Pathology (Philadelphia, Pa.)最新文献

During the last few years considerable effort has been made to find genetic and biochemical markers that could be used to predict the behavior of cancers with greater accuracy than that obtained by histologic grading or the assessment of other established morphologic features. Because there is considerable evidence that malignant neoplasms have cytogenetic abnormalities, and because atypical features of the nucleus such as pleomorphism and hyperchromasia are known to be prognostically unfavorable findings, quantitative analysis of nuclear DNA was a prime candidate for evaluation. Also, the rate at which malignant tumor cells replicate, and the fraction of tumor cells participating in the proliferative process, are of considerable interest to oncologists for use in assessing patient prognosis and for guiding decisions on the use of various endocrine and cytotoxic agents for adjuvant endocrine and chemotherapy.

In the context of recent developments, the role of the surgical pathologist in evaluating and reporting breast cancer specimens has become more important. The pathologist must not only diagnose carcinoma in a given patient, but must also document a set of morphologic features that have been shown to be important in determining prognosis and guiding therapy.

At CPMC routine mammographic screening was introduced in late 1975. The total volume of breast cancers, other than outside consultations, seen in the department increased from 71 in 1975 to 164 by 1988, an increase of 230%. This expansion in volume was due largely to surgical removal of mammographically detected occult, in situ duct and relatively small invasive duct carcinomas. In 1974, prior to routine mammographic screening, in situ carcinomas represented only 4% of all breast cancers seen in the Department of Pathology at CPMC. However, after the introduction of mammographic screening, the proportion of in situ cancers increased steadily. By 1988, 45% of all breast cancers seen in our hospital were found by mammography. While data on the size distribution of invasive breast cancers are not available at our hospital prior to 1976, an appreciable effect of mammography is still evident when the numbers of relatively small invasive cancers detected in 1976 are compared with those detected in 1988. Invasive breast cancers 10 mm in diameter or less represented only 6% of all cancers in our series in 1976, but 33% in 1988. These findings confirm observations made by Gibbs on the pathology of breast cancers found in mammographically screened and unscreened populations. The detection of increasing numbers of relatively small invasive duct carcinomas produced an overall reduction in the average diameters of invasive cancers seen at CPMC. The average dropped from 30 mm in 1975 to a low of 14.8 mm in 1987. Mammography did not appear to be effective in the early detection of invasive lobular cancers and had no impact on reducing their size. The implications of early discovery of in situ duct and relatively small invasive duct carcinomas are for improved patient survival through: (1) preventing progression of in situ duct to invasive duct cancers, and (2) the removal of invasive duct cancers before reaching a size where there is a high risk of metastasis.

The capability of high-quality mammography to discover early, preclinical breast cancer has demanded the development of a new relationship between radiologists, surgeons, and pathologists. It is only through mutual understanding and appreciation of the technical requirements and interpretive difficulties involved in the successful identification, preoperative localization, and excision of these lesions that the full benefits of this method of early cancer detection can be brought to all of our patients.

Because of cost and manpower considerations, the approach to handling the mammographically directed biopsy in the author's hospital is a modification of the approach described in the previous article. The differences in approach are described.

Achieving the maximum yield of breast cancers detected by mammography has required certain changes in tissue handling and examination of the mammographically directed breast biopsy. This new radiographic technique, increased use of breast-conserving surgical approaches for the treatment of breast cancer, more enlightened and demanding patients, and increasing medical-legal exposure have all contributed to changes in the way surgical pathologists should process and sample breast biopsy specimens.

During the next few years pathologists can expect to be called upon with increasing frequency to extract data on a number of cell cycle, biochemical, and genetic features of breast cancers as a routine part of the specimen examination. Obtaining this information without compromising the histologic diagnosis or losing morphologic-based prognostic information is challenging, particularly with small invasive breast cancers, but is a service pathologists should be able to provide.