The frequency of SATB2 and CDX2 expression in metastatic mucinous tumors of ovarian and colonic origin

Abstract

Introduction: Metastatic mucinous tumors present a unique diagnostic challenge for surgical pathologists due to their varied origins and potential diagnostic difficulties. Objectives: This study aimed to determine the frequency of SATB2 and CDX2 expression in metastatic mucinous tumors of ovarian and colonic origin. Materials and Methods: Paraffin blocks (n = 40) containing mucinous tumors of ovarian or colonic origin were collected from two educational hospitals affiliated with Isfahan University of Medical Sciences between 2009 and 2019. Prepared slides were stained for special AT-rich sequence-binding protein 2 (SATB2) and caudal type homeobox 2 (CDX2). The nuclear intensity of SATB2 or CDX2 staining was graded as follows: "0" for negative, "1+" for weak, "2+" for moderate, and "3+" for strong. The percentage of tumor staining was graded based on three categories: the majority of tumor staining (>50%) as "2", minority of tumor staining (5-49%) as "1", and negative staining (<5%) as "0". The final histologic score (H-score) was calculated by combining these intensity and percentage scores. Results: Both SATB2 and CDX2 were more frequently expressed in metastatic mucinous tumors of colonic origin compared to ovarian origin (65.5% versus 36.4% and 93.1% versus 72.7%, respectively), but the difference was not statistically significant. No significant differences were observed between metastatic mucinous tumors of colonic and ovarian origin regarding SATB2 and CDX2 nuclear intensity, percentage of tumor staining, and H-score. The sensitivity and specificity of CDX2 for differentiating between colonic and ovarian origin were 93.10% and 27.27%, respectively. The corresponding diagnostic values for SATB2 were 65.52% and 63.64%, in sequence. Conclusion: Neither of the two biomarkers, nor their combinations, demonstrated acceptable diagnostic values for distinguishing between metastatic mucinous tumors of ovarian and colonic origin.