Cellular heterogeneity in human transitional cell carcinoma: an analysis of optical properties and lectin binding.

Flow cytometry was used to measure the binding of a panel of ten fluorescein isothiocyanate(FITC)-conjugated lectins to fifteen samples of normal and neoplastic human urothelium. Concurrent measurement of light scattering and fluorescence permitted the quantification of lectin binding to cellular subpopulations defined by their light-scattering properties. In normal urothelium, we previously demonstrated levels of lectin binding to the cellular subpopulations derived from the superficial and intermediate cell layers which were higher than levels which bound to the subpopulation derived from the basal cell layer (Ward et al., 1987). This difference was most marked with Maclura pomifera agglutinin (MPA), Ricinus communis agglutinin (RCA) and Ulex europeus agglutinin (UEA). We now report a similar correlation between the degree of differentiation of a cellular subpopulation and the level of lectin binding in human transitional cell carcinomas (TCCs). Morphological differentiation in human TCCs is accompanied by alterations in cell-surface carbohydrates which are similar to those which accompany cellular differentiation in the corresponding normal tissue. No systematic difference in lectin binding was observed between the corresponding subpopulations of normal and neoplastic urothelial cells.

Clinical trials in cancer: the role of surrogate patients in defining what constitutes an ethically acceptable clinical experiment.

Doctors who treat lung cancer in Ontario were previously asked how they would wish to be managed if they developed non-small cell lung cancer and whether they would consent to participate in six clinical trials for which they might be eligible. The proportion of these expert surrogate patients who would consent to each clinical trial ranged from 11 to 64%. The results of this study were transmitted to the same group of doctors who were asked to comment on the ethical acceptability of each trial in the light of this information. The majority of physicians said that those trials to which less than 50% of expert surrogates consented should not have been opened to patients. Sixty-nine per cent of doctors thought that new trials should be evaluated in this way. We also present the results of a survey of 400 lay people in Ontario who were asked to imagine that they had lung cancer and whether they would consent to participate in two of these same clinical trials. Fifty per cent of lay people consented to a randomised trial of lobectomy versus segmentectomy in early, operable disease (LCSC-821) compared to 64% of expert surrogates, and 48% of lay people consented to a randomised trial of five different forms of chemotherapy in metastatic disease (SWOG-8241) compared to 19% of doctors. It was concluded that the lay people were unable to discern differences in the acceptability of clinical trials which were clear to experts in the field. Subsequently, respondents were told about the decisions which doctors would make in the same circumstances and asked if this information would modify their previous decisions. There is no net change in the proportion of patients consenting to the surgery trial but the proportion of people consenting to the chemotherapy trial decreased by 40%. The majority of lay people said that they would wish to have access to this type of information before consenting to participate in a clinical trial.

Cellular heterogeneity in human epithelial neoplasms.

Tumor cell heterogeneity has in recent years been the subject of numerous excellent review articles, but comprehensive reviews may not always distinguish between that which is known about tumors from direct observation and that which is inferred from the study of analagous systems. The purpose of this review is to describe what is known about cellular heterogeneity in human tumors and to discuss current models of the pathogenesis of cellular heterogeneity in light of the evidence available from the study of human cancer.

Cellular heterogeneity in normal and neoplastic human urothelium: a study using murine monoclonal antibodies.

To assist in the description of the cellular heterogeneity present in normal and neoplastic urothelium, a panel of monoclonal antibodies (MoAbs) was raised against human transitional cell carcinoma (TCC) of the urinary bladder. All immunizations were carried out using whole cells and membrane preparations from well differentiated human TCCs. Two fusions produced 145 hybridomas. Following primary screening by ELISA and secondary screening with immunohistochemistry, three useful antibodies were identified. MoAb 35.48 binds to all cell layers of the normal urothelium and well differentiated tumours, but not to the majority of poorly differentiated tumours. MoAb 21.48 binds preferentially to the basal cell layer of normal urothelium and to some well differentiated papillary TCCs, but poorly differentiated tumours exhibit diffusely positive staining. MoAb 21.48 also shows cross-reactivity with basal cell layers of other epithelia. MoAb 5.48 binds preferentially to the superficial cell layers of normal urothelium and well differentiated TCCs, but exhibits less binding in poorly differentiated tumours with loss of the preferential superficial staining. Quantitative flow cytometric studies indicate that MoAb 5.48 binds to a cell-surface antigen which is present on significantly fewer cells of poorly differentiated tumours than on either normal urothelium (P less than 0.05), or well differentiated tumours (P = 0.05).