The Utility of Immunohistochemical Staining with CEA, CA19-9, P53, and MIB to Improve the Diagnostic Yield of Endoscopic Ultrasonography Guided Fine Needle Pancreatic Aspirates

The Utility of Immunohistochemical Staining with CEA, CA19-9, P53, and MIB to Improve the Diagnostic Yield of Endoscopic Ultrasonography Guided Fine Needle Pancreatic Aspirates Alia Dadabhai, Stephen L. Chen, Steve Tsai, Rose Venegas, Samuel French, Sartaj Arora, Mehrdad Vasdoghi, Ben Garrett, David Chung, Shahid H. Sial, Viktor Eysselein In a study of 100 specimens obtained by EUS-FNA, P53, MIB, CA19-9 and CEA were used in an analysis of 71 samples to determine if tumor markers increased the diagnostic yield of cytologically atypical or benign samples. A prospective analysis was performed of all patients undergoing EUS-FNA of pancreatic lesions. Methods: Four antibodies were used for immunohistochemical labeling: p53 (DO-7)Zymed and MIB (Ki-67)Zymed, CEA (monoclonal ab) – Zymed and CA19-9. Cytology smears and cell blocks were reviewed by two cytopathologists who were blinded to the tumor markers and the final diagnoses. The specimens were categorized as tumor marker positive if there was O 5% nuclear staining by MIB ab, and if there was positive labeling for p53, CEA and CA19-9 in one or more cells. Follow-up data for each patient was determined by surgical pathology or clinical follow-up. Results: In 100 consecutive pancreatic EUS-FNAs, an adequate amount of aspirate was obtained for cytology smear in 89% (89/100) of patients, and for immunohistochemical labeling in 71% (71/100) of specimens. The cytology smears showed 24 benign lesions, 23 malignant lesions, 24 with atypical cells, with 11 hypocellular aspirates. Of the adequate cytology smears were 34% (24/71) were atypical. 58% of the atypical aspirates (14/24), 29% (7/24) of the benign aspirates, and 100% of the malignant smears, were malignant on clinical or surgical follow-up. Combined tumor markers and cytology increased the sensitivity of aspirates to 89% and increased the number of patients detected with malignant disease from 23 to 39 out of the total 44 patients with cancer. Sensitivity of cytologic diagnosis alone was 52%. This sensitivity increased to 89% when combined tumor markers were used. The specificities of the individual tumor markers ranged from 80-100%. Conclusions: The addition of immunohistochemical labeling with p53, MIB, CEA and CA19-9 to cytology enhances the diagnostic yield and sensitivity for finding pancreatic malignancy by EUS-FNA by 31%. Immunohistochemical labeling may be useful to detect well-differentiated tumors when diagnosis by cytology is nonconclusive or benign and may reduce the need for repeat EUS-FNA.