Prognostic significance of DNA measurement determined by image analysis in human breast carcinoma

Analysis of DNA and morphometry in breast carcinoma

Feulgen-stained imprints and smears from 730 cases of invasive breast cancer were investigated using an image analysis system. From each tumor sample 100 cells were randomly scanned and several DNA and morphometrical parameters evaluated. Their prognostic value for a prediction of distant metastases within 5 years was investigated with the multivariate Cox regression analysis, which was performed for all consecutive cases, as well as for node-negative and node-positive patients separately. The multivariate analyses showed a strong prognostic value of the anisonucleosis (variation of nuclear radius) and the DNA histogram type in addition to the nodal status, the tumor size (pT), and the histological tumor grade. However, performing this analysis for both node-positive patients and for those without lymph node metastases demonstrated a different prognostic meaning of the variables. The combination of each of the group-specific variables led to a prognostic factor, which allowed an assignment of patients to several subgroups with significantly different risk for distant metastases. Thus, both a low-risk group of node-negative patients with a 5-year distant recurrence rate of only 5.8%, and a higher risk group of node-negative patients with a recurrence rate of 38.6% could be identified. Among the node-positive patients, a low-risk group with a distant recurrence rate of 8.6%, and also a high risk group with 69% distant recurrence, could be identified.

Evaluation and prognostic value of DNA content and of morphometric parameters in malignant mesothelioma using digital image analysis

Fifty-seven cases of malignant mesothelioma were analyzed for nuclear diameter, DNA content and ploidy-related parameters, using Feulgen stained paraffin sections with a digital imaging analysis system. Thirty cases had a mean nuclear diameter > 7 microns and 31 cases were classified as near-diploid. A statistically significant correlation between survival and the mean nuclear diameter (P = 0.0006) and between survival and DNA index (P = 0.007) was obtained. For other DNA content parameters (proliferation index, 5c exceeding rate), only one of the two statistical tests showed a significant correlation with survival while the other test was of borderline significance. In this malignant mesothelioma population, the prognosis for patients with the epithelial type was better than for those with sarcomatous tumours (P = 0.01). In this population of patients, about half of the malignant mesotheliomas were aneuploid. The mean nuclear diameter, DNA index analysis and proliferation index analysis of the tumour cells on Feulgen stained paraffin sections can be used as independent prognostic parameters.

Disease-free survival of node-positive breast cancer patients. Improved prognostication by cytometrical parameters

Feulgen stained cytologic samples from 225 node-positive breast cancers were investigated by means of an image analysis system. From each tumor sample, 100 cells were scanned and several DNA, morphometrical and textural parameters were evaluated. The meaning of the cytometric parameters for prediction of distant metastases within five years was investigated by the stepwise Cox regression analysis. Most of the investigated DNA- and morphometrical parameters, as well as one textural feature, showed a significant univariate correlation with the clinical course. In the multivariate approach, the lymph node status (pN) was the strongest prognostic factor, followed by the histogram type, the tumor size (pT) and a textural parameter (heterochromatin area). By the linear combination of these selected variables a multivariate prognostic factor was calculated for each individual patient. Using this factor, the patients could be splitted into four groups according to their risk for distant metastases. For this, the continuous range of the multivariate factor was subdivided so that about 35% of the patients were in the middle groups and about 15% of the patients in each of the border groups with highest and lowest factors, respectively. Thus a low risk group (lowest factors) of node-positive patients could be identified with a 5-year distant recurrence-rate of only 6.5%, as well as a group of patients with a considerably worse prognosis (highest factors) and a distant recurrence-rate of 67%. Therefore, DNA, morphometrical and textural parameters can provide powerful prognostic information in node-positive breast carcinomas. Using the multivariate combination of clinical and relevant cytometrical parameters may allow a more appropriate selection of patients for adjuvant therapy.

Improved prognostication in small (pT1) breast cancers by image cytometry

Feulgen-stained samples from 460 small (pT1) primary breast cancers were investigated by means of an image analysis system. Several DNA, morphometrical and textural parameters were evaluated for each patient, and the prognostic meaning of these parameters was then investigated by the Cox regression analysis. As prognostic criterion a distant recurrence-free survival of five years was considered. All investigated DNA- and morphometrical parameters as well as several textural parameters showed a significant univariate correlation with the clinical course. In a multivariate approach the axillary nodal status was the most important prognostic parameter, followed by a morphometric parameter (anisokaryosis) and two textural parameters (runlength and co-occurrence). None of the DNA histogram derived parameters could add prognostic information in this multivariate approach. By the linear combination of the four selected variables, an individual prognostic factor was calculated. Using this factor the patients could be split into several groups according to their risk for distant metastases. Thus a low risk group of pT1 patients could be identified with a distant recurrence rate of only 2% after 5 years, and also a group of patients with a considerably worse prognosis and a 5-year distant recurrence rate of 53%. In contrast, using the nodal status as single parameter allows the identification of a low risk group of patients (pN0pT1) with a distant recurrence rate of 10.6%. Therefore, morphometrical and textural parameters can provide powerful prognostic information in small breast carcinomas and may allow a better selection of patients for adjuvant therapy.

Image cytometry: current applications and future trends

Image cytometry has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. Modern image systems encompass morphometry, densitometry, neural networks, and expert systems. Rapid advances in technology and the development of user-friendly systems have provided pathologists with an alternative to flow cytometry, particularly useful in the evaluation of small or hypocellular specimens. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining. Newer uses under active investigation include development of expert systems that may act as diagnostic consultants in the future. Beyond DNA analysis, image cytometry holds great promise for improved tumor classification, for screening and surveillance in high-risk populations, and as a tool to improve diagnostic ability. This article discusses types of image analysis systems, specimen preparation, data acquisition, current applications in specific organ sites, and possible future applications.