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Biomedical subjects

B Nordin

Publications and source records attributed to B Nordin.

11 recordsLinked to original sources
PubMed1989

Cytophotometric estimation of cell proliferation in breast cancer. Correlation to the clinical course during long-term follow-up.

Tumours from 117 patients with breast cancer operated during a 5-month period 1975-1976 were investigated by absorbance scanning cytophotometry. The relations of these data to breast cancer recurrence and death during a follow-up period of 8.5 years were analysed using Cox's proportional hazards model. When individually tested, nodal status, grade of malignancy and high rates of proliferation, as indicated by cells in S-phase, were statistically significant predictors of the clinical outcome. The risk ratio associated with S-phase decreased significantly over time from primary treatment. No significant relation was found between DNA-ploidy or tumour size and the clinical course. In the multivariate analysis, based on 76 patients, nodal status alone was a significant prognostic factor.

Adult↗
PubMed1986

Image cytometry in malignancy grading of breast cancer. Results in a prospective study with seven years of follow-up.

A fully automated system for image cytometry is presented. In combination with a special tumor sampling procedure, the system proved able to record with high reproducibility a large number of tumor cell population descriptors of high prognostic significance in a prospective study of breast cancer. These included the degree of abnormality of DNA distribution (strongly correlated with the proliferative rate) and some descriptors of shape and texture (strongly correlated with the grading system for breast cancer suggested by the World Health Organization). While the extreme complexity of a true malignancy grading system for breast cancer is underlined, the results of this study indicate that its creation is a possibility, given sufficient effort by interdisciplinary teams using modern sophisticated analytical techniques.

Breast Neoplasms↗
PubMed1985

A program for logistic prediction modelling.

A computer program has been developed that can be used for analysing a binary outcome variable and a set of regressors of type interval with a logistic (i.e. nonlinear) model.

Biometry↗
PubMed1983

Histopathological systems of breast cancer classification: reproducibility and clinical significance.

The inter- and intraobserver reproducibilities of the histopathological systems of breast cancer classification suggested by the World Health Organisation (WHO), the Armed Forces Institute of Pathology (AFIP) and Ackerman have been analysed. The reproducibilities of the three classification systems were only "fair" to "moderate" and no correlation with the five-year recurrence rate was found. Our results indicate that these classification systems are without biological significance and are useless for prognosis in the individual patient. When the tumours were classified according to degree of differentiation (high, moderate, low) or graded according to WHO (which includes both differentiation and nuclear atypia), however, there was a significant correlation with the five-year recurrence rate. Yet even such "reduced" subdivisions are of no value in judging prognosis for the individual patient at the time of diagnosis; rather, they are useful only in the follow-up analysis of groups of patients.

Breast Neoplasms↗
PubMed1979

Carcinoembryonic antigen in serum of unselected breast-cancer patients and of non-hospitalized controls.

A series of consecutive unselected patients with primary breast carcinoma and their age-matched controls were studied for serum CEA in relation to clinical findings. Raised CEA was found in a similar frequency in patients with primary breast cancer (pre- and postoperative) and in the control women: 16%, 11% and 11%, respectively, exceeded the selected upper limit of the reference range (13 ng/ml) with a double-antibody radioimmunoassay. In the breast-cancer patients, however, 48% of the raised CEA levels exceeded 16 ng/ml, compared with only 20% in the controls. Significant correlations (r approximately 0.3) were found between CEA levels and tumour size, TNM classification and a combined clinical and histopathological classification. A high frequency of raised CEA values in the advanced breast-cancer patients was the essential contribution to these positive correlations. A correlation coefficient of 0.6 was found between pre- and postoperative CEA values. The frequency of smoking and/or chronic disease was unexpectedly high in patients as well as in controls with high CEA.

Adult↗
PubMed1979

Analysis of reproducibility of subjective grading systems for breast carcinoma.

The inter- and intra-observer reproducibility of three grading systems for breast cancer has been analysed: those of the World Health Organisation, of Black, and of Hartveit. In addition, the components forming the basis of these grading systems were analysed separately with regard to reproducibility and interrelationship. In this analysis, degree of differentiation was also included as a parameter. The grading systems of WHO and of Black gave a stratification of the material into three categories of tumours, but that of Hartveit did not. All three systems had a low inter- and intra-observer reproducibility. Truncated component analysis indicated that the grading systems of WHO and of Black are closely related to each other and to the 'nuclear lobulation' component of Hartveit's system. The components 'pleomorphism', 'mitotic frequency', and 'hyperchromasia' of the WHO system were closely interrelated. Descriptors such as 'differentiation' and 'tubule formation' were interrelated but acted in a different direction from the others.

Breast Neoplasms↗
PubMed1979

High resolution segmentation of cervical cells.

A major problem in the automation of cervical cytology screening is the segmentation of cell images. This paper presents the present status of the work on that problem at the University of Uppsala. A dual resolution system is used. Suspect malignant cells are located at 4 mu resolution. Each such cell is rescanned at 0.5 mu resolution at two different wavelengths, 530 and 570 nm. The nucleus and the cytoplasm are isolated each by two independent methods. For the nucleus adaptive thresholding in the histogram of the 570 nm image and a contouring in a radially transformed version of that image is used. For the cytoplasm a two dimensional thresholding in the 2D histogram and a contouring in a radially transformed version of the 530 nm image is used. If the two nuclear masks agree the surrounding area is checked for disturbing objects. If also the cytoplasm masks agree and are without disturbing objects the whole cell is accepted. The result of the cytoplasm masks agree and are without disturbing objects the whole cell is accepted. The result of the segmentation is thus three categories; free cells, free nuclei and rejected objects. The shape of the objects belonging to the former two categories is checked and irregularly shaped ones are rejected as probably consisting of several overlapping nuclei. Cells passing also this test are classified as normal or malignant. The experience from using this algorithm is discussed and areas for further research are pointed out.

Cell Nucleus↗
PubMed1978

Computer analysis of cervical cells. Automatic feature extraction and classification.

A prescreening instrument for cervical smears using computerized image processing and pattern recognition techniques requires that single cells in the specimen can be automatically isolated and analyzed. This paper describes a dual wavelength method for automatic isolation of the cytoplasm and nuclei of cells. Density-oriented, shape-oriented and texture-oriented parameters were calculated and evaluated for more than 600 cells. It is shown that the computer can be taught to distinguish between normal and atypical cells with an accuracy of ca. 97%, while human classification reproducibility is ca. 95%. In addition, an attempt to assign a measure of atypia to individual cells is described.

Cell Nucleus↗
PubMed1978

Computerized nuclear morphometry as an objective method for characterizing human cancer cell populations.

A new method for measuring differences in nuclear detail in chrome alum gallocyanin-stained nuclei of cells from human breast cancers was compared with conventional subjective grading and classification systems. The new method, termed computerized nuclear morphometry (CNM), gives a multivariate numerical score that correlates well with nuclear atypia and gives a higher reproducibility of classification than do subjective observations with conventional histological preparations. When 100 individual nuclei from each of 137 breast cancers were examined by CNM, there was a broad CNM score variation between patients but a good reproducibility for each tumor. When different parts of the same tumor were sampled, there was good reproducibility between samples, indicating that some breast cancers at least are "geometrically monoclonal." When these cancers were compared by the grading systems of WHO and Black, correlations of 0.43 and 0.48, respectively, were found. There was a poor correlation between CNM and classifications of tumor type, but in general there were high values for CNM in medullary tumors and low values in mucous tumors. Correlations between CNM and tumor progression and prognosis await future study of patients participating in the study.

Breast Neoplasms↗