Breast Cancer Cases

Mammography

Advances in screening mammography have led to earlier detection of breast cancer and improved chances of survival among women diagnosed. Results of an analysis of breast cancer screening trials found a 26% reduction in breast cancer mortality over 7-9 years among women screened at ages 50-74 years old.³ The American Cancer Society recommends that women who are 40 or older undergo yearly screening mammograms.

Screening mammography offers the advantage of identifying malignant masses before they become clinically detectable. This highlights the difference between screening and diagnostic mammograms. Screening mammography is an x-ray of the breast performed at regular intervals on women who have no signs or symptoms of cancer for the purpose of promoting early discovery of this disease. Diagnostic mammography is an x-ray of the breast performed on women who have a lump or other symptoms suspicious for breast cancer, or who have a possible abnormality detected on screening mammography. Other mammography techniques such as magnification views or breast compression studies offer the physician more detailed radiographic information as to areas of the breast which have been identified as needing further investigation.

Certain mammographic features such as clustered microcalcifications, increasing density or a new mass (not seen on prior mammograms), a mass with irregular or spiculated (spiked) borders, or certain asymmetries between the right and left breast are suggestive of malignancy, and require further imaging or biopsy. Comparison with earlier mammograms is essential to a thorough evaluation and assessment by the radiologist. This is why, whenever possible, a woman undergoing periodic screening mammography should return to the same imaging center every year, or at least bring her previous mammogram films with her if she is undergoing imaging at a new facility for the first time. Digitalized mammography is now available at some centers with computer assisted detection software. This software is designed to assist the radiologist in detecting worrisome areas.

In conjunction with other organizations, the American College of Radiologists has developed a uniform system for classifying and reporting the level of suspicion for breast cancer on mammography or ultrasound, and what action, if any, should be taken in follow-up. This system is known as the Breast Imaging Reporting and Data System (BIRADS). Under BIRADS, a score should be given indicating the radiologist’s opinion on the absence or likelihood of breast cancer. The BIRADS scores range from 0 to 6 and are classified as set forth below:

Category	Diagnosis	Number of Criteria
0	Incomplete	Your mammogram or ultrasound didn’t give the radiologist enough information to make a clear diagnosis; follow-up imaging is necessary
1	Negative	There is nothing to comment on; routine screening recommended
2	Benign	A definite benign finding; routine screening recommended
3	Probably Benign	Findings that have a high probability of being benign (>98%); six month short interval follow-up
4	Suspicious Abnormality	Not characteristic of breast cancer, but reasonable probability of being malignant (3 to 94%); biopsy should be considered
5	Highly Suspicious of Malignancy	Lesion that has a high probability of being malignant (>=95%); take appropriate action
6	Known Biopsy Proven Malignancy	Lesions known to be malignant that are being imaged prior to definitive treatment; assure that treatment is completed

Despite advances in imaging technology and development of reporting standards, delays still occur as a result of failing to report or underreporting worrisome findings, failing to recognize important changes by comparison with prior mammograms, failing to recommend or carry out additional needed imaging or biopsy, and communications break downs resulting in patients not being informed of abnormal results.

³Efficacy of screening mammography. A meta-analysis. JAMA 273: 1995; 149-154.

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