HISTOSCAN: computer program for cytophotometry in tissue sections and its application in the evaluation of nuclear atypia

Folate status among patients with non-small cell lung cancer: a case-control study

BACKGROUND AND OBJECTIVES

This case control study explored the purported inverse relationship between folate status and lung cancer development.

METHODS

Folate status of 46 postoperative non-small cell lung cancer (NSCLC) patients was compared to that of 44 non-cancer patients. Cancer patients had completed treatment > 3 months prior and had no evidence of cancer. Ineligibility criteria for all patients included (1) > 2 alcoholic drinks/day (2) ongoing tobacco use, or (3) folate supplementation > 400 microg/day.

RESULTS

No differences were found between groups in serum and RBC folate after adjustment for age and use of folate-interfering medications: geometric means (GM) x /geometric standard error (GSE): 7.9 ng/ml x /1.1 vs. 7.8 ng/ml x /1.1, respectively (P = 0.91) for serum folate; 264 ng/ml x /1.1 vs. 263 ng/ml x /1.1, respectively (P = 0.97) for RBC folate. Age- and creatinine-adjusted homocysteine was no different between groups: GM x /GSE: 9.4 micromol/L x /1.0 vs. 8.6 micromol/L x /1.0, respectively (P = 0.17). No difference were seen in folate intake. Frequencies of the homozygous genotype for the MTHFR polymorphism, an enzyme important in folate metabolism and associated with a reduced risk of other cancers, were no different.

CONCLUSIONS

This case control study does not support the hypothesis that low folate is an independent risk factor for NSCLC.

Single cell DNA cytophotometry in clinical stage I malignant melanoma. Relationship to prognosis

Histological sections of 50 clinical stage I cutaneous melanomas were analyzed by single cell DNA cytophotometry. Forty-two percent of the melanomas had diploid modal values. Ploidy was not significantly related to the level of invasion, melanoma thickness or prognosis. These results are contradictory to published data from flow cytophotometry which, however, differ inter alia concerning patient materials and follow-up times. Mean nuclear area was in our study significantly correlated to the prognosis.

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.

Molecular aspects of mast-cell-mediated mitogenesis in fibroblasts and mesothelial cells in situ

Mast-cell-mediated mitogenesis in intact tissues is a paracrine reaction the molecular mechanisms of which still have to be elucidated. One strategy worth exploring is to study the mitogenic reaction under as defined conditions as possible. The present study demonstrates that in the virtually avascular rat mesentery, organ-cultured in a biochemically-defined medium, activation of mast cells induced a mitogenic reaction in fibroblasts and mesothelial cells, the two predominant, morphologically distinct neighboring cell types. Thus the system provides a means of studying the influence of defined molecules in the growth medium on the outcome of a mitogenic response in these two cell types in situ. It was further observed that exogenous platelet-derived growth factor (PDGF) was not essential for this mast-cell-mediated mitogenic reaction to occur in the tissue-bound fibroblasts and mesothelial cells.

A rapid system for static cytofluorometry enabling the simultaneous determination of nuclear size and DNA content

A measuring technique enabling the simultaneous determination of nuclear size and DNA content by single cell cytofluorometry is described. The system is based on a Leitz MPV cytophotometer, a Zeiss scanning stage and a microcomputer system. Cells to be measured are not positioned in the ordinary way, but are passed through the excitation light beam. In this way rapid measurements are achieved. Further, an estimate of the object diameter is calculated from the pulse shape obtained as the fluorescence is recorded continuously by using a circular measuring aperture, congruent with the excitation light field. Repeated measurements of nuclei stained with Hoechst 33258 showed a high reproducibility for DNA content with a coefficient of variation (CV) below 1% and an acceptable precision for nuclear area with a mean CV of 7%. Nuclear area estimated by the method was well correlated to area determined from photographs (r = 0.986). Disintegrated samples from eight patients with breast cancer were analyzed and compared to Feulgen-stained samples analyzed by scanning cytophotometry. Scatter diagrams illustrating DNA content and nuclear size showed essentially the same distribution with the two methods. We conclude that the system may be a rapid alternative when fluorescence together with object size are quantified in slide preparations.

