Atlas of breast cancer early detection

Breast ultrasound uses sound waves to produce images of internal breast tissues. The high-frequency linear transducer sends sound waves through the breast tissues, and these echo back to form an image of the tissues.
Ultrasound is a safe, non-invasive procedure that does not use ionizing radiation. It is widely available and does not require extensive infrastructure.
Breast ultrasound is a very useful tool for the evaluation of women with breast symptoms or those referred after an abnormal screening test result. It is a useful adjunct to diagnostic mammography, especially for women with dense breast tissue. The role of breast ultrasound as a stand-alone test for breast cancer screening has not yet been established.

A Working Group of 29 independent experts from 16 countries, convened by IARC in November 2014, reviewed the scientific evidence and assessed the cancer-preventive and adverse effects of various methods of screening for breast cancer. Their assessments were published as IARC Handbooks of Cancer Prevention Volume 15: Breast Cancer Screening. The IARC Working Group concluded that the use of ultrasound as an adjunct to mammography in women with dense breasts and with negative results on mammography has some value. They found that there is:

• inadequate strength of evidence that screening with ultrasound reduces breast cancer mortality;
• inadequate strength of evidence that screening with ultrasound reduces the rate of interval cancer detection;
• limited evidence that screening with ultrasound increases the breast cancer detection rate; and
• sufficient evidence that screening with ultrasound increases the proportion of false-positive screening outcomes.

Significant recent advancements include automated whole-breast ultrasound (ABUS) and portable hand-held ultrasound machines for the examination of breasts.