Multicentre study comparing aggressive behaviour of familial non-medullary thyroid carcinoma and sporadic thyroid cancer

Background Familial non-medullary thyroid cancer represents about 5 per cent of all thyroid cancers of follicular cell origin. Whether familial non-medullary thyroid cancer is more aggressive than sporadic thyroid cancer is controversial. Methods Each patient with familial non-medullary thyroid cancer was matched with three controls for age, sex and tumour node metastasis (TNM) stage of disease. Possible prognostic factors were compared in relation to recurrence, metastases and mortality rate in both groups. Univariate analysis was performed using contingency table analysis and McNemar's χ2 test for paired measurements. Multivariate analysis was used to evaluate factors significant in univariate analysis. Results Forty-eight cases (ten men) and 144 matched controls (30 men) were analysed with a mean follow-up of 102 and 94 months respectively. The mean age was 39 years for cases and 46 years for controls. Some 29 per cent of the cases and 12 per cent of the controls had history of prior or coexistent benign thyroid disease (P < 0·05). Ninety-four per cent of cases and 90 per cent of controls had papillary cancers; the remainder were Hurthle cell cancers. Based on TNM staging, there were 66 per cent stage I, 21 per cent stage II and 13 per cent stage III tumours in the familial non-medullary thyroid cancer group; the distribution was similar in the control group. Modified radical neck dissection was performed in 42 per cent of cases and 22 per cent of controls. Multifocal or bilateral disease was seen in 75 per cent of cases and 41 per cent of controls (P < 0·05); 35 per cent of cases and 16 per cent of controls had at least one recurrence (P < 0·05). Ten per cent of cases and 2 per cent of controls developed distant metastases (P < 0·05). Six per cent of cases but no controls died from thyroid cancer (P < 0·05). In patients with familial non-medullary thyroid cancer aged over 45 years (n = 14), distant metastases affected four, of whom three died. In multivariate analysis, age was the only significant variable that affected the disease outcome (P < 0·01). Conclusion Familial non-medullary thyroid cancer is more aggressive than sporadic thyroid cancer and is associated with increased recurrence, metastasis and death, especially in patients over 45 years of age. © 2000 British Journal of Surgery Society Ltd