Simple test may help predict breast cancer return
BARCELONA (Reuters) - A simple test to measure tumor cells circulating in the blood could make it easier to tell which breast cancer patients are at greatest risk of their cancer returning after treatment, a German researcher said on Monday.
Detecting these cells might also help doctors tailor chemotherapy treatments to make them more effective and reduce healthcare costs along the way, Julia Jueckstock, a gynecologist at the University of Munich, told the European Cancer Conference.
The study is important because it is one of the largest of its kind to investigate whether measuring such tumor cells can help predict the chances of cancer returning, she said.
Researchers have known about these cells for about 20 years and are now exploring the role they may play in cancer and studying ways to measure them. The cells themselves are considered dormant and are not believed to be harmful until they leave the bloodstream and settle on an organ, Jueckstock said.
"We think the level of circulating tumor cells will predict the recurrence in cancer," she said. "In low risk patients, you could use less aggressive treatments."
Breast cancer is the second most common cancer killer of women, after lung cancer. It will be diagnosed in 1.2 million people globally this year and will kill 500,000.
The German team has so far analyzed blood samples taken from 1,767 breast cancer patients at diagnosis and during chemotherapy and compared the results to those obtained from 852 of the same patients when they finished their treatment.
The results show that of the patients who initially tested positive for circulating tumor cells (CTCs), 10 percent tested positive for them after chemotherapy. Of those who were initially negative, 93 percent remained negative after treatment.
"We think the persistence of CTCs after chemotherapy treatment is likely to be predictive of the likelihood of recurrence of cancer in these patients," Jueckstock said.
Researchers have also used bone marrow to detect circulating tumor cells but that technique is more difficult to use so it is not performed widely. It can also be painful for the patient, Jueckstock said.
A simple blood screen could mean that patients who need extra chemotherapy will get it, while those who do not will not have to endure weeks or months of extra treatments, she said.
"We think we will have final results in the next five years," she said. "If they are as we expect, there could be an improvement in breast cancer treatments."
What breastcancer.org says about this article…
Simple test may help predict breast cancer return
If you've been diagnosed with early breast cancer, a lot of your treatment plan is aimed at reducing the risk of the cancer coming back (recurrence). Chemotherapy, targeted therapy, radiation therapy, and hormonal therapy given before or after surgery are all used to lower your risk of recurrence.
Better ways to determine the risk of recurrence would allow doctors to create treatment plans tailored to each woman's individual recurrence risk. So if there were a test that told you and your doctor that your recurrence risk was very low, you might decide to skip chemotherapy after surgery. Right now, some breast cancer characteristics -- such as grade and stage -- offer a rough estimate of your recurrence risk, but it's not as precise as anyone would like.
The study reviewed here offers hope that doctors eventually may be able to estimate anyone's risk of recurrence with more precision, allowing treatment to be tailored to individual risk. The researchers suspect that if circulating tumor cells (CTCs) are in the blood before and after chemotherapy given after surgery, the risk of recurrence is high. If CTCs are not in the blood before and after chemotherapy, the risk of recurrence is low. Still, this study doesn't prove that a CTC test would offer a more accurate estimate of recurrence risk.
There are two tests available that look at the genetic make-up of the breast cancer and use that information to predict recurrence. Those tests are the Oncotype DX and the MammaPrint. The Oncotype DX test is used to develop recurrence scores for lymph node-negative, estrogen-receptor-positive, early breast cancers. The MammaPrint test is used to develop recurrence scores for lymph node-negative, early breast cancers. Both of these tests are relatively new and have been tested on relatively small groups of women. Both tests cost more than $3,000.
Each woman's breast cancer situation is different. In addition to cancer characteristics, recurrence tests may give you and your doctor one more piece of information that you can use to make treatment decisions. If you've been diagnosed with node-negative, early breast cancer, talk to your doctor to see if a recurrence test makes sense for you. And stay tuned to breastcancer.org for the latest updates on new tests that will help ensure the best treatment for YOU.
