Tumor-associated glycoprotein distribution detected by monoclonal antibody B72.3 in salivary neoplasia

Abstract

The expression of tumor‐associated glycoprotein (TAG‐72), an oncofetal mucin‐like tumor‐associated glycoprotein derived from membrane‐enriched fractions of metastatyic breast carcinoma, has been detected by monoclonal antibody (MoAb) B72.3 in adenocarcinomas of breast, colon, lung, endometrium, pancreas, and ovary. The authors reported the scope of TAG‐72 expression detected by MoAb B72.3 in salivary neoplasia. They examined 96 salivary lesions (53 malignant and 37 benign primary tumors, 2 metastatic carcinomas, and 4 other benign lesions) and 17 normal tissues from parotid glands and found: diffuse TAG‐72 expression in 29 of 55 (53%) malignant tumors and 6 of 36 (17%) benign tumors and in no normal tissue; focal TAG‐72 expression in 10 of 55 (17%) malignant salivary tumors, 10 of 37 (25%) benign salivary tumors (all benign mixed tumors), and 1 of 17 (6%) histologically normal parotid gland ducts. Any expression of TAG‐72, whether diffuse or focal, was found to have a 71% sensitivity for detecting salivary malignant tumors, but an unacceptably low specificity for malignant lesions (57%). Alternatively, if only diffuse TAG‐72 expression was regarded as indicative of malignancy, the specificity of diffuse TAG‐72 expression was 86%, but sensitivity of detection decreased to 53%. The authors studied a subset of benign and malignant mixed tumors (BMT and MMT) and found that 12 of 15 (80%) MMT diffusely and strongly expressed TAG‐72, 2 of 15 MMT (13%) expressed TAG‐72 focally, and 1 MMT (7%) was nonreactive. By contrast, most BMT did not express TAG‐72; only sparse, focal TAG‐72 expression was seen in 10 of 27 (37%) BMT. If diffuse TAG‐72 expression is considered indicative of malignancy, its sensitivity and specificity for malignant mixed tumors is 80% and 100%, respectively. The authors suggest that diffuse TAG‐72 expression may resolve conflicts in determining whether or not a mixed tumor is malignant.

A Fas Ligand (FasL)-Fused Humanized Antibody Against Tumor-Associated Glycoprotein 72 Selectively Exhibits the Cytotoxic Effect Against Oral Cancer Cells with a Low FasL/Fas Ratio

“…TAG-72 was also found to be expressed by oral cancer cells (18, 21), indicating that hcc49scFv-FasL, possibly through binding to TAG-72, induced FasL-mediated cell death (Fig. 3A).…”

Tumor‐Associated Glycoprotein (TAG‐72) in Chronic Submandibular Sialadenitis and Normal Minor Salivary Glands Defined by Monoclonal Antibody B72.3

“…It was proposed that the Mab B72.3 can be used to define TAG‐72 expression in many adenocarcinomas and may serve as an adjunctive tool for the diagnosis and histologic typing of malignant cells in fine‐needle aspiration biopsy specimens 4 . Brandwein et al 10 examined many tumors of salivary glands using the Mab B72.3 and found diffuse expression of TAG‐72 in mucoepidermoid carcinoma, squamous carcinoma, Wharthin's tumor and papillary cystadenoma. They suggested that as the diffuse expression of TAG‐72 does not occur only in malignant tumors, the TAG‐72 expression in fineneedle aspiration biopsies must be interpreted with caution to serve as a diagnostic aid.…”

“…TAG‐72 expression was categorized as diffuse, focal, or negative according to Brandwein et al 10 Diffuse pattern of staining was defined as 1 or more low‐power fields (10 ×) of positive cells. Focal pattern of staining was defined as a few positive cells or groups of cells seen at high‐power magnification (40 ×).…”

“…The expression of TAG‐72 has been studied in many salivary gland tumors, in normal parotid gland, and in two cases of chronic submandibular sialadenitis 9‐11 …”

Expression of the Adenocarcinoma‐Related Antigen Recognized by Monoclonal Antibody 44‐3A6 in Salivary Gland Neoplasias

“…[5][6][7] In select cases the immunophenotype of the neoplasm may be extremely useful in determining the correct diagnosis and predicting prognosis. 8,9 Currently, work is under way to clarify the pathogenesis of these tumors, to identify factors that modulate the direction and extent of differentiation, and to predict their clinical behavior and/or response to treatment. Developments in monoclonal antibody (Mab) technology have offered an opportunity to expand our knowledge of the cellular and subcellular events that produce human disease.…”