Identification of a low-risk group of stage I breast cancer patients by cytometrically assessed DNA and nuclear texture parameters

The prognostic significance of determining DNA content in breast cancer by DNA image cytometry: the role of high grade aneuploidy in node negative breast cancer

AIM

To investigate the role of DNA aneuploidy, particularly in patients with node negative breast cancer, in order to identify the different risk profiles within the pool of heterogeneous breast cancers.

METHODS

Imprint smears from 370 breast carcinomas were Feulgen-stained and measured by DNA image analysis. DNA aneuploidy was graded by the amount of aneuploid cells (DNA content >5c) and highly aneuploid cells (DNA content >9c) in a breast tumour population. These results were correlated to the clinical long-term follow-up. A statistical cut-off value of >10 aneuploid cells (>5c) and of >1 highly aneuploid cell (>9c) was evaluated as significant for disease-free survival (DFS) and overall survival (OS).

RESULTS

Subgroups among patients with breast cancer with aneuploid cells below the cut-off value showed a significantly longer DFS and OS than those with aneuploid cells above this value. Patients with node negative breast cancer with >10 aneuploid cells (>5c) and >1 highly aneuploid cell (>9c) showed an unfavourable prognosis similar to patients with node positive breast cancer with <10 aneuploid cells (>5c) and <1 highly aneuploid tumour cell (>9c) in DFS and OS.

CONCLUSION

Nuclear DNA content, as an objective marker of tumour aggressiveness, provides prognostic information in patients with both node negative and node positive breast cancer. Based on DNA aneuploidy, the clinically inhomogeneous group of patients with node negative breast cancer can be stratified into low-risk and high-risk subgroups. Therefore, DNA ploidy analysis may identify high-risk patients with lymph node negative breast cancer who might benefit from additional adjuvant therapy.

Thymidine labeling index: prognostic role in breast cancer

The aim of this study is to evaluate the prognostic role of thymidine labeling index in patients with breast cancer. Cellular proliferation rates in 155 breast cancer specimens were investigated by 3H-thymidine labeling index (3H-TLI). Median age was 47 years (range: 23-76). At presentation, 11 patients (7.1%) had stage I disease, 76 (49%) had stage II, 64 (41.3%) had stage III disease, and 4 (2.6%) had metastatic involvement. Patients were placed in 2 groups based on their proliferative indices. The cut-off level was assigned as the median TLI value of the whole group. Correlations between proliferative activity of the tumors based on 3H-TLI levels and various previously established prognostic factors, as well as the influence of proliferative activity on survival as a clinical outcome, were analyzed. The mean and median TLI values for the whole group of patients were 4.36 +/- 4.96% and 2.76% (range: 0-23.6), respectively. There was a significant association of nuclear grade with TLI (P = 0.04). Patients who were alive with no sign of disease at the final follow-up examination had a significantly lower median TLI rate than those who were either alive with disease or those who had eventually died with disease progression (3.7% versus 1.9%, respectively; P = 0.04). Patients with locally advanced disease (N2 + N3 involvement) had a significantly higher median TLI rate than those with local nodal involvement (N1) (3.4% versus 1.7%, respectively, P = 0.026). Furthermore, TLI levels showed a significant association with overall survival in patients with node-negative disease (P = 0.02). Based on the results of this study, it can be concluded that TLI plays a significant prognostic role in a subset of patients with node-negative breast cancer. Furthermore, TLI appears to have a predictive value for the clinical outcome of patients with breast cancer. These findings may justify a more aggressive therapeutic approach in patients with high TLI levels. Further large-scale, prospective studies are required before a definite conclusion can be reached.reached.

Prognostic and predictive role of proliferation indices in adjuvant therapy of breast cancer

In breast cancer, proliferative activity represents one of the biologic processes most thoroughly investigated for its association with tumor progression. In addition to the mitotic activity component of pathologic grading systems, several proliferation indices have provided independent information on prognosis and response to specific treatments in large retrospective studies. Recently, results from treatment protocols prospectively planned to test the clinical utility of proliferative activity have indicated that tumor cell proliferation markers identify two subsets among patients with lymph node-negative cancers: 1) those at a very low risk of relapse and 2) those who will benefit from regimens including antimetabolites. Future efforts should compare the prognostic accuracy of different proliferation markers, confirm preliminary evidence of a relationship between proliferation and response to specific systemic treatments, and standardize assay techniques to facilitate their transfer to general oncology practice.

