Increased mortality in patients with differentiated thyroid cancer associated with graves' disease.Pellegriti G, Mannarino C, Russo M, Terranova R, Marturano I, Vigneri R, Belfiore A. J Clin Endocrinol Metab. 2013 Mar;98(3):1014-21
We previously reported that differentiated thyroid cancer (DTC) has higher aggressiveness and poorer prognosis in patients with Graves' disease (GD) than DTC in euthyroid control patients, but this is debated. The previously described cohorts of nonoccult DTCs occurring in either patients with GD (DTC-GD, n = 21) or matched euthyroid DTC control patients (n = 70) were compared again after a longer follow-up (50-363.6 months; median, 165.6 months) to compare the major clinical endpoints of persistent/recurrent disease and overall survival. All patients had undergone total thyroidectomy and were followed up according to a standardized protocol. Persistent/recurrent disease was more frequent in DTC-GD patients than in control patients (P = .0119). Disease-specific mortality was also significantly higher in DTC-GD patients (6 of 21, 28.6%) than in euthyroid control patients (2 of 70, 2.9%) (P = .0001). At the last visit, the percentage of disease-free patients was 57.1% (12 of 21) in the DTC-GD group vs 87.1% (61 of 70) in the control group (P = .0025).
Nonoccult DTCs occurring in patients with GD cause increased disease-specific mortality compared with DTCs in matched euthyroid control patients. These findings emphasize the need for early diagnosis and aggressive treatment of nonoccult DTCs in patients with GD.

COMMENT- While unlikely to permanently settle the issue, this is good evidence that GD worsens the outlook, possibly via the contribution of thyroid stimulating antibodies,  L De Groot,  MD