Aneuploidy and elevated CEA indicate an increased risk for metachronous metastasis in colorectal cancer.

PURPOSE: Presently, no markers exist to predict metachronous metastasis at the time a primary colorectal cancer is diagnosed. While aneuploidy indicates poor survival prognosis and elevated carcinoembryonic antigen (CEA) levels the presence of recurrent disease, the predictive value of both markers regarding imminent metachronous metastases is unclear. METHODS: Sixty patients with distant recurrence throughout a 5-year follow-up (TM+) were randomly chosen and 60 patients without metastasis matched to this cohort (TM-). In addition, an enlarged collective (n = 217; n TM+ = 85, n TM- = 132) with median follow-up of 79.2 months was assessed by logistic regression regarding metachronous metastases. Univariate and stepwise regression analyses included clinicopathological characteristics, preoperative CEA levels and aneuploidy assessed by DNA image cytometry. RESULTS: The matched-pair collective showed aneuploidy in 71.1 % (TM-) and 85.0 % (TM+; p = 0.076), and elevated CEA in 24.5 % (TM-) and 52.2 % [TM+; odds ratio (OR), 3.414; p = 0.007]. The enlarged collective presented aneuploidy in 71.2 % (TM-) and 83.5 % (TM+; OR 2.050, p = 0.038), and elevated CEA in 28.6 % (TM-) and 48.9 % (TM+; OR 2.391, p = 0.020). Elevated CEA and aneuploidy did not show any association (p = 0.919). In contrast, logistic regression analyses demonstrated that besides increased T category (OR 1.745, p = 0.019), both elevated CEA level (OR 2.633, p = 0.015) and aneuploidy (OR 1.929, p = 0.058) were independent predictive markers for metachronous metastasis. CONCLUSIONS: Our data show that aneuploidy and elevated CEA levels besides increased T category could serve for individual risk assessment to predict metachronous metastases. The fact that still aneuploidy missed the significance level by a small margin emphasizes the need for larger validation studies.

EB1 protein alteration characterizes sporadic but not ulcerative colitis associated colorectal cancer.

BACKGROUND: While carcinogenesis in Sporadic Colorectal Cancer (SCC) has been thoroughly studied, less is known about Ulcerative Colitis associated Colorectal Cancer (UCC). This study aimed to identify and validate differentially expressed proteins between clinical samples of SCC and UCC to elucidate new insights of UCC/SCC carcinogenesis and progression. RESULTS: Multiplex-fluorescence two-dimensional gel electrophoresis (2-D DIGE) and mass spectrometry identified 67 proteoforms representing 43 distinct proteins. After analysis by Ingenuity Pathway Analysis® (IPA), subsequent Western blot validation proofed the differential expression of Heat shock 27 kDA protein 1 (HSPB1) and Microtubule-associated protein R/EB family, member 1 (EB1) while the latter one showed also expression differences by immunohistochemistry. MATERIALS AND METHODS: Fresh frozen tissue of UCC (n = 10) matched with SCC (n = 10) was investigated. Proteins of cancerous intestinal mucosal cells were obtained by Laser Capture Microdissection (LCM) and compared by 2-D DIGE. Significant spots were identified by mass spectrometry. After IPA, three proteins [EB1, HSPB1, and Annexin 5 (ANXA5)] were chosen for further validation by Western blotting and tissue microarray-based immunohistochemistry. CONCLUSIONS: This study identified significant differences in protein expression of colorectal carcinoma cells from UCC patients compared to patients with SCC. Particularly, EB1 was validated in an independent clinical cohort.

MALDI-imaging reveals thymosin beta-4 as an independent prognostic marker for colorectal cancer.

DNA aneuploidy has been identified as a prognostic factor for epithelial malignancies. Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a powerful tool for direct analysis of multiple proteins in tissue sections while maintaining the cellular and molecular integrity. We compared diploid and aneuploid colon cancer tissues against normal mucosa of the colon by means of IMS. DNA image cytometry determined the ploidy status of tissue samples that were subsequently subjected to MALDI-IMS. After obtaining protein profiles through direct analysis of tissue sections, a discovery and independent validation set were used to predict ploidy status by applying proteomic classification algorithms [Supervised Neural Network (SNN) and Receiver Operating Characteristic (ROC)]. Five peaks (m/z 2,395 and 4,977 for diploid vs. aneuploid comparison as well as m/z 3,376, 6,663, and 8,581 for normal mucosa vs. carcinoma comparison) were significant in both SNN and ROC analysis. Among these, m/z 4,977 was identified as thymosin beta 4 (Tß-4). Tß-4 was subsequently validated in clinical samples using a tissue microarray to predict overall survival in colon cancer patients.