Reply to Increased cancer incidence after radioiodine treatment for hyperthyroidism

✍ Scribed by Saara Metso; Jorma Salmi; Pia Jaatinen

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 35 KB
• Volume: 112
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/cncr.23126

✦ Synopsis

Increased Cancer Incidence After Radioiodine Treatment for Hyperthyroidism M etso et al. 1,2 recently reported increased cancer mortality in hyperthyroid patients treated by radioiodine. Major limitations of those works, as lacking of hyperthyroid controls, were correctly discussed by the authors. However, in our opinion the evaluation of administered activity and associated mortality risk should be biased. In fact, the analysis was performed on 3 subgroups (ie, patients treated by 55-258 MBq, 259-369 MBq, and 370-2664 MBq, respectively) and increased mortality was observed only in the latter. Because 1) mean administered activity was 305 MBq, 2) only 24% of patients received more than 370 MBq, and 3) the 370-2664 MBq is a very wide range, more detailed analysis of the activity received by patients who died after radioiodine is needed. In fact, activities more than 600-740 MBq are not usually administered to treat hyperthyroidism and Metso et al.