Advances in methylation analysis of liquid biopsy in early cancer detection of colorectal and lung cancer.

Methylation patterns in cell-free DNA (cfDNA) have emerged as a promising genomic feature for detecting the presence of cancer and determining its origin. The purpose of this study was to evaluate the diagnostic performance of methylation-sensitive restriction enzyme digestion followed by sequencing (MRE-Seq) using cfDNA, and to investigate the cancer signal origin (CSO) of the cancer using a deep neural network (DNN) analyses for liquid biopsy of colorectal and lung cancer. We developed a selective MRE-Seq method with DNN learning-based prediction model using demethylated-sequence-depth patterns from 63,266 CpG sites using SacII enzyme digestion. A total of 191 patients with stage I-IV cancers (95 lung cancers and 96 colorectal cancers) and 126 noncancer participants were enrolled in this study. Our study showed an area under the receiver operating characteristic curve (AUC) of 0.978 with a sensitivity of 78.1% for colorectal cancer, and an AUC of 0.956 with a sensitivity of 66.3% for lung cancer, both at a specificity of 99.2%. For colorectal cancer, sensitivities for stages I-IV ranged from 76.2 to 83.3% while for lung cancer, sensitivities for stages I-IV ranged from 44.4 to 78.9%, both again at a specificity of 99.2%. The CSO model's true-positive rates were 94.4% and 89.9% for colorectal and lung cancers, respectively. The MRE-Seq was found to be a useful method for detecting global hypomethylation patterns in liquid biopsy samples and accurately diagnosing colorectal and lung cancers, as well as determining CSO of the cancer using DNN analysis.Trial registration: This trial was registered at ClinicalTrials.gov (registration number: NCT04253509) for lung cancer on 5 February 2020, https://clinicaltrials.gov/ct2/show/NCT04253509 . Colorectal cancer samples were retrospectively registered at CRIS (Clinical Research Information Service, registration number: KCT0008037) on 23 December 2022, https://cris.nih.go.kr , https://who.init/ictrp . Healthy control samples were retrospectively registered.

Single center experiences of needle-scopic grasper assisted single incision laparoscopic cholecystectomy for gallbladder benign disease: comparison with conventional 3-port laparoscopic cholecystectomy.

PURPOSE: Single incision laparoscopic cholecystectomy (SILC) has some technical problems. Our group has performed needlescopic grasper assisted SILC (nSILC) to overcome these problems. In this study, we introduce our technique and evaluate the safety and feasibility of this technique compared with the conventional laparoscopic cholecystectomy (CLC). METHODS: The medical records of 485 patients who received nSILC and CLC were reviewed retrospectively. Surgical outcomes including operative time, hospital stay, postoperative pain and perioperative complication were compared between the 2 techniques. RESULTS: Although wound complications were developed more frequently in nSILC group, there was no significant difference between groups in other surgical outcomes. In subgroup analysis, surgical outcomes of nSILC were similar with those of CLC not only in easy group but also in difficult group. CONCLUSION: It seems that nSILC is safe and feasible not only in selected patients but also in difficult cases such as acute cholecystitis.

Innovative technique of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration: A comparative study.

AIM: To investigate the safety and feasibility of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration (nSIL-CBDE) by comparing the surgical outcomes of this technique with those of conventional laparoscopic CBDE (CL-CBDE). METHODS: We retrospectively analyzed the clinical data of patients who underwent CL-CBDE or nSIL-CBDE for the treatment of common bile duct (CBD) stones between January 2000 and December 2014. For performing nSIL-CBDE, a needlescopic grasper was also inserted through a direct puncture below the right subcostal line after introducing a single-port through the umbilicus. The needlescopic grasper helped obtain the critical view of safety by retracting the gallbladder laterally and by preventing crossing or conflict between laparoscopic instruments. The gallbladder was then partially dissected from the liver bed and used for retraction. CBD stones were usually extracted through a longitudinal supraduodenal choledochotomy, mostly using flushing a copious amount of normal saline through a ureteral catheter. Afterward, for the certification of CBD clearance, CBDE was performed mostly using a flexible choledochoscope. The choledochotomy site was primarily closed without using a T-tube, and simultaneous cholecystectomies were performed. RESULTS: During the study period, 40 patients underwent laparoscopic CBDE. Of these patients, 20 underwent CL-CBDE and 20 underwent nSIL-CBDE. The operative time for nSIL-CBDE was significantly longer than that for CL-CBDE (238 ± 76 min vs 192 ± 39 min, P = 0.007). The stone clearance rate was 100% (40/40) in both groups. Postoperatively, the nSIL-CBDE group required less intravenous analgesic (pethidine) (46.5 ± 63.5 mg/kg vs 92.5 ± 120.1 mg/kg, P = 0.010) and had a shorter hospital stay than the CL-CBDE group (3.8 ± 2.0 d vs 5.1 ± 1.7 d, P = 0.010). There was no significant difference in the incidence of postoperative complications between the two groups. CONCLUSION: The results of this study suggest that nSIL-CBDE could be safe and feasible while improving cosmetic outcomes when performed by surgeons trained in conventional laparoscopic techniques.

