P-0172 - The vague entity of colorectal adenocarcinoma with mucinous activity: What's new?

Date 28 June 2014
Event World GI 2014
Session Poster Session
Topics Colon Cancer
Rectal Cancer
Pathology/Molecular Biology
Presenter Al-Rahman Foda Abd
Citation Annals of Oncology (2014) 25 (suppl_2): ii14-ii104. 10.1093/annonc/mdu165
Authors A. Foda Abd1, A. Abdel-Aziz1, A. El-Hawary1, A. Hosni2, K. Zalata1, A. Gado1
  • 1Pathology Department, Mansoura University, Mansoura/EG
  • 2Clinical Oncology and Nuclear Medicine Department, Mansoura University, Mansoura/EG

Abstract

Introduction

Colorectal adenocarcinoma with mucinous activity (AWMA) is a vague entity of ordinary adenocarcinoma that shows intra or extracellular mucin secretion less than 50% of the tumor. Few studies were concerned with the clinicopathological and molecular criteria of this entity, and whether it resembles ordinary adenocarcinoma without mucinous activity (OA) or mucoid adenocarcinoma with more than 50% of the tumor composed of mucin (MA). We aimed to compare AWMA, OA and MA regarding clinicopathological, histological parameters, survival, EGFR (as a marker of proliferation), MMP-13 (as a marker of invasion) and E-cadherin (as a marker of adhesion) expressions.

Methods

In this work, we studied tumor tissue specimens from 28 patients with AWMA, 47 patients with OA and 56 patients with MA, who underwent radical surgery from Jan 2007 to Jan 2012 at the Gastroenterology Centre, Mansoura University, Egypt. Their clinicohistopathological parameters and survival data were revised and analyzed using established statistical methodologies. High density manual tissue microarrays were constructed using modified mechanical pencil tips technique and immunohistochemistry for EGFR, MMP-13 and E-cadherin was done.

Results

AWMA was significantly associated with more perineural invasion (P = 0.027), lower EGFR (P = 0.007), and MMP-13 expressions (P= 0.005) than OA, with no difference in E-cadherin expression (P = 0.287). Conversely, only microscopic abscess formation was significantly more with AWMA than MA (P = 0.003) with no difference in EGFR (P = 0.876), MMP-13 (P = 0.287) and E-cadherin (P = 0.432) expression between both groups. However, AWMA showed a better survival than MA (P = 0.015) with no difference with OA (P = 0.419). In a univariate analysis, EGFR, MMP-13 and E-cadherin expressions didn't show a significant impact on disease-free or overall survival in patients with AWMA.

Conclusion

Based on the clinicopathological and molecular findings in AWMA, OA and MA, AWMA resembles MA more than OA. However, the contrary is true regarding survival, with resemblance to OA more than MA. AWMA remains a vague entity that needs further molecular studies to be grouped with either OA or MA and to validate the significance of the cut-off value of 50% mucinous activity of the tumor, which is also questionable.