Cytokinetic investigation of lung tumors using the anti-bromodeoxyuridine (BUDR) monoclonal antibody method: Comparison with dna flow cytometric data

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 intratumor proliferative heterogeneity, multiple-site sampling was performed. Proliferative heterogeneity seemed to be higher inter-tumor than intra-tumor. Finally, a positive correlation (p < 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.