Safety and feasibility of needlescopic grasper-assisted single-incision laparoscopic cholecystectomy in patients with acute cholecystitis: comparison with three-port laparoscopic cholecystectomy.

INTRODUCTION: Single-incision laparoscopic cholecystectomy (SILC) has been increasing in use steadily, and many researchers have reported the safety and feasibility of SILC. However, most studies were confined to selected patients and excluded patients with acute inflammation. In this study, we evaluated the safety and feasibility of SILC with our technique in patients with acute cholecystitis. PATIENTS AND METHODS: Ninety-six patients with acute cholecystitis undergoing laparoscopic cholecystectomy at Uijeonbu St. Mary's Hospital (Uijeongbu, Korea) between October 2011 and December 2012 were retrospectively reviewed. SILC was performed in 49 patients, and conventional three-port laparoscopic cholecystectomy was performed in 47 patients. Patient demographics and operative outcomes were compared between groups to evaluate the safety and feasibility of SILC using our technique. RESULTS: There were no differences between groups in demographics except for the sex ratio. SILC was more often performed in female patients (69% versus 34%, P=.001). There were no statistically significant differences between groups in terms of operation time, critical view of safety identification time, iatrogenic gallbladder perforation, port-site seroma, and postoperative hospital stay, respectively. One patient in each group required conversion to open cholecystectomy because of massive bleeding. CONCLUSIONS: This study showed that needlescopic grasper-assisted SILC with our technique is acceptable not only in selected patients but also in patients with acute cholecystitis. Lateral and cephalad retraction using a needlescopic grasper and a snake retractor can make SILC safe and easy in acute cholecystitis through better visualization of the triangle of Calot.

Prognostic significance of the lymph node ratio regarding recurrence and survival in rectal cancer patients treated with postoperative chemoradiotherapy.

BACKGROUND/AIMS: TO EVALUATE THE PROGNOSTIC IMPACT OF THE LYMPH NODE RATIO (LNR: the ratio of positive lymph nodes to the total number of lymph nodes examined) on disease recurrence and survival among rectal cancer patients who received curative surgery and postoperative chemoradiotherapy (CRT). METHODS: Between 1995 and 2008, 124 patients with pathologic T3-4 or node-positive rectal cancer underwent curative surgery and postoperative CRT. Postoperative radiotherapy was delivered at a median dose of 50.4 Gy (range, 45 to 59.4 Gy) for 6 weeks. Chemotherapy consisted of a bolus injection of 5-fluorouracil and leucovorin in the first and last week of radiotherapy (91.9%) or daily capecitabine during radiotherapy (8.1%). Further adjuvant chemotherapy was administered after chemoradiation. RESULTS: The median follow-up was 5.1 years. In the multivariate analysis, pathologic N (pN) stage and lymphovascular invasion were significantly associated with disease-free survival and disease-specific survival (p<0.05). However, when the LNR with a cutoff value of 0.2 was included as a covariate in the model, the LNR was highly significant (p<0.001), and the pN stage lost its significance (p>0.05). CONCLUSIONS: The LNR predicts recurrence and survival more accurately than pN stage. The pN stage and the LNR should be considered together when estimating the risk of disease recurrence among rectal cancer patients.

