National Cancer Institute NCI Cancer Bulletin: A Trusted Source for Cancer Research News
October 2, 2012 • Volume 9 / Number 19

FDA Update

FDA Approves Ultrasound Imaging System for Dense Breast Tissue

The Food and Drug Administration (FDA) recently approved the first ultrasound device for use with standard mammography in women with dense breast tissue: the somo-v Automated Breast Ultrasound System (ABUS).

The somo-v ABUS will be available for women who have no symptoms of breast cancer, have had a mammogram that did not detect cancer, and have not had a procedure that could alter the breast's appearance in an ultrasound image, such as surgery or biopsy.

Dense breasts have a high amount of connective and glandular tissue compared with less-dense breasts, which have more fatty tissue. An estimated 40 percent of women undergoing screening mammography have dense breasts. These women have a higher risk of developing breast cancer, and, when cancer is detected, it is often at a more advanced stage and more difficult to treat than cancers found at a less advanced stage.

Mammograms of dense breasts can be difficult to interpret because connective and glandular tissue—as well as most tumors—appear as white areas on mammograms. As a result, dense breast tissue may obscure small tumors, potentially delaying the detection of breast cancer. 

The somo-v ABUS directs high-frequency sound waves at the breast, and multiple images of the entire breast are captured for review in about 1 minute. The system’s software generates three-dimensional images of breast tissue for evaluation.  

The FDA based its approval, in part, on a clinical study in which board-certified radiologists reviewed mammograms alone or with somo-v ABUS images for 200 women with dense breasts who had mammograms that appeared to be free of cancer. Biopsies were performed on masses detected with the somo-v ABUS to determine whether they were cancerous. The results showed a statistically significant increase in breast cancer detection when ABUS images were reviewed together with mammograms, compared to mammograms alone.

As part of the approval, the FDA is requiring the manufacturer to train physicians and technicians to use ABUS and to provide a manual that clearly defines quality-control measures.

New Treatment for Advanced Colorectal Cancer Approved

The Food and Drug Administration (FDA) has approved the drug regorafenib (Stivarga) to treat patients with colorectal cancer that has progressed after treatment and spread to other parts of the body. Regorafenib blocks several enzymes that promote cancer cell growth.

The safety and effectiveness of regorafenib were evaluated in a single clinical study of 760 patients with previously treated metastatic colorectal cancer. Patients treated with regorafenib plus best supportive care (BSC) lived a median of 6.4 months, whereas patients treated with placebo plus BSC lived a median of 5 months. In addition, patients treated with regorafenib experienced a delay in tumor growth (progression-free survival) for a median of 2 months compared with a median of 1.7 months in patients in the placebo group.

Regorafenib is being approved with a boxed warning alerting patients and health care professionals that severe and fatal liver toxicity occurred in some patients treated with the drug during clinical studies. The most common side effects include weakness or fatigue, loss of appetite, hand-foot syndrome, diarrhea, mouth sores, weight loss, infection, high blood pressure, and changes in voice volume or quality.

The drug was reviewed under the FDA’s priority review program, which provides an expedited 6-month review for drugs that offer major advances in treatment or that provide treatment when no adequate therapy exists.