Multiplexed DNA Methylation Analysis in Colorectal Cancer Using Liquid Biopsy and Its Diagnostic and Predictive Value

Early diagnosis of colorectal cancer (CRC) is of high importance as prognosis depends on tumour stage at the time of diagnosis. Detection of tumour-specific DNA methylation marks in cfDNA has several advantages over other approaches and has great potential for solving diagnostic needs. We report here the identification of DNA methylation biomarkers for CRC and give insights in our methylation-sensitive restriction enzyme coupled qPCR (MSRE-qPCR) system. Targeted microarrays were used to investigate the DNA methylation status of 360 cancer-associated genes. Validation was done by qPCR-based approaches. A focus was on investigating marker performance in cfDNA from 88 patients (44 CRC, 44 controls). Finally, the workflow was scaled-up to perform 180plex analysis on 110 cfDNA samples, to identify a DNA methylation signature for advanced colonic adenomas (AA). A DNA methylation signature (n = 44) was deduced from microarray experiments and confirmed by quantitative methylation-specific PCR (qMSP) and by MSRE-qPCR, providing for six genes’ single areas under the curve (AUC) values of >0.85 (WT1, PENK, SPARC, GDNF, TMEFF2, DCC). A subset of the signatures can be used for patient stratification and therapy monitoring for progressed CRC with liver metastasis using cfDNA. Furthermore, we identified a 35-plex classifier for the identification of AAs with an AUC of 0.80.

Expression of Osteopontin and Cyclooxygenase-2 in relation to cellular proliferation, in non-tumor colonic mucosa, colonic adenomas and colon adenocarcinoma

Introduction: the participation of Cyclooxygenase-2 (COX-2) and Osteopontin has been postulated in the development of colon cancer, which play an important role in the progression and could be biomarkers for its prognosis, but their role remains controversial. Objective: to determine and to compare the expression of Osteopontin and COX-2 in non-tumor colonic mucosa, colonic adenomas and colon adenocarcinoma, in relation to the cell proliferation index. Methods: the immunohistochemical expression of COX-2, Osteopontin and Ki-67 in formalin fixed paraffin embedded tissue of non-tumor colonic mucosa, colonic adenomas and colon adenocarcinoma were determined and compared. Results: were included 65 cases: 19 of non-tumor colonic mucosa, 13 colonic adenomas and 33 colon adenocarcinomas. There was increased expression of Ki-67 in dysplastic and tumor cells. There was positive expression for COX-2 in adenomas (30.7%) and adenocarcinomas (27.3%), without significant difference between non- tumor colonic mucosa, adenomas and adenocarcinoma (p = 0.888). Osteopontin showed more frequent positivity in adenocarcinomas (72.7%) and adenomas (84.6%) than in non-tumor mucosa (10.5%), (p = <0.0001), without significant differences in its expression between subtypes and grades of adenoma dysplasia, nor between grades of differentiation, extension and proliferation of adenocarcinomas. There was a significant association between Osteopontin expression and the cell proliferation index. No association was observed between the expression of COX-2 and Osteopontin (p = 0.96). Conclusions: Osteopontin overexpression in colon adenocarcinoma and adenomas in comparison with non-tumor colonic mucosa, and its significant relationship with the cell proliferation index, constitutes additional evidence of its possible participation in the colonic carcinogenesis process.

Giant villous adenoma of the sigmoid colon: an unusual cause of homogeneous, segmental bowel wall thickening

Colonic adenomas are commonly encountered lesions that are a precursor of colorectal cancer. Of these, villous adenomas are a rarer, more advanced subtype that are larger in size than tubular adenomas and have a higher risk of malignant transformation. We present a patient with a giant villous adenoma of the sigmoid colon identified on CT as homogeneous segmental bowel wall thickening.

Long Term Outcomes of Colon Polyps with High Grade Dysplasia after Endoscopic Resection

Background The clinical characteristics of patients with high-grade dysplasia (HGD) in colon polyps at baseline colonoscopy in relation to the risk of recurrent colonic adenomas have been unclear. We conducted this hospital- based cohort study recruiting patients who had undergone polypectomy at screening colonoscopy to assess the risk factors of recurrent colonic adenomas. Methods 11,565 subjects had undergone screening colonoscopic examinations between September 1998 and August 2007. The patients who had HGD in colon polyps and had undergone surveillance colonoscopy were eligible. Results A total of 211 patients were recruited. The rates of metachronous adenomas and advanced adenomas at surveillance colonoscopy were 58% and 20%, respectively, during the mean follow-up period of 5.5 ± 1.8 (3–12) years. On univariate logistic regression analysis, the number of adenomas ≥ 3 at baseline colonoscopy was strongly associated with the rates of overall recurrence, multiple recurrence, advanced recurrence, proximal recurrence, and distal adenoma recurrence with odds ratios of 4.32 (2.06–9.04 95%CI), 3.47 (1.67–7.22 95%CI), 2.55 (1.11–5.89 95%CI), 2.46 (1.16–5.22 95%CI), 2.89 (1.44–5.78 95%CI), respectively. On multivariate analysis, male gender [P = 0.010; OR 3.09(1.32–7.25 95% CI)] and number of adenomas ≥ 3 [P = 0.002; OR 3.08(1.52–6.24 95%CI)] at index colonoscopy were significantly associated with recurrent advanced adenomas. Conclusions Recurrence of colonic adenomas at surveillance colonoscopy is common in patients who had undergone polypectomy for colon adenomas with HGD at baseline colonoscopy. The risk of developing future advanced adenomas is associated with the number of colon adenomas and male gender.