Quantitative study of breast cancer progression: different pathways for various in situ cancers.

The chromatin pattern in nuclei from breast ductal proliferative lesions was quantitatively evaluated with the objective of deriving measures of tumor progression. A total of 110 cases were analyzed. There were 38 cases of normal tissue or benign proliferative lesions, 41 cases of ductal carcinoma in situ (DCIS), and 31 cases of microinfiltrating DCIS and of infiltrating cancer. A total of 9424 nuclei were analyzed. High-resolution images were digitally recorded. For each nucleus, 93 karyometric features descriptive of the spatial and statistical distribution of the nuclear chromatin were computed. Data analysis included establishing a profile of relative deviations of each feature from "normal," called the nuclear signature, and of lesion signatures as well as of trends of lesion progression. Two trends of evolution could be discerned: one from normal to hyperplasia, atypical hyperplasia, and comedo DCIS as representative of high-grade lesions; and the other from normal to hyperplasia to cribriform DCIS, solid DCIS, and infiltrating cancer, representing lower grade lesions. The nuclei in microinfiltrating foci are distinctly different from nuclei in high-grade comedo DCIS. The nuclei in microinfiltrating foci have a statistically significantly lower nuclear abnormality. They may represent outgrowing clones.

Quantitative study of ductal breast cancer progression: nuclear signatures for evaluation of progression grade.

The evaluation of progressive morphological changes, with 93 morphometric parameters in tissue lesions representative of ductal breast cancer progression, has been performed in order to define in great detail the profile of chromatin texture (nuclear signature) changes. A gradual, distinctive increase in nuclear signature alterations from hyperplasia to infiltrating carcinoma has been found. The nuclear signatures' analysis of microinfiltrating foci in comedo DCIS showed sharp differences compared with those of comedo DCIS they derived from: these foci consist of cells with smaller and also more homogeneous nuclei. Opposite to the prominent heterogeneity of those of comedo DCIS: they appear to express a reduced clonality in the new, more progressed, cell population. Digital analysis of chromatin patterns seems to be useful, beyond mere extraction of individual features of value, in getting objective data for individual grading and prognosis of breast cancer.

Differential expression of p57kip2, a maternally imprinted cdk inhibitor, in normal human placenta and gestational trophoblastic disease.

Evidence has recently been provided to support a role for genomic imprinting in the regulation of embryonic implantation and development and placental growth, as well as in the pathogenesis of proliferative trophoblastic diseases. The cyclin-dependent kinase inhibitor p57KIP2 has recently been recognized as a maternally imprinted gene. We investigated p57KIP2 expression in first-trimester normal placentas from interrupted pregnancy, spontaneous abortions, and different types of proliferative trophoblastic diseases using single- and double-marker immunohistochemical techniques. In normal placenta, nuclear p57KIP2 expression was observed at high frequency (up to 100%) in extravillous trophoblast, cytotrophoblast, and implantation-site interstitial trophoblast, but was absent in syncytiotrophoblast. p57KIP2 was also expressed in the stromal cells of maternal decidua, which was one of the few adult tissues retaining p57KIP2 expression (most other adult tissues investigated were negative). p57KIP2 expression was either absent or low in all cases of diploid/tetraploid complete moles (20 cases) and in three cases of gestational choriocarcinoma. On the other hand, all spontaneous abortions (12 cases) and triploid partial moles (19 cases) showed p57KIP2 levels comparable to those observed in normal placenta. These findings are in line with the hypothesis that deregulation of genomic imprinting, particularly the loss of cell-cycle inhibitors such as p57KIP2, is involved in the abnormal development of androgenetic trophoblastic proliferations. In addition, this simple immunohistochemical analysis could provide a useful diagnostic marker in difficult cases.