Prognostic factors in locally advanced breast cancer (T3, T4) with special reference to tumor cell DNA content

The prognostic value of DNA analysis was studied retrospectively in 91 patients with locally advanced breast cancer (T3, T4) and a follow-up time of 3-7 years. Tumor cell DNA analysis was performed by static cytometry on aspiration biopsy specimens in 42 cases and on tissue sections in 49 cases. The tumors were classified as euploid or aneuploid. Sixty-four percent of the tumors were aneuploid. DNA pattern correlated significantly to histologic grade and axillary perinodal growth and also to survival. DNA pattern, histologic grade and axillary node metastases correlated significantly to disease-free survival (DFS). In this series of patients with locally advanced breast cancer DNA determinations gave important prognostic information.

DNA-cytophotometry of benign compound and intradermal naevi, Spitz epithelioid naevi and malignant melanomas

Single cell DNA cytophotometry was used to characterize seven compound, ten intradermal and six Spitz naevi as well as 23 primary cutaneous malignant melanomas. Compound and intradermal naevi were characterized by a smaller nuclear area than both Spitz naevi and malignant melanomas. Tumour ploidy could not be used as a single criterion of malignancy since both diploid and hyperdiploid melanomas were encountered. The very low mean optical density of Spitz naevi served to distinguish these lesions from malignant melanomas.

Prognostic value of DNA content in colorectal carcinoma. A flow cytometric study with some methodologic aspects

The DNA content of 37 colorectal carcinomas was studied prospectively by flow cytometry. The DNA content from the same tumors was also studied in disintegrated paraffin sections. The methods gave similar information on the DNA content and the correlation was 0.94. In eight patients tumor imprints were prepared and the DNA content was analyzed with static cytometry. A correlation coefficient of 0.83 between flow cytometry on fresh tumor tissue and static cytometry was found. Sixty-two percent of the tumors were aneuploid and had significantly higher S-phase values than diploid tumors. Histologic grade was not related to ploidy level, whereas Dukes' C tumors often were aneuploid. When the clinical course of patients was analyzed by log rank test (mean follow-up, 30.4 months), the patients with diploid tumors showed a clear advantage in terms of survival; only two patients in this group developed progressive disease. It is concluded that the DNA content is an independent prognostic predictor of colorectal carcinoma and that DNA can be analyzed by several methods. Of these, the method using disintegrated paraffin sections appears most attractive.

DNA cytophotometry of acinic cell carcinoma and its relation to prognosis

Single-cell DNA cytophotometry has been assessed on histological sections or aspiration biopsy smears from 13 parotid acinic cell carcinomas and has been related to prognosis. The minimal follow-up was 6 years. Six ACC were well differentiated and seven moderately well differentiated. The modal DNA values of all tumours examined were in the diploid area. The number of nuclei above 2.5C DNA, expressing proliferative ability or aneuploidy, was low. A difference, too small to be of value for prognostic purposes, was found between the non-recurrent tumours (6%) and the metastasizing tumours (16%). The DNA levels measured in the present tumour material correspond to the concept of ACC as being a well differentiated neoplasm. The nuclear DNA pattern of these tumours would seem to be of minor prognostic significance with regard to survival time and/or potential for metastasis.

