Besides skin cancer, breast cancer is the most common cancer in women. About 1 in 8 women develop breast cancer.
The mammogram remains the most effective and readily available method for screening. According to the American Cancer Society, the mortality rate from breast cancer was slowly increasing until 1990, when death rates began to decrease.
The decline was caused by both advances in treatment and early detection. The early detection of breast cancer came from the introduction of mammography.
Digital mammography, a major advance, is now readily available.
The goal of a screening mammogram is to detect breast cancer at an early stage, while it is easily treated. High-quality mammography can detect cancers as small as 1 centimeter, about the width of a popsicle stick.
Mammography isn't a perfect test. It can miss up to 10-15 percent of breast cancers. This is a result of several factors.
The most important factor is the patient's own breast tissue. Dense breast tissue can make small cancers harder to see. In contrast to film mammography, digital mammography takes an electronic image of the breast and then stores that image in a computer. Digital mammography performs better in denser breasts because the tissue contrast can be manipulated.
Overlapping breast tissue can also complicate detection. Tomosynthesis, a technique that helps to eliminate the problem of overlapping breast tissue, is now approved for clinical use to supplement digital mammography. In tomosynthesis, the X-ray tube moves in an arc above the breast and obtains multiple images of the breast tissue. It requires compression of the breast, similar to a regular mammogram, and the radiation dose is comparable to that of a standard mammogram.
Breast ultrasound and breast MRI also can be used to supplement the mammogram in patients who have a high risk of developing breast cancer and or in those with dense breast tissue. Ultrasound and MRI test can detect cancer, but they aren't meant to replace mammography. There are certain types of cancers that are best seen on the mammogram.