DNA ploidy as a predictor of cervical metastasis in advanced squamous carcinoma of the tongue.

Flow cytometric analysis of nuclear DNA content was performed in 34 squamous cell carcinomas of oral cavity and base of tongue tumours using archived paraffin-embedded tissues. The DNA content was correlated with the presence of cervical metastasis. Ten and 24 patients were classified as early (I & II) and advanced (III & IV) clinical stages, respectively. The DNA index (DI) was grouped into diploid (DI 0.85-1.15) and non-diploid. Seven (70%) tumours were non-diploid in clinical stages I & II. Four out of 7 (57%) developed initial and late cervical lymph node metastasis (p > 0.05). There were 15 (62.5%) non-diploid tumours in clinical stages III & IV. Thirteen out of 15 (86.7%) had cervical lymph node metastases (p < 0.05). However, the survival period and the incidence of recurrent disease for the whole group did not show any association with DNA ploidy. Our results suggest that DNA content may be useful as a reliable predictor of regional metastasis in advanced stage carcinoma of the tongue.