DNA content and prognosis in renal cell carcinoma. A comparison between primary tumors and metastases

Deoxyribonucleic acid (DNA) content was retrospectively determined by single-cell cytophotometry in primary tumors and corresponding metastases from 32 patients with renal cell carcinoma. In 15 of the primary tumors a diploid/near diploid and in 17 an aneuploid DNA content was found. A diploid/near diploid DNA pattern was revealed in 10 metastases and 22 were aneuploid. By comparing the DNA content in the primary tumors with their metastases, 13 of 32 showed a clear divergency, which might illustrate tumor cell heterogeneity of renal cell carcinoma. The DNA pattern showed a close correlation to morphologic grading. A correlation between DNA content in the metastases and survival time was found. Patients, with diploid/near diploid metastases survived significantly longer than those with aneuploid DNA contents (mean, 31.1 and 11.5 months, respectively; P = 0.004). In contrast to this, no correlation was found between DNA content in the primary tumors and survival time.

Metastasizing APUD cell tumours of the human gastrointestinal tract. Light microscopic and karyometric studies

A total of 11 metastasizing gastrointestinal APUD cell tumours from biopsy and autopsy files were reclassified according to Soga and Tazawa as well as to WHO Histologic Classification of Tumours. The much higher proportion of APUD cell tumours in autopsies (11 cases from 1000 autopsies in comparison with 22 cases from 22 000 biopsies) demonstrate that the majority of them will not be discovered during the patient's life. EC cell carcinoids (type A) predominate in both non-metastasizing and metastasizing gastrointestinal APUD cell tumours. Metastases from EC cell carcinoids occurred only in regional lymph nodes and in the liver. The APUD cell tumours originating in the pancreas represent the most frequently metastasizing gastrointestinal carcinoids. Besides in the liver and in regional lymph nodes metastases from pancreatic APUD cell tumours were seen in the skin, the brain and the skeleton. One case with two (pancreatic, bronchial) competitive primary APUD cell tumours and a skin metastasis was studied by means of automated cell image analysis. Cell populations of these three tumour sites were characterized by morphometric and densitometric nuclear parameters. It could be demonstrated that the skin metastasis consisted of a cell population, which occurred as a subpopulation in the primary tumour of the bronchus. The results of karyometric investigations supported the hypothesis that single components of tumours can metastasis selectively.

Juvenile laryngeal papilloma: histologic and photometric evaluation of atypia

Juvenile papillomas are the most common proliferative laryngeal lesion in children. Atypia may be present but is difficult to interpret owing to the basically benign character of the lesion. A histologic and clinical classification of 23 cases of juvenile laryngeal papillomas was performed following the criteria suggested by Quick and co-workers in 1979 and intended to enable the clinical course to be more accurately predicted. The various histologic types of papillomas were characterized by single-cell microdensitometry. The photometric study verified the increase in the relative width of the proliferative zone with the degree of atypia. Severe atypia was the only histologic type associated with hypertetraploid nuclei. The frequent occurrence of mild atypia was unrelated to the clinical course. The moderate and severe degrees of atypia were more common during periods of relatively frequent operations. Severe atypia was rare but in one patient it heralded the development of invasive carcinoma.

An evaluation of Feulgen-acriflavine-SO2 and Hoechst 33258 for DNA cytofluorometry in tumour pathology

The performance of Feulgen-acriflavine-SO2 and Hoechst 33258 for cytofluorometric ploidy determination is evaluated and compared. The fast initial fading of acriflavine-SO2 stained nuclei, with substantial reduction in fluorescence intensity within about 10 ms, is shown to be related to changes in DNA-ratios between cell types when measurements are performed using different excitation light intensities. Although low intensity excitation-, without such fading-, was used, the acriflavine-SO2 staining procedure showed large specimen to specimen variability regarding both mean fluorescence intensities and coefficients of variation (CV). The cells in such specimens could be shown to contain the same amount of chromophore using scanning absorbance measurements and the differing fluorescence values therefore probably represent variability in fluorescence yield. Specimens stained with Hoechst 33258 after RNase treatment showed very small deviations in mean fluorescence value between slides, and also much lower CV's than in acriflavine-SO2 stained specimens. The results indicate that with proper internal standards this procedure would allow the detection of deviations in DNA content in the order of 2%.

