Identification of second malignancies on effusions and fine-needle aspirates using a panel of monoclonal antibodies

Abstract

Summary The longer survival of neoplastic patients achieved through improvements of therapeutic regimens has increased the relative risk of developing a second primary tumour (SPT). In this context, conventional cytopathology can define tumour histotype only in a small fraction of cases. In this study, we have evaluated whether selected combinations of monoclonal antibodies (MAbs) to tumour-associated antigens (TAAs) al, 1986;Tucker et al, 1988) and solid tumours (Lee, 1986;Kaldor et al, 1987). As early diagnosis of SPTs has major therapeutic and epidemiological relevance (Kaldor et al, 1987;Giardini et al, 1993), the development of new methods for the accurate detection of second malignancies should be attempted. In this context, exfoliative and FNA cytology may be considered a valuable and accurate diagnostic technique, easy to perform on a large scale during the follow-up of patients previously treated for malignant tumours. These methods also have the advantage of minimal morbidity and low cost (Koss, 1988). While this approach has been reported to be highly accurate in identifying metastatic cells, the possibility of defining the tumour histotype has been far less successful (Friedman et al, 1983;Hajdu et al, 1984). We have previously reported that the use of selected combinations of MAbs to TAAs can be applied to a number of areas of cytodiagnosis of solid tumours, thus increasing the accuracy of conventional morphology in identifying metastases from unknown primary tumour and in differentiating primary from metastatic lesions (Mottolese et al, 1993). In the present study, we have analysed, in a large group of patients with a past history of malignancy, whether the use of a similar panel of reagents may also be useful in detecting SPTs in two areas of cytopathology, which are particularly difficult on the basis of morphological criteria, namely that of effusions and of pulmonary FNA. MATERIALS AND METHODS PatientsFrom January 1990 to June 1995, 334 cytological specimens, of which 91 were pulmonary FNA and 243 pleural and peritoneal effusions sampled from patients previously treated with chemo and/or radiotherapy for different malignant tumours, were analysed both cytologically and immunocytochemically (ICC). The series consisted of 93 patients with effusions and 52 with solitary or multiple pulmonary masses, which appeared within 5 years of a previous tumour, while 189 patients developed effusions (150 cases) or radiologically assessed lung lesions (39 cases) at least 5 years after the first tumour. Only those cases in which morphological examination assessed the presence of malignant cells on cytological specimens have been included in this study. Unsatisfactory or insufficient specimens were excluded. Preparation of cell substratesPleural and peritoneal effusions were collected in sterile conditions using heparin (Liquemin Roche) as anticoagulant. Samples were centrifuged at 160 g for 10 min and the recovered cells were resuspended, after three washings with Hanks' balanced salt solution (Gibco Labor...