Evidence is mounting that circulating tumor cells in the bloodstream, also known as CTCs, are a viable cancer biomarker tool. A team in Germany produced new evidence that their presence, or absence, may be an effective way to measure the survival chance of patients with early breast cancer.
Researchers at the Department of Gynecology and Obstetrics, Klinikum Innenstadt, Ludwig-Maximilians-Universitaet Muenchen, in Munich, Germany, and colleagues came to that conclusion through their look at blood samples from thousands of patients. The Journal of the National Cancer Institute published their study on May 15.
According to the research team, patients found to have CTCs in their bloodstream both before and after treatment had the worst disease-free survival rates compared to patients who lacked CTCs before and after treatment. That dubious achievement also stood in comparison with patients who had the CTCs before treatment but were free of the cells after chemotherapy, and patients who didn't have CTCs before treatment started but had them in their blood after the fact.
Put differently, a patient had a much lower chance of being free of cancer at 36 months if found to have CTCs in their blood; prognosis for survival became worse along with higher CTC levels. For patients who died during research follow-up, nearly 41% were found to have CTCs in their blood. Only 20.8% of patients who survived to the follow-up had CTCs in their blood samples, the research team said. Those numbers came from samples from 2,026 patients taken after their initial breast cancer surgery and before chemotherapy treatment. Scientists evaluated samples from 1,492 patients after their chemotherapy treatments.
While the sample size is pretty large, further studies would help buttress the initial findings. If this can be accomplished, CTCs could be a powerful biomarker tool to help evaluate early breast cancer patients and their prognosis after treatment, adding another personalized weapon against the disease. It would also be far less invasive than the current alternative--evaluating tumor cells in bone marrow, which requires a painful and invasive biopsy.
The German team's work adds to a growing effort to explore the viability of CTCs as biomarkers for other cancers. Earlier this year, for example, researchers at the University of Southern California Norris Comprehensive Cancer Center determined that the use of a circulating tumor cell blood test instead of the standard PSA biomarker diagnostic may be a better way to predict a patient's odds of surviving prostate cancer, with higher CTC levels post-chemotherapy pointing to a higher risk of death. San Diego's Epic Sciences recently allied with LabCorp ($LH) to give European drug developers access to its CTC testing tech as they develop treatments for a variety of cancers. Researchers in California and Texas are also pursuing CTC blood tests as a way to track prostate and breast cancers and help predict patient outcomes.
- read the release
- here's the journal abstract