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.