Relationship of sodium/iodide symporter expression with I131 whole body scan uptake between primary and metastatic lymph node papillary thyroid carcinomas

Abstract

The aim of the present study was to evaluate total and membranous Na+/I- symporter (NIS) expressions in papillary thyroid carcinoma (PTC) tissue, correlation of NIS expression between primary and metastatic lymph node (LN) PTC tissues, and relationship of NIS expression with I131 whole body scan (WBS) uptake between primary and metastatic LN PTC tissues by analyzing 17 pairs of primary and metastatic LN PTC tissues. Staining positivity was calculated, and staining intensity was graded as negative (0), weak (1+), moderate (2+) and strong (3+). In primary PTC tissues, positivities and intensities of normal cells were higher than those of carcinoma cells but had no correlation with those in matched metastatic LN PTC tissues. In classic type, positivities, intensities and membranous intensities (mIS) were correlated between primary and matched metastatic LN PTC tissues. In patients aged younger than 45 yr, positivities and intensities in primary PTC tissues had correlation with those in matched metastatic LN PTC tissues. Positivities, intensities, mIS and pathological subtype of carcinoma cells in primary PTC tissues were not correlated with age, tumor size, TNM stage, MACIS score and thyroglobulin (Tg) levels at the time of I131 WBS. Sensitivity, specificity, as well as positive and negative predicted values of mIS in patients with I131 WBS uptake were 69.2, 75, 90 and 42.9% in primary PTC tissues, and 92.3, 100, 100 and 80% in metastatic LN PTC tissues. The results of mIS taken either as positive or negative were correlated with those of I131 WBS after controlling for age. Our results demonstrate that PTC tissues have altered total and membranous NIS expressions, suggesting that NIS expression in primary PTC tissues may predict NIS expression and I131 WBS uptake in matched metastatic LN PTC tissues.

NIS expression in thyroid tumors, relation with prognosis clinicopathological and molecular features

“…These observations suggest that in thyroid carcinomas, besides transcription regulation, NIS expression appears to be modulated by post-transcriptional events. Therefore, studies of NIS expression by immunohistochemistry (IHC) ( 1 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ), may be, theoretically, more informative since they ‘grab’ NIS a step forward in its biological processing and allow the evaluation of the localization of NIS in the basolateral plasma membrane of follicular cells (the functional transporter).…”

Use of sodium iodide symporter expression in differentiated thyroid carcinomas

“…12 Some reports suggested that NIS expression in primary papillary thyroid carcinoma (PTC) tissues could predict NIS expression and radioiodine uptake in matched metastases. [13][14][15] However, the report saying that the defective targeting of NIS and the consequent reduced level of iodine uptake in thyroid cancer are mainly caused by low NIS expression and not by the intracellular localization of overexpressed NIS has raised concerns on the significance of NIS protein expression, as demonstrated by different NIS antibodies. 16 In fact, we recently described a classic papillary thyroid carcinoma (CPTC) patient with positive immunohistochemical staining for NIS but no response to radioiodine therapy.…”

A Proposition for the Use of Radioiodine in WDTC Management

“…For patients with primary tumors smaller than 5 mm, recurrences appear in about 1% (7). In follow-up, cervical metastases were discovered more frequently if, at the time of the original operation, the lymph nodes contained carcinoma (8,9). Hay et al found that postoperative 131 I treatments were not followed by statistically fewer nodal recurrences (8), but Chow et al reported that, after ablation, new cervical disease was statistically less common (9).…”

“…In follow-up, cervical metastases were discovered more frequently if, at the time of the original operation, the lymph nodes contained carcinoma (8,9). Hay et al found that postoperative 131 I treatments were not followed by statistically fewer nodal recurrences (8), but Chow et al reported that, after ablation, new cervical disease was statistically less common (9). However, overall, recurrences in the absence of ablation therapy were seen in few patients: only 11 (8) and 4 (9).…”

“…With the introduction of 18 F-deoxyglucose and 124 I metabolic PET/ CT, and new drugs that target precise metastatic pathways (6-8), we must shift from a macroscopic definition of thyroid cancers toward their microscopic, metabolic, histologic, and genetic characterization. With regard to this last point, we would stress that most cases of thyroid cancer express the sodium iodide symporter (9). As with other membranous receptors in other cancers, it would be logical to take into account immunohistologically assessed sodium iodide symporter expression in managing thyroid carcinoma and in deciding on treatment with high-activity 131 I.…”