Circulating Tumor Cells: Will They Be Clinically Useful?

Abstract

versus 10.1 months) and progression-free survival (7.0 versus 2.7 months) than those with fi ve or more CTCs per 7.5 mL of blood. Three to 4 weeks later, after therapy, the difference between the groups remained statistically signifi cant. And after therapy, the number of women in the lower-level CTC group increased, presumably because of a positive response. In a follow-up study with the same patients, published in Clinical Cancer Research in 2006, G. Thomas Budd, M.D. , professor of medicine at the Cleveland Clinic in Ohio, reported that the number of CTCs in this population was a better indicator of disease progression than traditional imaging techniques such as computed tomography and magnetic resonance imaging; CTCs were more reproducible, were better predictors of survival, and estimated disease progression earlier. A 2009 Annals of Oncology article reported that CTC levels were a good predictor of overall survival in metastatic breast cancer patients. Colon cancer patients have shown similar results. Neal Meropol, M.D., from University Hospitals Case Medical Center in Cleveland, was part of a team that tested whether CTCs were associated with prognosis in patients with metastatic colorectal cancer. Among the 430 patients who took part in this study, there was a statistically signifi cant difference associated with CTC levels. Circulating Tumor Cells: Will They Be Clinically Useful?