The natural history of mammographic calcifications subjected to interval follow-up

Chronological Changes of Microcalcifications of Breast Carcinoma

BACKGROUND: Clustered microcalcifications are important for the detection of breast carcinomas, but few reports have described chronological changes of the microcalcifications. METHODS: The mammographic features of 18 breast cancer cases for which previous survey films were available and in which clustered microcalcifications with no tumor shadows were recognized at diagnosis were studied. Chronological changeswere analyzed by measuring the increase in the length of areas containing calcifications and the diameters of microcalcifications on mammograms using computerized image analysis. RESULTS: Chronological changes in the length of areas of microcalcifications were classified into two types by simple linear regression. Fast increase was common in the comedo type of carcinoma and slow increase was common in the non-comedo type. Three of nine cases that received follow-up examinations on two or more occasions eventually changed from slow type to fast type, and the distributionpattern of diameters of microcalcifications also changed from non-comedo type to comedo type. A follow-up study of 48 cases with a cluster of fewer than five extremely fine calcifications revealed breast carcinoma in 7 patients within 5 years. CONCLUSION: The increase of microcalcifications was generally fast in comedotype and slow in non-comedo type lesions. An increase in the extent of microcalcification was seen occasionally during the last period between follow-up examinations in mixed type tumors, indicating a conversion of the intraductal component to a more malignant grade.

Computerized Image Analysis of Clustered Microcalcifications on Mammography: Morphome- tric Comparison between Mammography and Pathology

The clusters of microcalcifications under 2 cm in greatest dimension were analyzed in terms of size and shape by an image processor with a computer after being magnified 33 times. The mean diameter of mammographic microcalcifications was 188 µ m in benign cases, 226µ m in cribriform or papillary type cancer cases, 213 µ m in intermediate type cancer cases, and 324µ m in comedo type cancer cases, showing significant differences among the groups. The size distribution of mammographic microcalcifications in the comedo type was characteristic, showing a second peak in distribution between 500 and 700µ m. The radiodensity of microcalcifications compared to the breast parenchyma, the caliber of breast ducts containing the malignant calcifications, and the unit volume of calcium deposits within the ductal lumens were greater in cancer cases. The size and shape of mammographic microcalcifications were considered to be related to a combination of the caliber of breast ducts, unit volume of calcium deposits within the ductal lumens, and the density of breast ducts containing calcium deposits. Duct calibers were generally larger in cases of cancer lesions than cases of benign lesions such as duct papillomatosis, thus calcium deposits and microcalcifications were greater in the cancer lesion. Uneven distrubution of size and form of microcalcifications over 250 µ m in size, and increased radiodensity of calcifications were useful parameters for differential diagnosis rather than the density of calcifications.

Immediate biopsy versus observation for abnormal findings on mammograms: an analysis of potential outcomes and costs

BACKGROUND

The increased usage of screening mammography has led to an increase in the number of needle localized breast biopsies. The perceived low yield of the biopsies has caused concern about the costs and effectiveness of this procedure. Arguments have centered on what is the appropriate true-positive rate for screening mammography, and which abnormal findings may be observed rather than tested immediately.

METHODS

A decision analysis was done to help answer these questions. Factors evaluated included age of patient at discovery of abnormal finding, the rate of follow-up mammograms eventually requiring biopsy, the potential effects of tumor-doubling time on increasing the stage of disease, quality-of-life issues, and costs.

RESULTS

For an average 50-year-old woman the quality-adjusted life expectancy (QALE) was longer for immediate biopsy by 0 to 3 years, depending on the assumptions on tumor-doubling time; however, immediate biopsy increased the cost per patient from $700 to $900. The QALE was also superior for immediate biopsy if more than 30% of follow-up mammograms required biopsy, and immediate biopsy was more cost effective if more than 36% of follow-up mammograms required biopsy. Patient age did not affect the superiority of immediate biopsy over observation, although quality-of-life issues did.

CONCLUSIONS

Those lesions with a greater than 20% to 30% probability of being malignant, or lesions with potentially short doubling times, should undergo immediate biopsy. Lesions judged to be at lower risk may be observed for 6 months. Either of these recommendations should be adjusted depending on an individual patient's quality-of-life concerns.

The abnormal mammogram radiographic findings, diagnostic options, pathology, and stage of cancer diagnosis

An abnormal mammogram often will detect a mass, a cluster of calcifications, or both; these findings are not pathognomonic and require a tissue diagnosis to confirm the presence of invasive cancer, in situ cancer, or a nonmalignant process. Although mammography is very sensitive, its abnormalities may be nonspecific. Ultrasound may help to distinguish a cystic mass from a solid mass. The mammographic report should be concise and not vague and must provide the referring physician with clear information as to whether the test is normal, a biopsy must be performed on the abnormality, or the abnormality will be reviewed with a repeat X-ray examination in 6-month intervals until the nature of the abnormality is determined. A common error is to palpate a breast mass that is not visible on the mammogram (false negative) and assume that the mass is not cancerous. Reasonable interpretation of a mammographic abnormality must differentiate malignant disease from a variety of benign conditions and at the same time minimize the number of biopsies performed on a mammographic abnormality that proves to be benign. Asymptomatic breast cancer may be detected mammographically when screening mammography is used; five to seven cancers should be detected in each 1000 women when initially screened, and this incidence will decrease to 0.8-3.5 cancers per 1000 women screened, depending on their age. In recent reports, the detection of an in situ, or a Stage 0, breast cancer occurred in about 25% of the women screened. The earlier the stage, the better the prognosis and the more conservative the treatment options that may be offered to the patient. Every mammographic practice must be audited for quality control. Modern computer technology may make this effort less tedious and time-consuming than it was in the past.