[1869] Loss of PTEN Expression Is Associated with Poor Prognosis in Patients with Ampullary Adenocarcinoma

Stuti Shroff, Michael Overman, Asif Rashid, Hua Wang, Rachna Shroff, Stanley Hamilton, Matthew H Katz, Jeffrey E Lee, Henry F Gomez, James L Abbruzzese, Jason B Fleming, Huamin Wang. The University of Texas MD Anderson Cancer Center, Houston, TX

Background: PTEN is one of the most frequently inactivated tumor suppressor genes in the development of many cancers such as glioblastomas, endometrial, prostate, lung and breast cancer. However, the expression of PTEN and its significance in ampullary adenocarcinoma (AA) has not been studied.
Design: We constructed tissue microarrays using archival tissue from 113 patients with AA who underwent pancreaticoduodenectomy at our institution. There were 69 males and 44 females with age ranging from 28 to 87 years (median: 64 years). Each tumor was sampled in duplicate with a 1.0 mm punch from representative areas of the tumor. PTEN expression was evaluated by immunohistochemistry and scored semiquantitatively based on the staining intensity and the percentage of positive tumor cells. PTEN expression was categorized as PTEN-negative (negative or staining in <5% of tumor cells) or PTEN-positive (positive staining in ≥5% tumor cells). Staining results were correlated with clinicopathologic features and survival.
Results: Thirty of 113 (26.5%) cases were PTEN-negative. Loss of PTEN expression in AA correlated with CDX2 expression (p=0.03), higher tumor (pT) stage (p=0.005), lymph node metastasis (p=0.010), and advanced AJCC stage (p=0.017). Patients whose tumors were PTEN-negative had shorter overall survival (mean: 113.9±16.3 months) than those whose tumors were PTEN-positive (167.6 ± 10.5 months, p = 0.04). No correlation between PTEN expression with other clinicopathologic factors were observed (p>0.05). In multivariate analysis, PTEN expression was a prognostic factor for overall survival independent of pT stage, lymph node status, differentiation and resection margin status.
Conclusions: Loss of PTEN expression is associated with poor overall survival in patients with AA. PTEN expression may be used as a prognostic marker for patients with resected AA.
Category: Pancreas

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 255, Wednesday Morning


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