Dr. Scher Discusses Circulating Tumor Cells

Howard I. Scher, MD, chief of the Genitourinary Oncology Service at the Sidney Kimmel Center for Urologic and Prostate Cancers at Memorial Sloan-Kettering, lead author of the COU-AA-301 trial that investigated circulating tumor cells (CTC), discusses the CTC blood test that is used to assess prognosis of patients with metastatic cancer.

Dr. Scher says that with any test a physician orders, they should first ask themselves why they are ordering the test. From patients with breast cancer, colorectal cancer and prostate cancer, Dr. Scher and colleagues have learned that if there is a large number of circulating tumor cells in the blood, the prognosis of that patient is worse than if the cells are not present or low. The CTC blood test can immediately inform a physician of a patient's prognosis. Clinical trial data shows that if CTC numbers are decreased with treatment, the patient will have a better prognosis than those whose counts do not decrease.