PROLIFERATIVE CHARACTERISTICS OF HEAD AND NECK TUMORS - IN-VIVO EVALUATION BY BROMODEOXYURIDINE INCORPORATION AND FLOW-CYTOMETRY

Cell proliferation of head and neck cancers was studied in 52 patients using in vivo bromodeoxyuridine (BUDR) incorporation. Patients receiv ed 250 mg BUDR intravenously several hours prior to biopsy of the tumo r tissue. Bivariate flow cytometry was used and enabled us to rapidly obtain DNA ploidy, labelling index (LI), DNA synthesis time (TS) and t umor potential doubling time (Tpot). This method was found to be suita ble to obtain complete cytokinetic data in 46/52 (88.5%) patients. The mean BUDR LI was 7.9% (range 2-18%); mean TS was 11.6 h (range 6-28.5 h); mean Tpot was 5.7 days (range 2-30 days). BUDR LI and TS were sig nificantly correlated with histological differentiation grading: G(3) tumors showed higher LI values and shorter TS values than G(1)/G(2) tu mors. A similar correlation was found between LI or TS and tumor dimen sions. Tpot was also significantly lower in larger tumors, such as in those with a higher grading. No significant correlation was found betw een LI or TS and DNA ploidy (50% of the tumors in our series were DNA aneuploid), while Tpot was found to be 10 days in diploid tumors, comp ared to only 6.3 days for the aneuploid tumors (p < 0.05). All cases w ith documented lymph node involvement (N+) showed significantly higher LI, and shorter TS and Tpot values if related to nodal free ones (Tpo t = 10 days in N+ patients and 6.3 days in N- patients; p < 0.05). The results of this study suggest that the method employed is clinically feasible and could be a useful aid in defining the prognosis of head a nd neck cancer patients. Since cell kinetic information is readily ava ilable using this method, it could be incorporated into clinical trial s to improve the design of therapeutic strategies for cancer patients.