Nuclear DNA contents and ploidy patterns of DNA histograms were measured using flow cytometry (FCM) for specimens of squamous cell carcinomas (SCC) obtained from the oral cavity, in order to investigate the relationship between DNA ploidy pattern and T classification, the mode of metastasis to cervical lymph nodes, and the histological differentiation of the tumors. The materials consisted of 27 cases of oral SCCs in which radical neck dissection was performed. DNA aneuploidy and DNA index (DI) were measured in the fresh specimens of primary lesions and those of formalin fixed paraffin embedded cervical lymph nodes. The cervical lymph nodes were examined in regard to lymph node metastasis routine hematoxylin-eosin staining.
DNA aneuploidy was found in 7 cases (25.9%), and DNA index ranged from 1.35 to 1.72. DNA index was over 1.5 in 6 from these 7 cases. Although all DNA aneuploidy cases showed cervical lymph node metastasis, 9 cases in the DNA diploidy group showed cervical metastasis (45%). The ratio of cervical lymph node metastasis between the DNA aneuploidy group and the DNA diploidy group was significantly different. DNA index tended to increse as tumor differentiation and there was no correration between T classification and DNA aneuploidy. However, the level of cervical lymph node metastasis was more advanced in the DNA diploidy group than in the DNA aneuploidy group. Three of 9 DNA diploidy cases (33.3%) showed advanced level 3 cervical metastasis. However, DNA aneuploidy cases showed only level 1 or 2 cervical metastasis. DNA aneuploidy pattern of cervical lymph nodes was detected in 2 ceses of the DNA diploidy group, and in 3 cases of the DNA aneuploidy group. DNA indexes from the cervical lymph nodes differed from those of the primary legions.
