Comparison of flow cytometry with static densitometry in papillary thyroid carcinoma.

The prognostic accuracy of flow cytometric and static densitometric DNA analysis was compared in 31 patients who had undergone surgery for papillary thyroid carcinoma between 1959 and 1978 (median follow-up 18 years). There were five deaths from papillary thyroid carcinoma. Three of six patients with DNA aneuploid tumours on flow cytometry died (P greater than 0.05, Fisher's exact test) compared with four of eight patients whose tumours were found to be aneuploid by static densitometry (P less than 0.02). When quantitative analysis was applied to the static densitometry data, all five patients who died from papillary carcinoma were distinguished, with no false positives (P less than 0.002). The prognostic accuracy of flow cytometric DNA analysis is less than that of static densitometry in which morphological selection of malignant cells permits quantitative measurements. DNA analysis may add refinement to existing scoring systems in predicting the risk of death from papillary thyroid carcinoma. Such information could provide the basis for controlled prospective evaluation of bilateral resection as opposed to lobectomy in defined high risk patients. At present there is insufficient evidence upon which aneuploidy should be used as a determinant of the extent of operation for papillary thyroid carcinoma.