Abstract 3871: Expression of MACC1, a metastasis-related protein, associated with the progression of colorectal cancer

Abstract

Background: Colorectal cancer (CRC) as the second most common cancer in western world has different prognostic basis in contrast to other cancers. Its pathologic staging is the main prognostic factor. Recently, MACC1 has been proposed as an effective marker for identifying patients at high risk for the development of distant metastases when MACC1 is highly expressed in the not (yet) metastasized primary tumor. Aims and Methods: We aimed to assess the cellular and sub-cellular expression of MACC1 in age matched normal, adenomatous and cancerous colonic tissue samples. Samples were recruited from pathology department of Howard University Hospital. The Tissue Micro Array (TMA) sections were made from all duplicated samples and put in three different TMA slides as normal matched (n=44), adenomatous (n=60) and adenocarcinoma (n=36). Total of 140 samples were stained for MACC1 by Immuno-Histo-Chemistry method. Then, all three TMA were read by two pathologists including one GI pathologist. The expression were reported as staining 0, 1, 2, 3, 4 which refer to none, less than 10%, 10-25%, 25-50%, 50-75%, >75%, respectively. Sub-cellular staining was reported as nuclear, cytoplasmic, or both. Results: Of 140 samples, 36 were adenocarcinomas (mean age: 64.3; M/F: 16/20); 60 adenomatous (mean age: 64.8; M/F: 31/29); 44 normal controls (mean age 65.8; M/F: 22/22). Adenocarcinomas received score 4 in 86.1% of cases which was significantly higher (p<0.05) than normal (15.9%) and adenomatous (28.3%) cases. MACC1 stained more in cytoplasm (88.6%) in contrast to normal (44.7%) and adenomatous cases (32.1%) with P < 0.05. Observationally, high grade adenomas had higher scores (3 or 4) than low grade ones (P=0.1). Of total 18 patients with stage 3 and/or 4, 14 scored 4 and had cytoplasmic stainning. Conclusions: Our data showed that MACC1 not only can be a prognostic and pathological marker to differentiate high grade from low grade adenoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3871. doi:10.1158/1538-7445.AM2011-3871