High DNA content and prognosis in lymph node positive breast cancer. A case control study by the University of Leiden and ECOG. (Eastern Cooperative Oncology Group)

Hormonal influences on cancer progression and prognosis

Cell differentiation, proliferation, apoptosis, and cell motility are induced and regulated by a host of growth factors, vitamins, and hormones. The mode of function of these modifiers of biological response, the signaling pathways that they activate, and the interacting pathways that can influence the biological outcome have been the focus of attention. Especially recognized and discussed in this review is the deregulation of their function, leading to abnormalities in cell proliferation, alteration of intercellular adhesive cohesion, remodeling of the extracellular matrix, and invasive behavior and metastatic deposition that are so characteristic of tumor development and progression, which strongly underscores the concept of molecular progression of cancer constructed on the basis of the relationship between genetic changes and the biological events associated with cancer progression. The molecular changes associated with hormone- and vitamin-driven responses and the deregulation of the expression and function of their target genes seem to correlate with specific biological events linked with cancer invasion and progression, and these findings could lead to the establishment of new markers of progression and to the development of new strategies for patient management. The scope of this work has been restricted by design and is dictated by the field of interest of the author's laboratory, but it is hoped that this field would be regarded adequately to reflect the wide genre of scientific interest in this field of human disease.

The S-phase fraction of the aneuploid cell subpopulation is the biologically relevant one in aneuploid breast cancers

BACKGROUND

In the case of DNA-aneuploid tumors there are no clear guidelines as to which S-phase fraction is the more relevant one: that corresponding to either the diploid or the aneuploid population, or rather an average of both.

MATERIALS AND METHODS

We studied 280 breast cancer specimens from previously untreated patients. Histologically, 231 were ductal infiltrating carcinomas, 30 lobular infiltrating carcinomas and 19 corresponded to other, less frequent varieties. Postsurgically, 164 cases (58.6%) were classified as T1, 87 (31.1%) as T2 and 7 as T3. The remaining 22 cases were multifocal, diffuse tumors. Flow cytometry was performed on fresh tumor tissue, and immunohistochemistry for hormone receptors, Ki67, c-erb-B2 and p53 on paraffin-embedded material.

RESULTS

In diploid tumors, a high S-phase (above the 75th percentile) correlated significantly with Ki67 expression > or =20% (p<0.0001). In aneuploid tumors, however, this was only the case for the aneuploid fraction of tumor cells (p< 0.0001). A high S-phase of diploid tumors correlated directly and significantly with a high histologic grade (p=0.04), a high nuclear grade (p=0.01), tumor size (p=0.0008), and inversely with estrogen (p<0.0001) and progesterone (p<0.0001) receptor expression. In aneuploid tumors, the aneuploid tumor fraction showed a direct and significant correlation with a high histologic grade (p=0.005), a high nuclear grade (p=0.001), mutant p53 expression (p=0.0009), and inversely with estrogen (p<0.0001) and progesterone (p=0.0001) receptor expression. A high S-phase of the diploid cell fraction of aneuploid tumors, on the other hand, just showed an inverse correlation with high nuclear grade of the tumors (p=0.02), and none whatsoever with all other tested parameters.

Proliferative activity in primary breast carcinomas is a salient prognostic factor

BACKGROUND

The goal of the current study was to investigate the prognostic impact of proliferative activity, together with the other classic clinicopathologic prognostic factors (tumor size, tumor grade, receptor status, ploidy, and lymph node status), in breast carcinoma by counting mitoses and evaluating S phase fraction (SPF) in fresh and frozen tumor samples.

METHODS

From March 1, 1990, to July 1, 1999, a total of 1984 previously untreated invasive breast carcinoma samples were snap-frozen for flow cytometry.

RESULTS

After multivariate analysis incorporating all classic prognostic factors, SPF combined with mitotic activity (i.e., proliferative activity) remained the sole prognostic factor in the lymph node-negative group; proliferative activity was accompanied by tumor size as a prognostic factor in patients with lymph node-positive disease and by lymph node status, lymphatic invasion, and receptor status in the overall population. The predictive value of proliferative activity was superior to that of the reference standards (classic prognostic predictors according to the guidelines of our institution [common oncology practice] and the St. Gallen classification). A review of the literature, focusing on series in which fresh material was used, allowed us to demonstrate that there is widespread agreement regarding the correlation between SPF and prognosis, even after multivariate analysis.

CONCLUSIONS

S phase fraction is a valuable predictor of survival and can confidently be assessed in approximately 80% of cases. In conjunction with mitotic activity, SPF should become a prognostic factor that is used in daily practice by oncologists for the management of breast carcinoma.

DNA ploidy and cell cycle distribution of breast cancer aspirate cells measured by image cytometry and analyzed by artificial neural networks for their prognostic significance

Chromosomal abnormalities are commonly associated with cancer, and their importance in the pathogenesis of the disease has been well recognized. Also recognized in recent years is the possibility that, together with chromosomal abnormalities, DNA ploidy of breast cancer aspirate cells, measured by image cytometric techniques, may correlate with prognosis of the disease. Here, we have examined the use of an artificial neural network to predict: 1) subclinical metastatic disease in the regional lymph nodes and 2) histological assessment, through the analysis of data obtained by image cytometric techniques of fine needle aspirates of breast tumors. The cellular features considered were: 1) DNA ploidy measured in terms of nuclear DNA content as well as by cell cycle distribution; 2) size of the S-phase fraction; and 3) nuclear pleomorphism. A further objective of the study was to analyze individual markers in terms of impact significance on predicting outcome in both cases. DNA ploidy, indicated by cell cycle distribution, was found markedly to influence the prediction of nodal spread of breast cancer, and nuclear pleomorphism to a lesser degree. Furthermore, a comparison between histological assessment and artificial neural network prediction shows a closer correlation between the neural approach and the development of further metastases as indicated in subsequent follow-up, than does histological assessment. These data demonstrate that artificial neural networks are capable of providing powerful and reliable indicators of possible lymph node metastasis, using measurements of cellular features alone.

FISH detection of HER-2/neu oncogene amplification in early onset breast cancer

HER-2/neu (c-erbB-2) gene amplification based on Southern blotting or immunohistochemistry has been shown to be predictive of poor outcome in breast cancer occurring in women over 40, but there is little data on the role of HER-2/neu in young women with breast cancer, many of whom may have inherited BRCA1 or other predisposing genes. The present study used fluorescent in situ hybridization (FISH) on archival specimens of breast cancer from 37 women under the age of 40 to evaluate the role of HER-2/neu amplification in this cohort, and to also evaluate the efficacy of FISH for quantifying amplification. The frequency of primary tumors with a greater than fourfold increase in gene copy number was found to be 38%, which is similar to the frequency of amplification reported in Southern blot studies in older women. However, the greater sensitivity of FISH enabled detection of low level amplification (more than 2 but less than 8 gene copies), which was found in an additional 30% of the tumors. Patients with low level amplification demonstrated a 54% recurrence rate, compared to 86% in those with high amplification and 17% in those with no amplification. HER-2/neu amplification appeared to be more prognostic of recurrence than nodal status, with 45% of node negative tumors recurring compared to 62% of those which were node positive, nor was tumor size predictive of recurrence in this cohort since tumors of 2 cm or less recurred in 44% of cases compared to 57% of those larger than 2 cm. Thus, this study demonstrates that FISH is a reproducible and sensitive technique for detecting HER-2/neu amplification, and that amplification of the oncogene is the strongest independent indicator of recurrence of breast cancer in young women.