Cells coming from normal and neoplastic human lung tissue were analyzed by means of FT-IR microspectroscopy. Among the various methods tested to isolate the cells, mechanical treatment alone was found to yield the best results. Monolayers of cells were homogeneously distributed by cytocentrifuge preparation on BaF2 windows, and several spectra were obtained for different circular micro-areas of the order of one hundred microns in diameter. This procedure made it possible to obtain reliable spectra and to reject those containing additional bands due to impurities arising from the isolation treatment. Spectral differences between normal and neoplastic cells reflect an increase in the intensity of the bands corresponding mainly to PO2− symmetrical and asymmetrical vibrations of DNA in pathological samples with respect to normal ones. The value of the ratio of the integrated areas of the bands at 1080 and 1540 cm−1 due to DNA and proteins, respectively, makes it possible to differentiate between normal and abnormal cells, thus suggesting the use of this parameter as an original approach in the recognition of early neoplastic transformation undetectable by means of traditional procedures.

In order to investigate the cytokinetics of malignant tumors and non-malignant lesions of the lung, tissue samples from 57 patients affected by non-small-cell carcinoma (NSCLC), small-cell carcinoma (SCLC), and benign and inflammatory lesions have been analyzed using the BUdR monoclonal antibody (MAb) method. This method is based on the preparation, at the time of surgery, of viable monocellular suspensions (using collagenase and DNase treatment) and the concomitant administration of BudR. The percentage of BudR-labelled cells was monitored by fluorescent microscopy using an FITC-labelled second antibody. In NSCLC, each histological group showed a wide range of labelling index (LI) values. On the contrary, SCLC exhibited a more homogeneous kinetic behaviour as evidenced by a narrowly distributed, higher LI. Tumors shown to be diploid by flow cytometry did not show a lower LI than aneuploid tumors. Furthermore, differences were constantly observed between the S-phase percent calculated using BUdR and that calculated using the DNA flow cytometric (FC) histogram, the latter always showing higher S-phase values. In an attempt to study the intra-tumor proliferative heterogeneity, multiple-site sampling was performed. Proliferative heterogeneity seemed to be higher inter-tumor than intra-tumor. Finally, a positive correlation (p less than 0.05) was found between LI and the actual doubling time (DT) of the primary tumor mass, evaluated using sequential radiographs. In conclusion, the present BUdR method can be considered a useful source of relevant information on in vivo cell growth, in parallel to other clinical (DT) and biological (DNA content) approaches.

Cells from a group of 185 patients suffering from malignant tumours (160 non-small-cell lung carcinoma, 13 small-cell lung carcinoma, and 12 non-epithelial tumours) and 6 with benign lung tumours were studied by flow cytometry in order to detect the prognostic value of DNA content. A total of 144 (90%) non-small-cell lung carcinomas (NSCLC) and 8 (62%) small-cell lung carcinomas (SCLC) exhibited aneuploidy. Furthermore 52% (83 patients) NSCLC, 24% (3 patients) SCLC and 50% (6 patients) non-epithelial tumours demonstrated multiclonality. Benign cases showed diploid DNA content. For actuarial survival analysis using the Bergesson and Gage method and the Greenwood variance, 142 patients were selected. Statistical comparisons were made by the use of the t-test for unpaired data between fixed times. No correlation was observed between ploidy and stage, histological grading or treatment modality. A statistically significantly better survival was observed after 12, 18 and 24 months of follow-up for diploid and monoclonal (with the exclusion of hypo- and hypertetraploid) patients. Thus, flow-cytometric DNA analysis may be useful in prognostic assessment of human lung tumours.