Herbert Andres

Identification of Nicotinamide N-Methyltransferase as a Novel Serum Tumor Marker for Colorectal Cancer

Purpose: The goal of this study was to identify and validate novel serum markers of human colorectal cancer as potential candidates for noninvasive detection of early colorectal neoplasm. Experimental Design: Employing two-dimensional gel electrophoresis and mass spectrometry, we analyzed 16 matched colorectal cancer and adjacent normal tissue samples. Proteins found to be elevated in cancer tissue were further validated by generating antibodies which were used for immunoblotting of tissue samples and for the development of highly sensitive immunoassays for assessment of serum samples. Results: In total, 735 different proteins were identified in colon tissue. Strong elevation in colorectal cancer for five proteins was confirmed by immunoblot analysis: transforming growth factor-β induced protein ig-h3 (βIG-H3), nicotinamide N-methyltransferase (NNMT), nucleoside diphosphate kinase A (nm23-H1), purine nucleoside phosphorylase (PNPH), and mannose-6-phosphate receptor binding protein 1 (M6P1). Elevated levels of NNMT, which is not predicted to be secreted but is known as a cytoplasmic protein, were found in serum from patients with colorectal cancer. Employing a receiver-operating characteristic curve based on the measurement of 109 patients with colorectal cancer and 317 healthy controls, we obtained an area under the curve of 0.84 for NNMT, which was superior to the established tumor marker carcinoembryogenic antigen with an area under the curve of 0.78. Conclusions: It is proposed that NNMT serum levels may have significance in the early detection and in the management of patients with colorectal cancer.

A Combination of Serum Markers for the Early Detection of Colorectal Cancer

Purpose: Fecal occult blood testing is recommended as first-line screening to detect colorectal cancer (CRC). We evaluated markers and marker combinations in serum as an alternative to improve the detection of CRC. Experimental Design: Using penalized logistic regression, 6 markers were selected for evaluation in 1,027 samples (301 CRC patients, 143 patients with adenoma, 266 controls, 141 disease controls, and 176 patients with other cancer). The diagnostic performance of each marker and of marker combinations was assessed. Results: To detect CRC from serum samples, we tested 22 biomarkers. Six markers were selected for a marker combination, including the known tumor markers CEA (carcinoembryonic antigen) and CYFRA 21-1 as well as novel markers or markers that are less routinely used for the detection of CRC: ferritin, osteopontin (OPN), anti-p53, and seprase. CEA showed the best sensitivity at 95% specificity with 43.9%, followed by seprase (42.4%), CYFRA 21-1 (35.5%), OPN (30.2%), ferritin (23.9%), and anti-p53 (20.0%). A combination of these markers gave 69.6% sensitivity at 95% specificity and 58.7% at 98% specificity. Focusing on International Union against Cancer (UICC) stages 0–III reduced the sensitivity slightly to 68.0% and 53.3%, respectively. In a subcollective, with matched stool samples (75 CRC cases and 234 controls), the sensitivity of the marker combination was comparable with fecal immunochemical testing (FIT) with 82.4% and 68.9% versus 81.8% and 72.7% at 95% and 98% specificity, respectively. Conclusions: The performance of the serum marker combination is comparable with FIT. This provides a novel tool for CRC screening to trigger a follow-up colonoscopy for a final diagnosis. Clin Cancer Res; 16(24); 6111–21. ©2010 AACR.

Improved Diagnosis of Colorectal Cancer Using a Combination of Fecal Occult Blood and Novel Fecal Protein Markers

BACKGROUND & AIMS Annual testing for fecal occult blood is recommended as first-line screening for the detection of colorectal cancer (CRC), but is affected by limited sensitivity. We initiated a proteomics-based search for novel biomarkers to improve the sensitivity of detection of CRC in stool samples. METHODS Six markers, including immunologic fecal occult blood test (iFOBT), were evaluated in a collective of 551 samples (186 CRC, 113 advanced adenoma, and 252 control patients) to establish the diagnostic performance of each marker and marker combinations. RESULTS We tested the known stool markers hemoglobin (iFOBT), hemoglobin-haptoglobin, calprotectin, carcinoembryogenic antigen, and the novel fecal markers tissue inhibitor of metalloproteinase-1 (TIMP-1) and S100A12. The best diagnostic performance was found for S100A12 with an area under the curve of 0.95, followed by TIMP-1 (0.92), hemoglobin-haptoglobin (0.92), hemoglobin (0.91), calprotectin (0.90), and carcinoembryogenic antigen (0.66). By using Bayes logistic regression as a mathematic model, the highest sensitivity (88%) for the detection of CRC at 95% specificity was obtained with the marker pair S100A12 and hemoglobin-haptoglobin. Increasing the specificity to 98%, the combination of S100A12, hemoglobin-haptoglobin, and TIMP-1 resulted in a sensitivity of 82%, with the highest increase of sensitivity found in early tumor stages (international union against cancer stage I: 74% sensitivity vs 57% of the best single marker). CONCLUSIONS Depending on the specificity selected, a marker pair, S100A12 and hemoglobin-haptoglobin, or a triple combination including TIMP-1, allowed the detection of CRC at significantly higher rates than can be obtained with iFOBT alone.

Abstract 2738: Early detection of colorectal cancer applying a combination of serum markers

Background: Fecal occult blood testing (FOBT) is the recommended first line screening for the detection of colorectal cancer (CRC). To improve the detection of CRC we evaluated serum markers and combinations of serum markers as an alternative approach. Methods: Applying Lasso Regression, a specialized form of penalized logistic regression, we selected six markers for an evaluation in a collective of 857 patients including 301 CRC patients, 143 patients with adenoma, 266 healthy controls and 147 disease controls. For each marker and marker combination the performance was assessed. Results: We tested a total of 22 biomarkers for the detection of CRC from serum. Of these six markers were selected for a marker combination by Lasso Regression. Included were the well-known tumor markers CEA and CYFRA21-1 as well as novel markers or markers that are less routinely used for the detection of CRC: ferritin, osteopontin, anti-p53 and seprase. CEA showed the best sensitivity of all markers with 43.9 % at 95% specificity, followed by seprase (42.4%), CYFRA21-1 (35.5%), osteopontin (30.2%), ferritin (23.9%) and anti-p53 (20.0%). When these markers were combined a sensitivity of 72.3% was reached at a corresponding specificity of 95% and of 62.1% at 98% specificity. Focusing on more screening relevant stages, UICC stages 0-III, reduced the sensitivity slightly to 68.0% and 53.3%, respectively. In a sub-collective where matched stool samples were available (75 CRC cases and 234 controls) the sensitivity of the marker combination was comparable to fecal immunochemical testing (FIT) with 82.4% and 68.9% vs. 81.8% and 72.7% at 95% and 98% specificity, respectively. Conclusion: When six markers were combined to detect CRC from serum, the combination reached a performance that was comparable to FIT. This provides a novel tool for CRC screening to trigger a follow-up colonoscopy for a final diagnosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2738.