The consensus molecular subtype (CMS) classification of colorectal cancer is based on bulk transcriptomics. The underlying epithelial cell diversity remains unclear. We analyzed 373,058 single-cell transcriptomes from 63 patients, focusing on 49,155 epithelial cells. We identified a pervasive genetic and transcriptomic dichotomy of malignant cells, based on distinct gene expression, DNA copy number and gene regulatory network. We recapitulated these subtypes in bulk transcriptomes from 3,614 patients. The two intrinsic subtypes, iCMS2 and iCMS3, refine CMS. iCMS3 comprises microsatellite unstable (MSI-H) cancers and one-third of microsatellite-stable (MSS) tumors. iCMS3 MSS cancers are transcriptomically more similar to MSI-H cancers than to other MSS cancers. CMS4 cancers had either iCMS2 or iCMS3 epithelium; the latter had the worst prognosis. We defined the intrinsic epithelial axis of colorectal cancer and propose a refined ‘IMF’ classification with five subtypes, combining intrinsic epithelial subtype (I), microsatellite instability status (M) and fibrosis (F).

Routine swab cultures are unnecessary and do not affect management and outcome. The use of post-operative antibiotics may reduce the rates of recurrence, but this benefit was not found to be statistically significant.

VAAFT is useful in the identification of fistula tracts and enables closure of the internal opening. Adequate closure is essential with the method used to close large or fibrotic internal openings being the determining factor for success or failure. The OTSC system delivered the most consistent result without leaving a substantial perianal wound. Ensuring thorough curettage and drainage of the tract during VAAFT is also important to facilitate healing. We believe that this understanding will bring about a decrease in the high recurrence rates currently seen in many series of anal fistulae.

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AIMTo determine the clinical characteristics of patients undergoing palliative surgery for Krukenberg tumors, including disease presentation, outcomes, and prognostic factors.METHODSThis was a retrospective clinical study of all patients who underwent palliative surgery for Krukenberg tumors between January 2004 and December 2015. Patient information was obtained from inpatient and outpatient case notes as well as the hospital electronic records. Patients who underwent potentially curative resection, and patients with Krukenberg tumors who did not undergo surgery were also excluded from the study. Palliative surgery was defined as those performed for either alleviation of symptoms or for asymptomatic patients for whom surgical removal of the tumors were deemed necessary following a multidisciplinary consensus. Tumors were diagnosed pre-operatively by computed tomography scans and all had histologic confirmation of the surgical specimens.RESULTSOver the study duration, 38 female patients underwent palliative surgery for Krukenberg tumors at our institution. Mean age was 54.2 ± 11.7 years. The colon was the most frequent primary source of metastases (n = 21) followed by the stomach (n = 4). Prophylactic palliative surgery was performed for eight (21.1%) asymptomatic patients. Median post-operative length of stay was 8 d (IQR 6-12 d). Five patients (13.2%) experienced post-operative complications, although high grade morbidity was only seen in one patient (2.6%). Median overall survival from surgery was 17 mo (95%CI: 12.1-21.9) at a median follow-up duration of 12 mo (IQR 8-17 mo). The median survival was shorter for patients who underwent emergency surgery, younger patients, those with a colorectal primary, larger tumors, or synchronous peritoneal or hepatic metastases.CONCLUSIONPalliative surgery for Krukenberg tumors can be performed safely with acceptable complication rates. Bilateral oophorectomy should be performed to prevent the risk of symptomatic contralateral tumors.

Coke Zero is a useful alternative solvent for PEG. It is well tolerated, more palatable, leads to quicker consumption of the bowel preparation and results in better quality cleansing.

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INTRODUCTION: Natural orifice specimen extraction is the next step in minimally invasive colorectal surgery but can be technically challenging, with additional risks, especially for oncologic surgery. For several key reasons, sigmoid volvulus is well suited for natural orifice specimen extraction surgery. We describe our method and experience with double-stapled anastomosis transrectal natural orifice specimen extraction for sigmoid volvulus. TECHNIQUE: Using 3- or 4-port laparoscopy, the mesentery is separated from the long sigmoid loop. After the distal bowel is tied off and washed out, the rectum is completely transected and the proximal bowel delivered transrectally through a wound protector. Proximal transection is performed externally, and the circular stapler anvil is set before the bowel is returned into the abdominal cavity. The rectum stump is closed with an endoscopic linear stapler, and a circular-stapled anastomosis is performed. RESULTS: After successful endoscopic decompression, 6 patients underwent elective laparoscopic sigmoidectomy with natural orifice specimen extraction for volvulus at China Medical University Hospital from 2015 to 2020. The median operative time was 179 minutes (range, 151–236 min). No intraoperative complications were encountered. The median postoperative length of stay was 4 days (range, 2–9 d). One patient experienced postoperative small-bowel ileus resulting in readmission. The median follow-up duration was 12 months (range, 2–49 mo). One recurrence of volvulus was recorded 27 months postsurgery. CONCLUSION: Uncomplicated sigmoid volvulus can be treated effectively with sigmoidectomy and natural orifice specimen extraction. Surgeons who attempt this procedure should be well versed with conventional laparoscopy but do not necessarily need to be experienced with natural orifice specimen extraction for successful surgery.