The value of DNA content in predicting the prognosis of thyroid carcinoma in an endemic iodine deficiency region

DNA content of tumour was found to correlate with various prognostic factor s and survival, especially in well differentiated thyroid carcinoma. The ai m of this investigation was to evaluate the correlation between the DNA plo idy and the prognosis as well as the survival in thyroid carcinoma in our c ountry, being an endemic iodine deficiency region. DNA flowcytometry was performed on paraffin embedded archival tissue blocs of 74 patients with thyroid carcinoma (70 well differentiated, 3 anaplastic and Hurthle cell carcinoma) and 12 patients with multinodular goitre. DNA ploidy was defined as diploidy or aneuploidy. Aneuploidy was detected in 5 (6.8%) patients with thyroid carcinoma (3 anap lastic, papillary and 1 Hurthle cell carcinoma). Aneuploidy was significant ly more frequent in patients with anaplastic carcinoma (n: 3/3, 100%) compa red to well differentiated thyroid carcinoma (n: 1/70, 1.4%) (p < 0.0001). Aneuploid DNA content significantly correlated with advanced age (p < 0.01) , large tumour size (p < 0.001), and low survival (p < 0.01). Mean survival period of patients with anaplastic carcinoma in whom aneuploi dy was frequently encountered, was shorter compared to patients with diploi d well differentiated tumours (p < 0.01). In conclusion, although anaplastic and follicular carcinoma are more freque ntly diagnosed in endemic areas, the rate on aneuploidy was found to be low er in thyroid carcinoma in our country compared to data reported to nonende mic areas. As the prognostic predictive value of DNA ploidy is reliable in well differentiated thyroid carcinoma, DNA measurement of FNA biopsy may in fluence the extent of surgery. Thyroid carcinoma, other than well different iated types, require radical operations independent of the DNA content. How ever, adjunctive treatment methods may be used earlier postoperatively acco rding to quantitative DNA measurement.