Limited wedge resection for T1 colon cancer (LIMERIC-II trial) - rationale and study protocol of a prospective multicenter clinical trial.

Background: The sole presence of deep submucosal invasion is shown to be associated with a limited risk of lymph node metastasis. This justifies a local excision of suspected deep submucosal invasive colon carcinomas (T1 CCs) as a first step treatment strategy. Recently Colonoscopy-Assisted Laparoscopic Wedge Resection (CAL-WR) has been shown to be able to resect pT1 CRCs with a high R0 resection rate, but the long term outcomes are lacking.

Diagnostic value of radiological staging and surveillance for T1 colorectal carcinomas: A multicenter cohort study.

Background: The role of radiological staging and surveillance imaging is under debate for T1 colorectal cancer (CRC) as the risk of distant metastases is low and imaging may lead to the detection of incidental findings.

Objective: The aim of this study was to evaluate the yield of radiological staging and surveillance imaging for T1 CRC.

Methods: In this retrospective multicenter cohort study, all patients of 10 Dutch hospitals with histologically proven T1 CRC who underwent radiological staging in the period 2000-2014 were included.

Consensus molecular subtype 4 (CMS4)-targeted therapy in primary colon cancer: A proof-of-concept study.

Background: Mesenchymal Consensus Molecular Subtype 4 (CMS4) colon cancer is associated with poor prognosis and therapy resistance. In this proof-of-concept study, we assessed whether a rationally chosen drug could mitigate the distinguishing molecular features of primary CMS4 colon cancer.

Methods: In the ImPACCT trial, informed consent was obtained for molecular subtyping at initial diagnosis of colon cancer using a validated RT-qPCR CMS4-test on three biopsies per tumor (Phase-1, n=69 patients), and for neoadjuvant CMS4-targeting therapy with imatinib (Phase-2, n=5).

[Supportive treatment and decision-making in a patient with severe anaemia when blood transfusion is not an option].

In severely anaemic patients, blood transfusions remain the standard of care when haemoglobin levels become dangerously low. However, in some situations blood transfusion is not an option. In this clinical lesson, we present a case of a young Jehovah's Witness who developed a life-threatening anaemia due to a gastro-intestinal bleeding.

Colonoscopic-Assisted Laparoscopic Wedge Resection for Colonic Lesions: A Prospective Multicenter Cohort Study (LIMERIC-Study).

Objective: The aim of this study was to evaluate the safety and efficacy of a modified CAL-WR.

Summary Background Data: The use of segmental colectomy in patients with endoscopically unresectable colonic lesions results in significant morbidity and mortality. CAL-WR is an alternative procedure that may reduce morbidity.

Full-Thickness Scar Resection After R1/Rx Excised T1 Colorectal Cancers as an Alternative to Completion Surgery.

Introduction: Local full-thickness resections of the scar (FTRS) after local excision of a T1 colorectal cancer (CRC) with uncertain resection margins is proposed as an alternative strategy to completion surgery (CS), provided that no local intramural residual cancer (LIRC) is found. However, a comparison on long-term oncological outcome between both strategies is missing.

Methods: A large cohort of patients with consecutive T1 CRC between 2000 and 2017 was used.

Tumour-stroma ratio has poor prognostic value in nonpedunculated T1 colorectal cancer: A multicentre case-cohort study.

Background: Current risk stratification models for early invasive (T1) colorectal cancer are not able to discriminate accurately between prognostic favourable and unfavourable tumours, resulting in over-treatment of a large (>80%) proportion of T1 colorectal cancer patients. The tumour-stroma ratio (TSR), which is a measure for the relative amount of desmoplastic tumour stroma, is reported to be a strong independent prognostic factor in advanced-stage colorectal cancer, with a high stromal content being associated with worse prognosis and survival. We aimed to investigate whether the TSR predicts clinical outcome in patients with non-pedunculated T1 colorectal cancer.

Tumour-stroma ratio has poor prognostic value in non-pedunculated T1 colorectal cancer: A multi-centre case-cohort study.

Background: Current risk stratification models for early invasive (T1) colorectal cancer are not able to discriminate accurately between prognostic favourable and unfavourable tumours, resulting in over-treatment of a large (>80%) proportion of T1 colorectal cancer patients. The tumour-stroma ratio (TSR), which is a measure for the relative amount of desmoplastic tumour stroma, is reported to be a strong independent prognostic factor in advanced-stage colorectal cancer, with a high stromal content being associated with worse prognosis and survival. We aimed to investigate whether the TSR predicts clinical outcome in patients with non-pedunculated T1 colorectal cancer.

Management of delayed bleeding after endoscopic mucosal resection of large colorectal polyps: a retrospective multi-center cohort study.

 Delayed bleeding (DB) is the most frequent major adverse event after endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs). Evidence-based guidelines for management of DB are lacking. We aimed to evaluate the clinical presentation, treatment and outcome of patients with DB and to determine factors associated with hemostatic therapy.

