The Limitations of Radiology in Metastatic Breast Cancer

Minetta Liu, MD, breast cancer specialist, Mayo Clinic, Rochester, Minnesota, discusses the limitations of radiology in the treatment of patients with metastatic breast cancer.

Liu says that the key in metastatic breast cancer is trying to stay ahead and determine the right time to change therapy. Currently, the gold standard for measuring this is by using imaging, such as CAT scans, MRIs, and ultrasounds.

However, Liu says, it is difficult for a radiologist to measure these tumors in a reproducibleway. A study in several solid tumors found a variability of 15% when separate radiologists were asked to look at identical images. Surprisingly, Liu says, the variation was even higher when the same radiologist looked at the same picture just one week later.

Liu says that a better, more reliable method must be determined. Counting circulating tumorcells (CTCs) are more reliable and reproducible and the variation is only on the order of 1% to 5%.

Although no test is perfect, having multiple, reliable tools would help physicians to measure the progression of metastatic breast cancer, Liu says.

Clinical Pearls

• The key in metastatic breast cancer is trying to stay ahead and determine the right time to change therapy
• It is difficult for a radiologist to measure these tumors in a reproducible way
• Counting circulating tumor cells (CTCs) are more reliable and reproducible
• Having multiple, reliable tools would help physicians to measure the progression of metastatic breast cancer