Purpose: Approximately 5% of differentiated thyroid carcinomas are of familial origin. These familial nonmedullary thyroid carcinomas (FNMTC) have an increased risk of multifocal disease and lymph node involvement. Consequently, higher recurrence rates and decreased disease-specific survival rates are described. The best surgical approach is discussed controversially.
Patients and methods: A survey among the international members of the German Society of Endocrine Surgeons revealed 20 families with two or more first-degree relatives with FNMTC. The mean age of the 41 patients (30 female, 11 male) with FNMTC was 40.6 years (18-73 years).
Results: Total thyroidectomy was performed in 31 of 41 patients (76%). Ninety-five percent of the tumors were papillary carcinomas. Two of 41 patients had follicular carcinomas. Ten patients (24%) with papillary carcinomas were diagnosed with Hashimoto's thyroiditis. The mean tumor size was 1.45 cm. FNMTC was multifocal in 12 patients (29%). A systematic lymph node dissection was performed in 21 of 41 patients (51%). Lymph nodes metastases were found in seven of these 21 patients. Twenty-eight of the patients (68%) underwent postoperative radioiodine ablation. After a mean follow-up of 7.2 years, 39 patients (95%) were disease free. One patient developed local recurrence and lung metastases, 10 and 25 years, respectively, after initial diagnosis. Another patient died 2 years postoperatively from advanced metastatic disease.
Conclusions: FNMTC is associated with an early onset of small, mostly papillary thyroid carcinomas and an increased risk of multifocality and lymph node involvement. Total thyroidectomy and systematic neck dissection are recommended together with radioiodine ablation. Screening for first-degree relatives should start at age 18 years.