BACKGROUND: Previous studies on synchronous colorectal carcinoma (SCRC) have reported inconsistent results about its clinicopathologic and molecular features and prognostic significance. METHODS: Forty-six patients with multiple advanced tumors (T2 or higher category) who did not receive neoadjuvant chemotherapy and/or radiotherapy and who are not associated with familial adenomatous polyposis were selected and 99 tumors from them were subjected to clinicopathologic and molecular analysis. Ninety-two cases of solitary colorectal carcinoma (CRC) were selected as a control considering the distributions of types of surgeries performed on patients with SCRC and T categories of individual tumors from SCRC. RESULTS: SCRC with multiple advanced tumors was significantly associated with more frequent nodal metastasis (p = .003) and distant metastasis (p = .001) than solitary CRC. KRAS mutation, microsatellite instability, and CpG island methylator phenotype statuses were not different between SCRC and solitary CRC groups. In univariate survival analysis, overall and recurrence-free survival were significantly lower in patients with SCRC than in patients with solitary CRC, even after adjusting for the extensiveness of surgical procedure, adjuvant chemotherapy, or staging. Multivariate Cox regression analysis revealed that tumor multiplicity was an independent prognostic factor for overall survival (hazard ratio, 4.618; 95% confidence interval, 2.126 to 10.030; p < .001), but not for recurrence-free survival (p = .151). CONCLUSIONS: Findings suggested that multiplicity of advanced T category–tumors might be associated with an increased risk of nodal metastasis and a risk factor for poor survival, which raises a concern about the guideline of American Joint Committee on Cancer's tumor-node-metastasis staging that T staging of an index tumor determines T staging of SCRC.
Adenomatous Polyposis Coli ; Chemotherapy, Adjuvant ; Colorectal Neoplasms ; CpG Islands ; Drug Therapy ; Humans ; Joints ; Microsatellite Instability ; Neoplasm Metastasis ; Phenotype ; Radiotherapy ; Risk Factors

BACKGROUND: Although colorectal sessile serrated adenomas/polyps (SSA/Ps) with morphologic dysplasia are regarded as definite high-risk premalignant lesions, no reliable grading or risk-stratifying system exists for non-dysplastic SSA/Ps. The accumulation of CpG island methylation is a molecular hallmark of progression of SSA/Ps. Thus, we decided to classify non-dysplastic SSA/Ps into risk subgroups based on the extent of CpG island methylation. METHODS: The CpG island methylator phenotype (CIMP) status of 132 non-dysplastic SSA/Ps was determined using eight CIMP-specific promoter markers. SSA/Ps with CIMP-high and/or MLH1 promoter methylation were regarded as a high-risk subgroup. RESULTS: Based on the CIMP analysis results, methylation frequency of each CIMP marker suggested a sequential pattern of CpG island methylation during progression of SSA/P, indicating MLH1 as a late-methylated marker. Among the 132 non-dysplastic SSA/Ps, 34 (26%) were determined to be high-risk lesions (33 CIMP-high and 8 MLH1-methylated cases; seven cases overlapped). All 34 high-risk SSA/Ps were located exclusively in the proximal colon (100%, p = .001) and were significantly associated with older age (≥ 50 years, 100%; p = .003) and a larger histologically measured lesion size (> 5 mm, 100%; p = .004). In addition, the high-risk SSA/Ps were characterized by a relatively higher number of typical base-dilated serrated crypts. CONCLUSIONS: Both CIMP-high and MLH1 methylation are late-step molecular events during progression of SSA/Ps and rarely occur in SSA/Ps of young patients. Comprehensive consideration of age (≥ 50), location (proximal colon), and histologic size (> 5 mm) may be important for the prediction of high-risk lesions among non-dysplastic SSA/Ps.
Colon ; Colorectal Neoplasms ; CpG Islands ; Diagnosis, Differential ; DNA Methylation ; Humans ; Methylation ; Phenotype

Background: Urgent-start peritoneal dialysis (PD) is applied to patients who need PD within two weeks but are able to wait for more than 48 hours before starting PD. To evaluate the usefulness of percutaneous PD catheter insertion in urgent-start PD, we reviewed the clinical outcomes of percutaneous catheter insertion with immediate start PD and surgical insertion with longer break-in time in Pusan National University Hospital. Methods: This study included 177 patients who underwent urgent-start PD. Based on the PD catheter insertion techniques, the patients with urgent-start PD were divided into percutaneous (n = 103) and surgical (n = 74) groups. For the percutaneous group, a modified Seldinger percutaneous catheter insertion with immediate initiation of continuous ambulatory PD was performed by nephrologists. Results: The percutaneous group showed higher serum urea nitrogen, creatinine, and lower serum albumin compared with the surgical group (P < 0.05). Ninety-day infectious and mechanical complications showed no significant differences between the two groups. Ninety-day peritonitis in the percutaneous group was 9.7% compared to 5.4% in the surgical group (P = not significant [NS]). Major leakage was 3.9% in the percutaneous group compared to 1.4% in the surgical group (P = NS). Overall infectious and mechanical complication-free survival was not significantly different between the two groups. The percutaneous group and surgical group showed no statistical difference with respect to catheter survival over the entire observation period (P = NS). Conclusion This study suggests that urgent-start PD can be applied safely with percutaneous catheter insertion by nephrologists with no break-in period.