Epidermal growth factor receptor overexpression in resected pancreatic cancer.

Authors

Amit Mahipal

Amit Mahipal

Thomas Jefferson University

Amit Mahipal , Brian Carr

Organizations

Thomas Jefferson University, Kimmel Cancer Center of Thomas Jefferson University

Research Funding

No funding sources reported

Background: The effect of overexpression of epidermal growth factor receptor (EGFR) in pancreatic carcinoma is uncertain. In this study, we examine the association between EGFR overexpression (membrane and cytoplasmic) and histopathologic features and clinical outcomes in patients post resection. Methods: Seventy three patients underwent curative resection for pancreatic cancer from 4/08 to 4/10. Tumor EGFR expression was determined immunohistochemically using EGFR pharmDxTM kit. Cytoplasmic overexpression was considered positive if EGFR expression was seen in the cytoplasm in ≥10% of cells. Cell membrane staining scores were assigned: 0 (no membrane staining), 1+ (incomplete membrane staining in ≥ 10% of cells, 2+ (complete weak/moderate membrane staining in ≥ 10% of cells) and 3+ (complete heavy staining in ≥ 10% of cells). A score of 2+ and 3+ were considered as membrane overexpression. Comparisons between EGFR overexpression and clinicopathologic features were assessed by chi-square test with p-value < 0.05 as statistically significant. Proportional hazard regression was used to estimate progression free survival and overall survival. Results: Out of 73 patients, 43 (59%) and 50 (68%) patients had membrane and cytoplasmic EGFR overexpression respectively. AJCC stages were: stage I: 8, stage II: 63, stage III: 1 and stage IV: 1 patient. There was statistically significant correlation between cell membrane EGFR overexpression and lymph node positivity (p=0.04). Membrane EGFR overexpression was not significantly associated with local invasion, margin positivity, vascular invasion, perineural invasion, histologic grade or stage. Cytoplasmic EFGR overexpression was significantly associated with margin positivity (p=0.01) only. The hazard ratios (95% CI) for PFS and OS in patients with membrane EGFR overexpression was 1.37 (0.72-2.60) and 1.27 (0.62-2.61) respectively. The corresponding values for patients with cytoplasmic overexpression were 1.65 (0.80-3.37) and 1.25 (0.58-2.71) respectively. Conclusions: Membrane EGFR overexpression was associated with lymph node status and cytoplasmic EFGR overexpression with margin positivity. There was no association of EFGR expression and clinical outcomes.

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Abstract Details

Meeting

2011 Gastrointestinal Cancers Symposium

Session Type

Poster Session

Session Title

General Poster Session B

Track

Cancers of the Pancreas, Small Bowel, and Hepatobiliary Tract

Sub Track

Multidisciplinary Treatment

Citation

J Clin Oncol 29: 2011 (suppl 4; abstr 317)

Abstract #

317

Poster Bd #

A165

Abstract Disclosures