Thyroid carcinoma after radioactive iodine therapy for Graves' disease

Abstract

Although the causal relation between radioactive iodine therapy (RIT) for Graves' disease and the subsequent occurrence of thyroid carcinoma is not definite, surgeons may be faced with the treatment of such patients. We studied the clinicopathologic features of patients with thyroid carcinoma following RIT for Graves' disease. From January 1983 to December 1991, 11 patients with thyroid carcinoma occurring 1 year or more after RIT for Graves' disease underwent surgery at Ito Hospital. These 11 patients accounted for 0.51% of 2146 surgical cases of thyroid carcinoma and 0.17% of 6419 RIT cases of Graves' disease during the period. They were all women, and their mean ages at RIT and surgery were 44.3 and 51.4 years, respectively. The administered dose of RI was 222.1 MBq and the absorbed dose 45.3 Gy on average. Total thyroidectomy was performed in two patients, subtotal thyroidectomy in three, and lobectomy in six. Bilateral modified neck dissection (MND) was added in two patients, and ipsilateral MND in seven. Histology revealed 10 papillary and 1 follicular carcinoma. The mean diameter of the tumor was 18.5 mm. Intraglandular dissemination of the tumor was noted in only one case and solid growth pattern in two. Nodal metastasis was disclosed in six cases, but in five of them only one node was involved. The present study indicated that thyroid carcinoma occurring after RIT for Graves' disease is not an aggressive variety, and thyroid lobectomy with ipsilateral MND would be sufficient as surgical treatment for such patients.

Ultrasonographic screening for detection of thyroid cancer in patients with Graves’ disease

“…In this prospective study, our aim was to determine prevalence of thyroid nodule/cancer in Graves’ patients, and to evaluate the clinical value of USG screening for detection of thyroid cancers in those patients. As radio‐iodine treatment or radiation to head/neck area may change the prevalence or the behaviour of thyroid cancers (Ozaki et al ., 1994; Fuzikawa et al ., 1998; Hall & Holm, 1998; Damber et al ., 2002; Dickman et al ., 2003), we excluded patients who had prior radio‐iodine therapy or radiation to head/neck area. Among 261 eligible patients, 94% underwent thyroid USG for detection of nodules, so bias due to selection of patients seems to be negligible.…”

Thyroid Cancer in Patients with Hyperthyroidism

“…Ozaki et al reported a 0.17 % thyroid cancer incidence in Graves' patients treated with radioactive iodine vs. 2.5 % in Graves' patients treated with surgery [ 58 ] . In a study by Behar et al, 303 patients received RAI therapy for Graves' disease and only one (0.3 %) subsequently developed thyroid carcinoma [ 40 ] .…”

Cancer risk after medical exposure to radioactive iodine in benign thyroid diseases: a meta-analysis

“…1). Seventeen of these were then excluded because they were not found to address 131 I use (nZ3;Berlin & Wasserman 1976, Hoffman et al 1984, Mellemgaard et al 1998, did not report effect sizes (RR or SIR; Munoz et al 1978), were descriptive studies (nZ7; Pochin 1960, Dobyns et al 1974, Freitas et al 1979, Spencer et al 1983, Ozaki et al 1994, Angusti et al 2000, Listewnik et al 2010 or had overlapping datasets (nZ6; Saenger et al 1968, Holm et al 1980, Hall & Holm 1995a,b, Hall et al 1996. Seven studies were finally selected for this meta-analysis (Hoffman et al 1982, Goldman et al 1988, Holm et al 1991, Franklyn et al 1999, Hahn et al 2001, Dickman et al 2003, Metso et al 2007).…”