Serum Anti-p53 Antibody Can Serve as a Predictive Marker for Histological Grade of Intraductal Papillary Mucinous Neoplasms of the Pancreas.

OBJECTIVE The aim of the study was to clarify the diagnostic impact of measuring serum anti-p53 antibody (S-p53Ab) in predicting the histological grades of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. METHODS We compared the measured values and positive prevalence of S-p53Ab across the different histological grades of 111 resected IPMN cases. We also evaluated the TP53 alterations using immunohistochemistry and next-generation sequencing. RESULTS Serum anti-p53 antibody were detected in 6 of 111 cases, all of their histological grades were high-grade dysplasia (HGD) and invasive carcinoma (INV). Positive prevalence of S-p53Ab was higher in cases with INV (4/35 cases, 11.4%) than those with HGD (2/38 cases, 5.3%), whereas S-p53Abs were undetectable in cases with low-grade dysplasia. Measured S-p53Ab values were not correlated with either carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9 (CA 19-9). In 4 of 6 S-p53Ab-positive cases, the TP53 alterations-somatic pathogenic mutations or aberrant immunoreactivity-were identified in their IPMN lesions. A combination assay of S-p53Ab, CEA, and CA 19-9 revealed a 38.4% sensitivity and 81.6% specificity for predicting HGD/INV. CONCLUSIONS Serum anti-p53 antibody can serve as a surrogate marker for TP53 alterations and help predict the presence of HGD/INV in cases with IPMN, in combination with CEA and CA 19-9.