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. A sample of 128 cases diagnosed as pedunculated T1 colorectal cancer between 2000 and 2014 from 10 Dutch hospitals was selected for histological review. Firstly, two Dutch expert gastrointestinal pathologists reviewed all hematoxylin-eosin stained slides. In 20 cases the diagnosis T1 colorectal cancer was not confirmed (20/128; 16%). The discordant cases were subsequently discussed with a third Dutch gastrointestinal pathologist and a consensus diagnosis was agreed. The revised diagnoses were pseudo-invasion in 10 cases (10/128; 8%), high-grade dysplasia in 4 cases (4/128; 3%), and equivocal in 6 cases (6/128; 5%). To further validate the consensus diagnosis, the discordant cases were reviewed by an independent expert pathologist from the United Kingdom. A total of 39 cases were reviewed blindly including the 20 cases with a revised diagnosis and 19 control cases where the Dutch expert panel agreed with the original reporting pathologists diagnosis. In 19 of the 20 cases with a revised diagnosis the British pathologist agreed that T1 colorectal cancer could not be confirmed. Additionally, amongst the 19 control cases the British pathologist was unable to confirm T1 colorectal cancer in a further 4 cases and was equivocal in 3 cases. In conclusion, both generalist and expert pathologists experience diagnostic difficulty distinguishing pseudo-invasion and high-grade dysplasia from T1 colorectal cancer. In order to prevent overtreatment, review of the histology of pedunculated T1 colorectal cancers by a second pathologist should be considered with discussion of these cases at a multidisciplinary meeting.

Clinical outcomes of biliary drainage of malignant biliary obstruction due to colorectal cancer metastases: A systematic review.

BACKGROUND AND AIMS: Malignant biliary obstruction is an ominous complication of metastatic colorectal cancer (mCRC). Biliary drainage is frequently performed to relieve symptoms of jaundice or enable palliative systemic therapy, but effective drainage can be difficult to accomplish. The aim of this study is to summarize literature on clinical outcomes of biliary drainage in mCRC patients with malignant biliary obstruction. METHODS: We searched Medline and EMBASE for studies that included patients with malignant biliary obstruction secondary to mCRC, treated with endoscopic and/or percutaneous biliary drainage. We summarized available data on technical success, clinical success, adverse events, systemic therapy administration and survival after biliary drainage. RESULTS: After screening 3584 references and assessing 509 full-text articles, seven cohort studies were included. In these studies, rates of technical success, clinical success and adverse events varied between 63%-94%, 42%-81%, and 19%-39%, respectively. Subsequent chemotherapy was administered in 17%-56% of patients. Overall survival varied between 40 and 122 days across studies (278-365 days in patients who received subsequent chemotherapy, 42-61 days in patients who did not). CONCLUSIONS: Successful biliary drainage in mCRC patients can be challenging to achieve and is frequently associated with adverse events. Overall survival after biliary drainage is limited, but is significantly longer in patients treated with subsequent systemic therapy. Expected benefits of biliary drainage should be carefully weighed against its risks.

Histological changes in patients with chronic upper gastrointestinal ischaemia.

AIMS: Diagnosing chronic upper gastrointestinal ischaemia (CUGI) remains a challenge in clinical practice. Histological examination of biopsy material currently plays no role in the diagnosis of transient CUGI, as little is known about gastrointestinal histology in these patients. The aim of this study was to investigate upper gastrointestinal histology in patients with well-defined CUGI. METHODS AND RESULTS: Consecutive patients suspected of CUGI were included prospectively and underwent a diagnostic work-up existing of upper endoscopy, gastrointestinal tonometry and computed tomography (CT) or magnetic resonance (MR) angiography. Results were discussed in a multidisciplinary team and a consensus diagnosis was made. Endoscopic biopsy samples were taken from the descending duodenum, gastric antrum and corpus, and scored using the Sydney, Vienna, Chiu, Marsh and Operative Link for Gastritis Assessment (OLGA) classifications. Gastropathy was scored present or absent. Seventy-nine patients were analysed in 8months. CUGI was diagnosed in 41 patients (52%): 36 males, mean age 60 (17-86) years. Prevalence of gastropathy was significantly higher in patients with ischaemia (P=0.025). No other differences were found between patients with and without ischaemia. CONCLUSIONS: Histological examination of biopsy samples plays no definitive role in diagnosing CUGI, but the presence of histological signs of reactive gastropathy can be used to support the clinical diagnosis of ischaemia.

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. METHODS: Hematoxylin and eosin (H&E)-stained tumour tissue slides from a retrospective multi-centre case cohort of patients with non-pedunculated surgically treated T1 colorectal cancer were assessed for TSR by two independent observers who were blinded for clinical outcomes. The primary end point was adverse outcome, which was defined as the presence of lymph node metastasis in the resection specimen or colorectal cancer recurrence during follow-up. RESULTS: All 261 patients in the case cohort had H&E slides available for TSR scoring. Of these, 183 were scored as stroma-low, and 78 were scored as stroma-high. There was moderate inter-observer agreement (κ = 0.42). In total, 41 patients had lymph node metastasis, 17 patients had recurrent cancer and five had both. Stroma-high tumours were not associated with an increased risk for an adverse outcome (adjusted hazard ratio = 0.66, 95% confidence interval 0.37-1.18; p = 0.163). CONCLUSIONS: Our study emphasises that existing prognosticators may not be simply extrapolated to T1 colorectal cancers, even though their prognostic value has been widely validated in more advanced-stage tumours.

Endoscopic innovations to increase the adenoma detection rate during colonoscopy.

Up to a quarter of polyps and adenomas are missed during colonoscopy due to poor visualization behind folds and the inner curves of flexures, and the presence of flat lesions that are difficult to detect. These numbers may however be conservative because they mainly come from back-to-back studies performed with standard colonoscopes, which are unable to visualize the entire mucosal surface. In the past several years, new endoscopic techniques have been introduced to improve the detection of polyps and adenomas. The introduction of high definition colonoscopes and visual image enhancement technologies have been suggested to lead to better recognition of flat and small lesions, but the absolute increase in diagnostic yield seems limited. Cap assisted colonoscopy and water-exchange colonoscopy are methods to facilitate cecal intubation and increase patients comfort, but show only a marginal or no benefit on polyp and adenoma detection. Retroflexion is routinely used in the rectum for the inspection of the dentate line, but withdrawal in retroflexion in the colon is in general not recommended due to the risk of perforation. In contrast, colonoscopy with the Third-Eye Retroscope® may result in considerable lower miss rates compared to standard colonoscopy, but this technique is not practical in case of polypectomy and is more time consuming. The recently introduced Full Spectrum Endoscopy™ colonoscopes maintains the technical capabilities of standard colonoscopes and provides a much wider view of 330 degrees compared to the 170 degrees with standard colonoscopes. Remarkable lower adenoma miss rates with this new technique were recently demonstrated in the first randomized study. Nonetheless, more studies are required to determine the exact additional diagnostic yield in clinical practice. Optimizing the efficacy of colorectal cancer screening and surveillance requires high definition colonoscopes with improved virtual chromoendoscopy technology that visualize the whole colon mucosa while maintaining optimal washing, suction and therapeutic capabilities, and keeping the procedural time as low and patient discomfort as optimal as possible.