[1529] Immunohistochemical Assessment of DCBLD2 and PDZD3 Expression in Pancreatic Ductal Adenocarcinoma.

Purva Gopal, Toby C Cornish, Nipun B Merchant, Ralph H Hruban, Chanjuan Shi. Vanderbilt University Medical Center, Nashville, TN; Johns Hopkins University, Baltimore, MD

Background: DCBLD2 is a tyrosine-phosphorylation target of epidermal growth factor (EGF) signaling and is believed to play a role in cancer cell proliferation and metastasis in gastric and lung carcinomas. PDZD3 is a regulatory protein for guanylyl cyclase C and has been associated with colon cancer metastasis. The aim of this study is to correlate DCBLD2 and PDZD3 expression in pancreatic ductal adenocarcinoma (PDA) with prognosis.
Design: Tissue microarrays composed of PDAs from 36 patients and corresponding normal pancreatic tissue were used in this study and were immunohistochemically labeled with antibodies to DCBLD2 and PDZD3. Expression of DCBLD2 and PDZD3 in PDA was correlated with lymphovascular invasion (LVI), perineural invasion (PNI), tumor stage (TS) at diagnosis, and overall survival (OS).
Results: Twenty-one of 36 (58%) PDAs expressed DCBLD2 as compared to 1 of 36 (0.03%) normal pancreatic ducts (p=0.0001). Carcinomas which expressed DCBLD2 had abundant intracytoplasmic mucin. There was no significant association between DCBLD2 expression and LVI, PNI and TS (p>0.05). Mean overall survival was higher for patients with PDAs that expressed DCBLD2 (22 months, SEM=3.342) as compared to those who did not express DCBLD2 (14 months, SEM=4.087) however this difference was not statistically significant, probably due to small sample size. Eighteen of 34 (53%) PDAs expressed PDZD3 compared to 10 of 33 (30%) normal pancreatic ducts (p=0.08). There was no association between expression of PDZD3 and LVI, PNI, TS, or overall survival (p>0.05).
Conclusions: More than 50% of PDAs express DCBLD2 and PDZD3. The expression of these genes did not correlate with poor prognostic indicators in this sample set. Expression of DCBLD2 was specific for PDA, and this expression trended towards a better overall survival. These findings suggest that further studies on whether DCBLD2 could serve as a potential biomarker and therapeutic target for patients with PDA may be warranted.
Category: Liver & Pancreas

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 207, Tuesday Afternoon


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