RESUMO
Signet ring cell carcinomas of the gastrointestinal (GI) tract are clinically aggressive neoplasms with frequent intra-abdominal metastases at initial presentation. Currently available immunohistochemistry (IHC) markers cannot distinguish signet ring cell carcinomas of the lower GI tract and upper GI tract, suggesting the need for more specific diagnostic markers. SATB2 is a novel, sensitive marker for colorectal carcinoma. We hypothesized that SATB2 IHC can reliably identify primary and metastatic signet ring cell carcinomas of lower GI tract origin. SATB2 and CDX2 IHC was performed on 159 primary (n=93) and metastatic (n=66) signet ring cell carcinomas of GI tract origin and 13 metastatic breast carcinomas with signet ring cell features. Positive SATB2 expression (SATB2) was identified in 82% (27/33) of appendiceal, 88% (43/49) of colorectal, 13% (7/54) of gastric, and 35% (8/23) of esophageal/esophagogastric junction signet ring cell carcinomas. Primary and metastatic signet ring cell carcinomas of lower GI tract origin were more frequently SATB2 than those from upper GI tract (70/82, 85% vs. 15/77, 19%, P<0.01). Compared with CDX2, SATB2 and dual-positive staining for SATB2 and CDX2 both had higher specificities for signet ring cell carcinomas from the lower GI tract (81% vs. 49% and 86% vs. 49%, respectively, P<0.01 for both). Two (15%) metastatic breast carcinoma were SATB2, but all 13 demonstrated negative CDX2 staining. In summary, our results show SATB2 is a relatively specific immunohistochemistry marker for both metastatic and primary signet ring cell carcinomas of lower GI tract origin.
Assuntos
Biomarcadores Tumorais/análise , Fator de Transcrição CDX2/análise , Carcinoma de Células em Anel de Sinete/química , Neoplasias Gastrointestinais/química , Proteínas de Ligação à Região de Interação com a Matriz/análise , Fatores de Transcrição/análise , Neoplasias da Mama/química , Neoplasias da Mama/patologia , Carcinoma de Células em Anel de Sinete/secundário , Bases de Dados Factuais , Diagnóstico Diferencial , Feminino , Neoplasias Gastrointestinais/secundário , Humanos , Imuno-Histoquímica , Masculino , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
The special AT-rich sequence binding protein (SATB2) has been reported to be a specific immunohistochemical marker for colorectal carcinoma; however, correlation of SATB2 expression with molecular alterations commonly assessed in colorectal carcinoma has not been performed. We examined the immunohistochemical expression of SATB2 in 586 adenocarcinomas of the gastrointestinal (GI) tract and pancreas to assess its utility in diagnosis and analyze the clinicopathologic and molecular characteristics of colorectal carcinoma stratified by SATB2 expression. SATB2 and CDX2 expression were evaluated in 266 adenocarcinomas of lower GI tract origin (246 colorectal and 20 appendiceal mucinous), 208 adenocarcinomas of upper GI tract and small intestinal origin (74 esophagus/esophagogastric junction, 103 stomach, 20 duodenal, and 11 jejunoileal), and 112 pancreatic ductal adenocarcinomas. SATB2 expression was more frequently identified in adenocarcinomas of lower GI tract origin (222/266, 83%) compared with upper GI tract, small intestinal, or pancreatic origin (26/320, 8%) (P<0.001). Compared with CDX2 alone, dual positive expression for SATB2 and CDX2 (SATB2/CDX2) has a significantly higher specificity for adenocarcinoma of lower GI tract origin (94% vs. 57%, P<0.001). In colorectal carcinoma, loss of SATB2 expression was more frequently observed in DNA mismatch repair (MMR) protein deficient tumors (31%) compared with MMR protein proficient tumors (13%) (P<0.01). A BRAF V600E mutation was more frequently identified in colorectal carcinomas with loss of SATB2 expression compared with those with positive SATB2 expression (29% vs. 3%) (P<0.001). In summary, SATB2 expression is a relatively specific marker of lower GI tract origin; however, loss of SATB2 expression is more commonly seen in colorectal carcinoma with MMR protein deficiency and BRAF mutation.