrate that this marker is valuable," Braun said. "The marker is a way to see if the tumor has responded to chemotherapy, or if chemotherapy is needed."

Braun noted that right now 90 percent of breast cancer patients are given chemotherapy. But only 25 percent may actually need chemotherapy, since 75 percent are cured by surgery alone, he said.

"Actually, it's an over-treatment of at least 60 percent of the patients, given that we have identified, more or less by chance, those patients who need chemotherapy," Braun said.

Moreover, Braun believes that this marker may identify patients who need chemotherapy after surgery, and it also provides a way to see whether chemotherapy has been successful.

"This marker can be used to identify patients at risk and to see if tumor cells are cleared or not after chemotherapy," Braun said. "In addition, if the tumor cells are cleared after chemotherapy, we believe we have successfully treated patients."

One expert is skeptical of the value of using micrometastasis as a marker for deciding how to treat patients, however.

"Knowing that someone has a worse prognosis is valuable primarily if it results in a change of therapy to improve prognosis," said Dr. George W. Sledge, a professor of medicine, pathology and oncology at Indiana University. "Since we offer adjuvant therapy (chemotherapy or hormonal therapy) to most patients with tumors bigger than one centimeter, I'm not sure how this helps."

"The other potential means by which an indicator of bad prognosis might be of potential help would be if it eliminated certain patients from needing therapy," Sledge said.

"I'm not at all certain that this test accomplishes this either," he added.

By Steven Reinberg
HealthDay Reporter (8-24-2005)

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