Mammography: Is It Still The Best Test for Breast Cancer?

Armen Hareyan's picture

Signs of Breast Cancer

Although breast cancer can occur in younger women, the chance of having breast cancer is not typically a significant problem until age 40 or so. The often-quoted, one-in-eight risk of having breast cancer is misleading as it applies to an entire population over a full lifetime. At age 40, a woman's risk of having breast cancer in the next 10 years is about one in 70, and for a 70-year-old woman, the 10-year risk is one in 25.

Although the risk is perhaps lower than the usually quoted number, it is still a potential problem. So, what should women do about it? Early detection remains the best bet for effective treatment. Along those lines there are several things to consider: breast self-exam and clinical breast exam by a trained medical person and mammography.

Breast self exam is certainly a reasonable thing to do. To be effective, it should be done thoroughly and regularly, typically monthly after the menstrual period is over when breasts are a bit less swollen and tender. One's physician or the doctor's nursing staff can provide training on self exam or go to for information.

If something suspicious is found, the next step is to see the doctor for a clinical breast exam. Physicians and other health-care providers should be able to better characterize the finding and help to decide if other diagnostic techniques should be used to further evaluate the breast.

Mammography remains the best test for breast cancer to date. Standard mammography uses conventional X-rays to look at the deep breast tissue for signs of breast cancer. Since the breast is a round structure, in order to get a clear picture, it must be flattened or the edges will be overexposed and the center underexposed giving an unreliable image. Some women may find this process of flattening the breast uncomfortable, so it's important to work with the X-ray technician to try to get the best image with the least discomfort.


Mammography is not perfect. A small, but significant portion of cancers can be missed. No matter how good the technique, small lesions can be obscured by dense breast tissue. The radiologist can increase the chance of finding small abnormalities by comparing one mammogram to previous ones to look for changes. That is why it is important to get mammograms at regular intervals, typically every one to three years in one's 40s and annually after age 50.

Traditional mammography is done with a photographic plate and the image is a film image. Digital imaging has been developed in an effort to improve the fine features of mammography. Studies suggest that in women with dense breasts where normal breast structure can obscure subtle abnormalities, digital mammography may detect cancers better than film mammograms. In addition, computer-aided reading of mammograms can enhance the radiologist's reading. MRI mammography has been added to the mix of detection aids and is particularly useful in women at high risk of breast cancer due to a family history or in young women whose breasts are difficult to image in the traditional ways.

The problem with digital mammography, computer-aided readings and MRI mammography is they are very sensitive but not significantly more specific. That means more abnormalities are found, but too many of the abnormalities are not cancer.

It is difficult to be exact in determining how many people will be helped by routine screening because there are so many details that can affect outcome if cancer if found: the stage at diagnosis, the availability and type of treatment, the skill of the treating physicians, the woman's own age and health at time of diagnosis, the type of cancer detected and so on. One estimate by the National Cancer Institute is for women between 50 and 70 years of age; for every 1,700 to 5,000 women screened annually for 15 years, one life will be extended.

What about older women? When can screening mammography stop? That depends on a woman's overall health and current life expectancy. A healthy, active woman of 85 could easily have 10 or more years of life. For her, it could be beneficial to detect breast cancer early. For others, medical problems may be more likely to cause death than breast cancer.

Statistics can be deceiving. The cold facts of how effective screening can be should not discourage women from screening for breast cancer. When it comes down to one patient, the decision is more complex. For that reason, every woman should discuss screening for breast cancer with her physician or other health-care provider to get a personal recommendation and help with understanding the results of her screening.

October is breast cancer awareness month. Being aware of the problem, women can review their personal medical information and family history and become educated in order to increase the chance of early detection and treatment should she have the misfortune of developing a breast cancer. Knowledge will help every woman to make better, informed choices about her personal health - information that could save her life.