[574] Anti-Tn and Anti-Sialyl-Tn Antibodies in the Evaluation of Thyroid Neoplasms and Normal Thyroid Tissue

Harold C Sullivan, Sean R Stowell, Richard D Cummings, Brian C Quigley, Momin T Siddiqui, Cynthia Cohen. Emory University, Atlanta, GA

Background: Investigators have long attempted to identify cancer-associated antigens. Consequently, antibodies have been created to aid in diagnosis. Recent studies suggest that alterations in post-translational modifications to Tn and sialyl-Tn (sTn) carbohydrates may occur following mutations in Cosmc, a key regulator of these modifications. These aberrant modifications could serve as unique targets of neoplastic disease. Tn, normally immunologically inaccessible in adult human tissue, has been shown to be expressed in endometrial, breast, ovarian, lung, colon, pancreatic, and urothelial carcinomas. The purpose of this study is to determine Tn and sTn expression in neoplastic and nonneoplastic thyroid tissue, in which determination of neoplastic vs. nonneoplastic is challenging, especially in cytology and surgical specimens where the differential includes follicular adenoma and carcinoma.
Design: Tissue microarrays (TMAs) of thyroid neoplasms and adjacent normal thyroid were created. Neoplasms included papillary thyroid carcinoma, follicular carcinoma, follicular adenoma, anaplastic carcinoma, medullary carcinoma, Hurthle cell neoplasms, and multinodular goiters. TMAs were immunostained with Tn and sTn monoclonal antibodies identified by glycan microarray at Emory University. Expression for both antigens was cytoplasmic. An immunostain intensity of 2 (scale:0-3) and a percentage of positive-staining cells of >5% were considered positive.
Results: See table.

Tn and sTn Expression in Normal and Neoplastic Thyroid Tissue
Tissue type (no.)Tn positive no. (%)P-value*sTn Positive no. (%)P-value*
Normal (140)0 (0)N/A0 (0)N/A
Papillary thyroid carcinoma (94)3 (3)0.640 (0)N/A
Follicular carcinoma (52)0 (0)N/A0 (0)N/A
Follicular adenoma (8)0 (0)N/A0 (0)N/A
Anaplastic carcinoma (14)4 (29)<0.00010 (0)N/A
Medullary carcinoma (2)0 (0)N/A0 (0)N/A
Hurthle cell neoplasm (25)0 (0)N/A1 (4)0.151
Multinodular goiter (38)0 (0)N/A1 (3)0.212
* Tn and sTn expression compared between normal tissue and each respective neoplastic subtype. For neoplasms that did not express antigen, no p-value could be calculated.

Conclusions: While none of the normal thyroid tissue expressed Tn or sTn, neither did most of the neoplastic thyroid tissue. The notable exception is Tn expression in 29% of anaplastic thyroid carcinomas. Thus, although Tn and sTn expression may be of benefit in identifying and characterizing various other carcinomas, only in the thyroid anaplastic subset does Tn appear clinically promising, for diagnosis and therapy.
Category: Endocrine

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 62, Wednesday Afternoon


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