Ultrasound and resonance imaging scans can aid better breast cancer screening, reveals US study.
The research, published in the April 4 edition of the Journal of the American Medical Association, found that those two technologies helped spot small cancers that mammograms had missed.
The study followed 2,662 women at high risk for breast cancer, particularly because of dense breasts and/or a family history of the disease. They agreed to undergo three independent screenings in one year, arranged in random order.
The three tests found a total of 111 cancers, for about 2.6 percent of the total group.
Mammography, which is a low-energy X-ray of the breast, found 59 cancers, or 53 percent of the total cancers found.
Ultrasound, a scan that uses sound waves to produce a picture of the body's internal workings and is often used for pregnant women, found 29 percent of cancers on its own.
MRI scans which use a magnetic field combined with pulses of radio wave energy, found a total of eight percent of cancers that the other two methods had failed to detect.
Eleven cancers, or 10 percent, were not found by any of the three screening technologies, said the study.
"Annual ultrasound screening may detect small, node-negative breast cancers that are not seen on mammography," said the study.
"Magnetic resonance imaging may reveal additional breast cancers missed by both mammography and ultrasound screening," it said, adding however that MRI is not suitable for all patients and can carry higher costs and risks than other methods.
According to Kristin Byrne, chief of breast imaging at Lenox Hill Hospital in New York, the study shows that alternative testing methods can help spot cancers that mammograms miss.
"Nearly half of the cancers would not have been detected with mammography alone," said Byrne, who was not involved with the study.
"Breast cancer is difficult to detect on mammography in patients with dense breast tissue. Ultrasound and MRI detect a significant number of breast cancers which are not seen on mammography in patients with dense breast tissue," she added.
"Additional yearly screening with MRI and ultrasound is important in high risk patients with dense breasts for early detection."