Nuclear cytometric changes in breast carcinogenesis

Breast cancer is thought to originate through progressively aberrant precursor lesions, paralleled by increasing morphological changes. The aim of this study was to quantify nuclear features by image cytometry in invasive breast cancer and its early (hyperplasia) and late (ductal carcinoma in situ) precursor lesions, in order to objectively describe nuclear changes in the spectrum of proliferative intraductal and invasive breast lesions. Image cytometry was performed on tissue sections of 20 samples of normal breast tissue, 71 of usual ductal hyperplasia (UDH), nine of atypical ductal hyperplasia (ADH), and 11 of well-differentiated and 13 of poorly differentiated ductal carcinoma in situ (DCIS) lesions. The invasive breast carcinomas consisted of 19 well-differentiated and 24 poorly differentiated lesions. Through the spectrum from normal breast tissue to invasive carcinoma, progressive changes in many nuclear features were measured. Significant differences were found between nuclei of florid ductal hyperplasia compared with mild and moderate ductal hyperplastic lesions, suggesting that florid ductal hyperplasia may be a more advanced lesion than assumed and may contain cancer precursor cells. No differences were found between ADH and well-differentiated DCIS, suggesting that these lesions are closely related. Feature values of well-differentiated DCIS were comparable to values found in well-differentiated invasive carcinoma and the same applied to poorly differentiated DCIS and invasive lesions. These results support the hypothesis that breast cancer develops through different routes of progression, one leading to well-differentiated invasive cancer through well-differentiated DCIS, and one leading to poorly differentiated invasive cancer through poorly differentiated DCIS. In conclusion, image cytometry reveals progressive changes in nuclear morphological and subvisual chromatin distribution features in the spectrum from intraductal proliferations to invasive breast cancer. This provides evidence for a progression from usual to atypical ductal hyperplasia and then to invasive cancer, through different routes for well-differentiated and poorly differentiated lesions.

Nuclear morphology in breast cancer: is pleomorphism an illusion?

Nuclear pleomorphism is an underlying theme of cancer histology. Any medical practitioner, not just the pathologist, would have at one time or another in a Pathology practical class, looked at histopathology slides and convinced himself or herself that cancer cells indeed looked more variable in size and shape than nontumorigenic cells. However, data from our nuclear morphometric analysis of cells in breast cancer and adjacent benign tissues appears to suggest that the larger size of the cancer cell nuclei could make any change in nuclear shape and size more noticeable and apparent than their benign counterparts. We hypothesize that the phenomenon of nuclear pleomorphism is due partly to observational subjectivity.

Correlation between p53, c-erbB-2, and topoisomerase II alpha expression, DNA ploidy, hormonal receptor status and proliferation in 356 node-negative breast carcinomas: prognostic implications

Various new prognostic indicators have been identified for mammary carcinomas, but the issue of their significance remains unsettled. The prognostic impact of p53, c-erbB-2, and topoisomerase II alpha expression was investigated in relation to standard prognostic factors for carcinomas of the breast and to the tumour cell growth fraction. Paraffin-embedded specimens of 356 node-negative infiltrating ductal carcinomas were stained immunohistochemically using a polyclonal antiserum to c-erbB-2, and the monoclonal antibodies DO-1 (p53), Ki-S4 (topoisomerase II alpha), and Ki-S5 (Ki-67). The patients were followed for a median duration of 99 months. Both p53 and c-erbB-2 were significantly associated with high tumour grade, large tumour size, DNA aneuploidy, lack of steroid hormone receptors, young age, and increased topoisomerase II alpha and Ki-67 expression levels. The correlation of p53 and c-erbB-2 was not significant. Topoisomerase II alpha and Ki-67 scores closely paralleled each other, indicating that both reflect the proliferative activity of tumour cells. A univariate analysis of overall (OS), specific (SS), and disease-free survival (DFS) revealed all the above-mentioned parameters to be statistically significant except patient age, which was relevant only to overall survival. Multivariate analysis with inclusion of all covariates selected tumour size and proliferation (topoisomerase II alpha and Ki-67) indices as independent predictors of survival in all three models. No additional information was gained by p53 or c-erbB-2. It is concluded that the proliferative activity, as assessed by topoisomerase II alpha or Ki-67 immunostaining, is the most useful indicator of breast cancer prognosis, except for tumour size.

Quantitative study of ductal breast cancer--patient targeted prognosis: an exploration of case base reasoning

Current analytic methodologies allow the extraction, even from small tumor masses, of extensive information on the biologic characteristics of malignant lesions, such as tumor aggressivity, metastatic potential, drug resistance, and host interactions. Clinical practice now offers a wide range of therapeutic strategies. Information technological advances offer the opportunity to refer to very large data bases of patient anamnestic data, response to treatment and clinical outcome. There is a need to formulate therapy and prognosis for each individual case. Case based reasoning is a knowledge based methodology where the outcome for complex situations can be predicted by referring to a large data base of cases of known outcomes. The preliminary data obtained from this study suggest that case based reasoning may offer a promising approach to individual targeted prognosis.

Texture analysis of cerebral white matter in SIV-infected macaque monkeys

Image texture analysis is used in a wide variety of applications in medical research. Neurovirulent simian immunodeficiency virus (SIV) infection in monkeys is considered a good model for HIV-1 infection in humans and causes neuropathological changes in white matter which can include diffuse myelin pallor, subtle white matter astrocytosis, perivascular macrophage infiltrates, and microglial nodules with multinucleated giant cells. The ability of image texture analysis to quantify these changes was evaluated. Sections of thionin-stained brain tissue from eight male rhesus macaques ranging in age from 42-59 months were used. Four animals served as controls and four animals were infected with neurovirulent SIVmac239/17E-R71 by bone marrow inoculation. Images of cerebral white matter were captured and analyzed by calculating 13 textural features based on statistical analysis of spatial co-occurrence matrices. Statistical analysis of the results included multiple comparisons using the Newman-Keuls multiple range test. The effect of variation in background illumination used at image acquisition was also evaluated. Ten of the 13 textural features used in this study successfully discriminated between tissue from control and SIV-infected animals and were consistent with independent neuropathological assessment. Three textural features were highly sensitive to variation in background illumination and found not useful in this application.