Cytokinetic studies of oral cancer cells using bromodeoxyuridine labelling in relation to factors influencing prognosis

Abstract

Cytokinetics of 27 untreated oral squamous cell carcinomas were evaluated by in vitro bromodeox- yuridine (BrdU) labelling. A mononuclear cell suspension was prepared for the labelling using collagenase and DNase treatment. The labelled cells were visualised by immunofluorescence staining with an anti-BrdU monoclonal antibody. The labelling index (LI%) was calculated by determining the percentage of BrdU labelled cells. The LIs of the carcinomas ranged from 3.8 to 19.2%. The LIs of poorly-differentiated (HG3) tumours were 2–3-fold higher compared with those of well-differentiated (HG1) and moderately-differentiated (HG2) carcinomas. Results also showed statistically significant (P < 0.0005) increases in LIs from nuclear grade 1 (NG1) to nuclear grade 3 (NG3) carcinomas. Higher LIs were observed in stage III/IV (10.82 ± 4.62; 10.36 ± 4.90) than those in stage I (6.87 ± 2.09) and II (7.14 ± 1.87) carcinomas. A significant (P < 0.0005) difference in LI values was found between the patients with positive and negative lymph nodes. Good correlation (r = 0.77) was exhibited between the LI values and mitotic counts (MC) of the specimens. These results on oral cancer cell proliferation seem to have prognostic implications.