The incidence of familial nonmedullary thyroid cancer in a large case series.

PURPOSES OF THE STUDY

In contrast to familial medullary carcinoma, familial nonmedullary thyroid carcinoma (FNMTC) is less frequent and has been less investigated. The aim of this study was to determine the frequency of FNMTC and analyse the main demographic and clinical characteristics of the patients.

MATERIAL AND METHODS

Data on 1411 patients surgically treated for nonmedullary thyroid carcinoma, in the Center for Endocrine Surgery in Belgrade, from 1995 to 2006 were analysed. The possible presence of malignant tumours of the thyroid gland was investigated in their closest relatives in order to identify cases of FNMTC. Only data on first-degree relatives (parents and children) and second-degree relatives (grandparents, grandchildren and siblings) were taken into account in the analysis.

RESULTS

Thirteen patients (11 females and 2 males) (0.92% of those with nonmedullary carcinoma of the thyroid gland) had a familial form of the disease. In five families two members had a tumour, and in one family three members. In five out of six families it was a papillary carcinoma and in one family a follicular carcinoma. Patient age varied from 20 to 79 years, with a mean age of 40 years. The tumour size ranged from 5 to 60 mm (mean 25 mm). In two of the thirteen cases the tumour penetrated the capsule of the thyroid gland. In four cases the tumour was multicentric and bilateral, and in a further two metastases were present in regional lymph nodes. During the follow-up period, which lasted from 2 to 12 years (mean 8.5 years), two relapses were detected.

CONCLUSION

Familial nonmedullary carcinoma of the thyroid gland occurs very rarely.