Associations of non-pedunculated T1 colorectal adenocarcinoma outcome with consensus molecular subtypes, immunoscore, and microsatellite status: a multicenter case-cohort study.

Advanced colorectal cancer (CRC) consensus molecular subtype 4 (CMS4) or CRC with a low immunoscore is associated with shorter survival times. Non-metastatic CRC with microsatellite instability (MSI) is associated with a lower risk of recurrence. We evaluated outcome (lymph node metastases [LNM] or cancer recurrence) in these tumor subtypes in patients with surgically-removed non-pedunculated T1 CRC by performing a multicenter case-cohort study.

Periprocedural adverse events after endoscopic resection of T1 colorectal carcinomas.

Background And Aims: In contrast to the adverse event (AE) risk of endoscopic resection (ER) of adenomas, the intra- and postprocedural AE risks of ER of T1 colorectal cancer (CRC) are scarcely reported in the literature. It is unclear whether ER of early CRCs, which grow into the submucosal layer and sometimes show incomplete lifting, is associated with an increased AE risk. We aimed to identify the AE rate after ER of T1 CRCs and to identify the risk factors associated with these AEs.

Tumor Seeding During Colonoscopy as a Possible Cause for Metachronous Colorectal Cancer.

Background And Aims: In patients who have undergone surgery for colorectal cancer (CRC), 3% have recurrence of (metachronous) CRC. We investigated whether tumor seeding during colonoscopy (iatrogenic implantation of tumor cells in damaged mucosa) increases risk for metachronous CRC.

Methods: In a proof of principle study, we collected data from the Dutch National Pathology Registry for patients with a diagnosis of CRC from 2013 through 2015, with a second diagnosis of CRC within 6 months to 3.

Pedunculated Morphology of T1 Colorectal Tumors Associates With Reduced Risk of Adverse Outcome.

Background & Aims: Risk stratification for adverse events, such as metastasis to lymph nodes, is based only on histologic features of tumors. We aimed to compare adverse outcomes of pedunculated vs nonpedunculated T1 colorectal cancers (CRC).

Methods: We performed a retrospective study of 1656 patients diagnosed with T1CRC from 2000 through 2014 at 14 hospitals in The Netherlands.

Histologic Factors Associated With Need for Surgery in Patients With Pedunculated T1 Colorectal Carcinomas.

Background & Aims: Most patients with pedunculated T1 colorectal tumors referred for surgery are not found to have lymph node metastases, and were therefore unnecessarily placed at risk for surgery-associated complications. We aimed to identify histologic factors associated with need for surgery in patients with pedunculated T1 colorectal tumors.

Methods: We performed a cohort-nested matched case-control study of 708 patients diagnosed with pedunculated T1 colorectal tumors at 13 hospitals in The Netherlands, from January 1, 2000 through December 31, 2014, followed for a median of 44 months (interquartile range, 20-80 months).

Multicentre prospective evaluation of real-time optical diagnosis of T1 colorectal cancer in large non-pedunculated colorectal polyps using narrow band imaging (the OPTICAL study).

Objective: This study evaluated the preresection accuracy of optical diagnosis of T1 colorectal cancer (CRC) in large non-pedunculated colorectal polyps (LNPCPs).

Design: In this multicentre prospective study, endoscopists predicted the histology during colonoscopy in consecutive patients with LNPCPs using a standardised procedure for optical assessment. The presence of morphological features assessed with white light, and vascular and surface pattern with narrow-band imaging (NBI) were recorded, together with the optical diagnosis, the confidence level of prediction and the recommended treatment.

Extent of unnecessary surgery for benign rectal polyps in the Netherlands.

Background And Aims: Minimally invasive techniques are available to safely and efficaciously remove even the largest rectal polyps. This study aimed to investigate the magnitude of cases still referred for radical rectal surgery and the reasons for these referrals and to perform a re-evaluation of cases potentially suitable for endoscopic therapy.

Methods: A retrospective analysis of data from the Dutch Pathology Registry (Pathologic Anatomic Nationwide Automated Archive) was performed using the records of patients who underwent major surgical treatment for a histologically proven benign rectal polyp between 2005 and 2014 in the Netherlands.

The prognostic value of lymph node yield in the earliest stage of colorectal cancer: a multicenter cohort study.

Background: In patients with stage II colorectal cancer (CRC) the number of surgically retrieved lymph nodes (LNs) is associated with prognosis, resulting in a minimum of 10-12 retrieved LNs being recommended for this stage. Current guidelines do not provide a recommendation regarding LN yield in T1 CRC. Studies evaluating LN yield in T1 CRC suggest that such high LN yields are not feasible in this early stage, and a lower LN yield might be appropriate.

Diagnosis of T1 colorectal cancer in pedunculated polyps in daily clinical practice: a multicenter study.

T1 colorectal cancer can be mimicked by pseudo-invasion in pedunculated polyps. British guidelines are currently one of the few which recommend diagnostic confirmation of T1 colorectal cancer by a second pathologist. The aim of this study was to provide insights into the accuracy of histological diagnosis of pedunculated T1 colorectal cancer in daily clinical practice.