Significance of Hypermethylation of Tumor-Suppressor Genes PTGER4 and ZNF43 at CpG Sites in the Prognosis of Colorectal Cancer.

The status of DNA methylation in primary tumor tissue and adjacent tumor-free tissue is associated with the occurrence of aggressive colorectal cancer (CRC) and can aid personalized cancer treatments at early stages. Tumor tissue and matched adjacent nontumorous tissue were extracted from 208 patients with CRC, and the correlation between the methylation levels of PTGER4 and ZNF43 at certain CpG loci and the prognostic factors of CRC was determined using the MassARRAY System testing platform. The Wilcoxon signed-rank test, a Chi-square test, and McNemar's test were used for group comparisons, and Kaplan-Meier curves and a log-rank test were used for prediction. The hypermethylation of PTGER4 at the CpG_4, CpG_5, CpG_15, and CpG_17 tumor tissue sites was strongly correlated with shorter recurrence-free survival (RFS), progression-free survival (PFS), and overall survival (OS) [hazard ratio (HR) = 3.26, 95% confidence interval (CI) = 1.38-7.73 for RFS, HR = 2.35 and 95% CI = 1.17-4.71 for PFS, HR = 4.32 and 95% CI = 1.8-10.5 for OS]. By contrast, RFS and PFS were significantly longer in the case of increased methylation of ZNF43 at the CpG_5 site of normal tissue [HR = 2.33, 95% CI = 1.07-5.08 for RFS, HR = 2.42 and 95% CI = 1.19-4.91 for PFS]. Aberrant methylation at specific CpG sites indicates tissue with aggressive behavior. Therefore, the differential methylation of PTGER4 and ZNF43 at specific loci can be employed for the prognosis of patients with CRC.

Differential DNA methylation analysis of SUMF2, ADAMTS5, and PXDN provides novel insights into colorectal cancer prognosis prediction in Taiwan.

BACKGROUND: Patients with colorectal cancer (CRC) undergo surgery, as well as perioperative chemoradiation or adjuvant chemotherapy primarily based on the tumor-node- metastasis (TNM) cancer staging system. However, treatment responses and prognostic outcomes of patients within the same stage vary markedly. The potential use of novel biomarkers can improve prognostication and shared decision making before implementation into certain therapies. AIM: To investigate whether SUMF2, ADAMTS5, and PXDN methylation status could be associated with CRC prognosis. METHODS: We conducted a Taiwanese cohort study involving 208 patients with CRC recruited from Tri-Service General Hospital and applied the candidate gene approach to identify three genes involved in oncogenesis pathways. A methylation-specific polymerase chain reaction (MS-PCR) and EpiTYPER DNA methylation analysis were employed to detect methylation status and to quantify the methylation level of candidate genes in tumor tissue and adjacent normal tissue from participants. We evaluated SUMF2, ADAMTS5, and PXDN methylation as predictors of prognosis, including recurrence-free survival (RFS), progression-free survival (PFS), and overall survival (OS), using a Cox regression model and Kaplan-Meier analysis. RESULTS: We revealed various outcomes related to methylation and prognosis. Significantly shorter PFS and OS were associated with the CpG_3+CpG_7 hypermethylation of SUMF2 from tumor tissue compared with CpG_3+CpG_7 hypomethylation [hazard ratio (HR) = 2.24, 95% confidence interval (CI) = 1.03-4.85 for PFS, HR = 2.56 and 95%CI = 1.08-6.04 for OS]. By contrast, a significantly longer RFS was associated with CpG_2 and CpG_13 hypermethylation of ADAMTS5 from normal tissue compared with CpG_2 and CpG_13 hypomethylation [HR (95%CI) = 0.15 (0.03-0.71) for CpG_2 and 0.20 (0.04-0.97) for CpG_13]. The relationship between the methylation status of PXDN and the prognosis of CRC did not reach statistical significance. CONCLUSION: Our study found that CpG_3+CpG_7 hypermethylation of SUMF2 from tumor tissue was associated with significantly shorter PFS and OS compared with CpG_3+CpG_7 hypomethylation. CpG_2 and CpG_13 hypermethylation of ADAMTS5 from normal tissue was associated with a significantly longer RFS compared with CpG_2 and CpG_13 hypomethylation. These methylation-related biomarkers which have implications for CRC prognosis prediction may aid physicians in clinical decision-making.

Association between gastroesophageal reflux disease and colorectal cancer risk: a population-based cohort study.

PURPOSE: Several studies have investigated the association between gastroesophageal reflux disease (GERD) and colorectal cancer (CRC) risk, but the presented scientific results are highly debatable. This study examined the longitudinal association between GERD and CRC in an Asian population. METHODS: A retrospective cohort study was performed using the National Health Insurance Research Database of Taiwan. The study cohort comprised 45,828 individuals with newly diagnosed GERD (the GERD cohort) and 229,140 age, sex, and date of enrollment-matched patients without GERD (the comparison cohort) from 2000 to 2006. The primary outcome was the incidence of CRC. To estimate the effect of GERD on the risk of CRC, the Cox proportional hazards model was fitted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: There were 785 newly diagnosed CRC patients in the 45,828 patients with GERD. Relatively, there were 2375 incident CRC cases in 229,140 patients without GERD. The incidence rate of CRC for the GERD cohort (17.60 per 10,000 person-years) was significantly higher than the corresponding incidence rate for the comparison cohort (10.22 per 10,000 person-years). After adjustment for confounders, GERD was associated with a significantly increased risk of CRC (adjusted HR,1.76; 95% CI, 1.62-2.90). Of note, a significant association between GERD and CRC risk was evident in both genders. CONCLUSIONS: In conclusion, this nationwide population-based cohort study supports the hypothesis that GERD was associated with a significantly increased risk of CRC. Our findings warrant still further investigation of the underlying mechanisms related to carcinogenic effect of GERD on colorectal carcinoma.