A fast and reliable system for microcomputerized DNA cytofluorometry in tumour pathology

A microcomputerized cytofluorometry system based on a Leitz MPV 3 cytophotometer, and intended for DNA measurements in tumour pathology is described. The system has been equipped with a reference channel for correction of excitation light instability. The importance of the adjustment of the epi-illumination for optimal performance of the reference channel is stressed, and a detailed description is provided. An apparatus variability well below 1% CV is obtained even during periods of marked instability of the arc-lamp. Software for conventional cytofluorometry with which about 200 cells can be measured in 20 min is presented. In addition a measuring technique where cells are not positioned, but are just passed through the excitation light spot is described. Preliminary results on cytocentrifuged specimens of human cancers indicate that this system is at least three times faster than conventional fluorometry. The increased speed of measurements considerably extends the possibilities to evaluate cell proliferation using static cytofluorometry. The measuring capacity of course is dependent upon the quality of the specimen. In well prepared cytocentrifuged specimens 1000 cells have been measured in 35 min.

Histopathological subgrouping of WHO II urothelial neoplasms by cytophotometric measurements of nuclear atypia

The grade of nuclear atypia was objectively assessed in 21 cases of non-invasive WHO II transitional cell bladder neoplasm. Measurements were performed by stage scanning absorbance cytophotometry, registering nuclear optical density, nuclear area, and the variability of these two factors, in 5 microns thick Feulgen-stained paraffin sections. The material was subgrouped into a 2- and a 2+ group according to the degree of histopathological atypia. Cytophotometrically determined atypia showed close correlation to the subjectively judged atypia, and there was no overlap between 2- and 2+. A difference in tumour ploidy level between different WHO II tumours is the most likely explanation of the grouping recorded.

Cytophotometric characterization of the WHO grades of transitional cell neoplasms

The WHO classification of urothelial bladder tumours is widely used, but does not seem to be entirely satisfactory. The main problem is the unhomogeneous WHO II group, and borderline cases in particular are difficult to evaluate histopathologically. Objective assessment of atypia would allow more reliable correlation between morphology and biological behaviour of the tumours to be made. We describe measurements of atypia in 3 characteristic cases of papillary bladder tumour of each WHO grade I, II, and III using Feulgen-DNA-cytophotometry. The mean optical density and nuclear area is determined in 5 micron thick tissue sections. The optical density and nuclear area for each specimen are plotted in a scatter diagram, and the position and variability of the cluster are evaluated. Cytophotometric characterization resulted in defined groups of WHO-graded tumours, and due to this encouraging result the method will be applied in a more comprehensive study of WHO II carcinomas.

Cytophotometric determination of nuclear size and DNA distribution in different hyperfunctioning thyroid lesions

Nuclear enlargement in hyperfunctioning thyroid lesions which has been found in earlier cytophotometric studies is also one of the criteria in the subjective histological estimation of thyroid function. Histopathological assessment is, however, often unreliable. In the present study stage scanning cytophotometric measurements in Feulgen-stained tissue sections were used to determine the nuclear changes encountered in non-toxic and toxic nodular goitre, and in toxic diffuse goitre. To ensure optimal selection of specimens for measurements autoradiography was used. Specimens of toxic diffuse goitre invariably had enlarged nuclei, but no difference was found between nodules in nontoxic and toxic nodular goitre. In fact, the same nuclear area was found in hot nodules, warm nodules and perinodular tissue in non-toxic nodular goitre, and in hot nodules in toxic nodular goitre. Thus there are lesions with clear-cut clinical, biochemical, and autoradiographic hyperfunction that do not have enlarged nuclei. Against this background it is possible that the nuclear enlargement present in toxic diffuse goitre reflects the disorder in itself and not the hyperfunctioning state. Hyperdiploid cell nuclei were found in all cases of toxic diffuse goitre and in a higher percentage than in the other lesions. It was not possible to distinguish nontoxic and toxic nodular goitre on this basis.