Caveolin-1 mediates Fas-BID signaling in hyperoxia-induced apoptosis.

Fas-mediated apoptosis is a crucial cellular event. Fas, the Fas-associated death domain, and caspase 8 form the death-inducing signaling complex (DISC). Activated caspase 8 mediates the extrinsic pathways and cleaves cytosolic BID. Truncated BID (tBID) translocates to the mitochondria, facilitates the release of cytochrome c, and activates the intrinsic pathways. However, the mechanism causing these DISC components to aggregate and form the complex remains unclear. We found that Cav-1 regulated Fas signaling and mediated the communication between extrinsic and intrinsic pathways. Shortly after hyperoxia (4 h), the colocalization and interaction of Cav-1 and Fas increased, followed by Fas multimer and DISC formation. Deletion of Cav-1 (Cav-1-/-) disrupted DISC formation. Further, Cav-1 interacted with BID. Mutation of Cav-1 Y14 tyrosine to phenylalanine (Y14F) disrupted the hyperoxia-induced interaction between BID and Cav-1 and subsequently yielded a decreased level of tBID and resistance to hyperoxia-induced apoptosis. The reactive oxygen species (ROS) scavenger N-acetylcysteine decreased the Cav-1-Fas interaction. Deletion of glutathione peroxidase-2 using siRNA aggravated the BID-Cav-1 interaction and tBID formation. Taken together, these results indicate that Cav-1 regulates hyperoxia/ROS-induced apoptosis through interactions with Fas and BID, probably via Fas palmitoylation and Cav-1 Y14 phosphorylation, respectively.

Acute appendicitis caused by colonoscopy.

A 48-year-old woman who was without any abnormal past medical history underwent colonoscopy as a screening procedure for colorectal disease. The procedure was uneventful and there was no sign of inflammation around the appendicular orifice or the luminal surface of the cecum. The patient did not complain of pain or significant discomfort throughout the procedure. She then developed pain in the right lower quadrant of the abdomen that evening and this persisted for four days. She visited the outpatient department and underwent abdominal ultrasonography, which showed a swollen appendix with a collection of pericecal fluid. Surgical exploration and appendectomy were performed; the final diagnosis was acute suppurative appendicitis. Colonoscopists should be aware of this rare complication and consider it when making the differential diagnosis of post-colonoscopy abdominal pain.

Prognostic significance of CpG island methylator phenotype and microsatellite instability in gastric carcinoma.

PURPOSE: The influence of molecular characteristics in prognosis of gastric cancer remains unclear. The aim of this study was to evaluate the prognostic value of the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) in gastric cancer. EXPERIMENTAL DESIGN: We studied the methylation profiles of tumor suppressor gene p16, DNA mismatch repair gene hMLH1, and four CpG islands (MINT1, MINT2, MINT25, and MINT31) using bisulfite/methylation-specific PCR, and MSI using five microsatellite markers in 83 resected gastric carcinomas. The CIMP and MSI status were compared with clinicopathologic features and overall survival. RESULTS: Concordant methylation of multiple genes/loci (CIMP-high) was present in 31% of tumors and in 4% of non-neoplastic mucosa, CIMP-low in 55% and 17%, and CIMP-negative in 13% and 79%, respectively (P < 0.001). The prevalence of MSI-high, MSI-low, and MS-stable in tumor was 19%, 17%, and 64%, respectively. MSI status was closely associated with hMLH1 hypermethylation and CIMP status (P = 0.001). In univariate analysis, overall survival was predicted by pathologic stage (P < 0.0001), R0 resection (P = 0.0002), MINT31 methylation (P = 0.04), and CIMP-high status (P = 0.04). MSI status of tumor was not a significant predictor of prognosis. Although CIMP status seemed to be a prognostic predictor of gastric cancer, only pathologic stage remained a significant predictor of prognosis on multivariate analysis (P < 0.001). CONCLUSIONS: Our results indicate that there is an association between CIMP status and MSI status in gastric cancer. Concordant methylation of multiple genes/loci (CIMP-H) is associated with better survival but is not an independent predictor of prognosis in resected gastric cancer.