PROGNOSTIC-SIGNIFICANCE OF DNA-PLOIDY IN ORAL SQUAMOUS-CELL CARCINOMAS - A RETROSPECTIVE HOW AND IMAGE CYTOMETRIC STUDY WITH COMPARISON OF DNA-PLOIDY IN EXCISIONAL BIOPSY SPECIMENS AND RESECTION SPECIMENS, PRIMARY TUMORS, AND LYMPH-NODE METASTASES

Deoxyribonucleic acid ploidy was determined in paraffin-embedded tumor tissue from 116 patients with primary oral squamous cell carcinomas ( including 5 carcinomas of the lip and 14 of the tongue) by means of fl ow cytometry. One hundred six cases were suitable for evaluation (91%) . Sixty-eight percent of the cases (n = 72) showed a nondiploid nuclea r DNA content. Nondiploidy correlated significantly with presence of l ymph node metastases (p < 0.02) but not with tumor stage, grading (Wor ld Health Organization), or relapse-free and overall survival. Carcino mas of the lip and tongue turned out to be diploid more frequently tha n other oral squamous cell carcinomas (p = 0.002). In the 21 cases in which a comparison of DNA content of excisional biopsy specimens and s ubsequent resection specimens was possible a difference in DNA ploidy was found in one case only. The comparison of primary tumors and their lymph node metastases in 30 cases revealed a discrepancy of DNA conte nt in five cases (17%), which was connected with a shift from nondiplo idy to diploidy in four out of five cases. Fifty cases studied in para llel by means of image cytometry with Feulgen-stained tissue sections exhibited a concordance of the ploidy status in 87% and a significant correlation of the DNA index values obtained with both methods (p < 0. 01). These results demonstrate that DNA ploidy in oral squamous cell c arcinomas is distributed rather homogeneously within the tumors and re mains rather stable in the lymph node metastases. Despite a significan t correlation between nondiploidy and presence of lymph node metastase s, ploidy failed to be a statistically significant parameter for progn osis in oral squamous cell carcinomas in our investigation.