Colorectal cancer (CRC) is the third cause of cancer death worldwide. Currently, the standard approach to reduce CRC-related mortality is to perform regular screening in search for polyps and colonoscopy is the screening tool of choice. The main limitations of this screening procedure are polyp miss rate and the inability to perform visual assessment of polyp malignancy. These drawbacks can be reduced by designing decision support systems (DSS) aiming to help clinicians in the different stages of the procedure by providing endoluminal scene segmentation. Thus, in this paper, we introduce an extended benchmark of colonoscopy image segmentation, with the hope of establishing a new strong benchmark for colonoscopy image analysis research. The proposed dataset consists of 4 relevant classes to inspect the endoluminal scene, targeting different clinical needs. Together with the dataset and taking advantage of advances in semantic segmentation literature, we provide new baselines by training standard fully convolutional networks (FCNs). We perform a comparative study to show that FCNs significantly outperform, without any further postprocessing, prior results in endoluminal scene segmentation, especially with respect to polyp segmentation and localization.

Colonoscopy is the gold standard for colon cancer screening though some polyps are still missed, thus preventing early disease detection and treatment. Several computational systems have been proposed to assist polyp detection during colonoscopy but so far without consistent evaluation. The lack of publicly available annotated databases has made it difficult to compare methods and to assess if they achieve performance levels acceptable for clinical use. The Automatic Polyp Detection sub-challenge, conducted as part of the Endoscopic Vision Challenge (http://endovis.grand-challenge.org) at the international conference on Medical Image Computing and Computer Assisted Intervention (MICCAI) in 2015, was an effort to address this need. In this paper, we report the results of this comparative evaluation of polyp detection methods, as well as describe additional experiments to further explore differences between methods. We define performance metrics and provide evaluation databases that allow comparison of multiple methodologies. Results show that convolutional neural networks are the state of the art. Nevertheless, it is also demonstrated that combining different methodologies can lead to an improved overall performance.

RECOMMENDATIONS: For routine EUS-guided sampling of solid masses and lymph nodes (LNs) ESGE recommends 25G or 22G needles (high quality evidence, strong recommendation); fine needle aspiration (FNA) and fine needle biopsy (FNB) needles are equally recommended (high quality evidence, strong recommendation).When the primary aim of sampling is to obtain a core tissue specimen, ESGE suggests using 19G FNA or FNB needles or 22G FNB needles (low quality evidence, weak recommendation).ESGE recommends using 10-mL syringe suction for EUS-guided sampling of solid masses and LNs with 25G or 22G FNA needles (high quality evidence, strong recommendation) and other types of needles (low quality evidence, weak recommendation). ESGE suggests neutralizing residual negative pressure in the needle before withdrawing the needle from the target lesion (moderate quality evidence, weak recommendation).ESGE does not recommend for or against using the needle stylet for EUS-guided sampling of solid masses and LNs with FNA needles (high quality evidence, strong recommendation) and suggests using the needle stylet for EUS-guided sampling with FNB needles (low quality evidence, weak recommendation).ESGE suggests fanning the needle throughout the lesion when sampling solid masses and LNs (moderate quality evidence, weak recommendation).ESGE equally recommends EUS-guided sampling with or without on-site cytologic evaluation (moderate quality evidence, strong recommendation). When on-site cytologic evaluation is unavailable, ESGE suggests performance of three to four needle passes with an FNA needle or two to three passes with an FNB needle (low quality evidence, weak recommendation).For diagnostic sampling of pancreatic cystic lesions without a solid component, ESGE suggests emptying the cyst with a single pass of a 22G or 19G needle (low quality evidence, weak recommendation). For pancreatic cystic lesions with a solid component, ESGE suggests sampling of the solid component using the same technique as in the case of other solid lesions (low quality evidence, weak recommendation).ESGE does not recommend antibiotic prophylaxis for EUS-guided sampling of solid masses or LNs (low quality evidence, strong recommendation), and suggests antibiotic prophylaxis with fluoroquinolones or beta-lactam antibiotics for EUS-guided sampling of cystic lesions (low quality evidence, weak recommendation). ESGE suggests that evaluation of tissue obtained by EUS-guided sampling should include histologic preparations (e. g., cell blocks and/or formalin-fixed and paraffin-embedded tissue fragments) and should not be limited to smear cytology (low quality evidence, weak recommendation).

MAIN RECOMMENDATIONS: For pancreatic solid lesions, ESGE recommends performing endoscopic ultrasound (EUS)-guided sampling as first-line procedure when a pathological diagnosis is required. Alternatively, percutaneous sampling may be considered in metastatic disease.Strong recommendation, moderate quality evidence.In the case of negative or inconclusive results and a high degree of suspicion of malignant disease, ESGE suggests re-evaluating the pathology slides, repeating EUS-guided sampling, or surgery.Weak recommendation, low quality evidence.In patients with chronic pancreatitis associated with a pancreatic mass, EUS-guided sampling results that do not confirm cancer should be interpreted with caution.Strong recommendation, low quality evidence.For pancreatic cystic lesions (PCLs), ESGE recommends EUS-guided sampling for biochemical analyses plus cytopathological examination if a precise diagnosis may change patient management, except for lesions ≤ 10 mm in diameter with no high risk stigmata. If the volume of PCL aspirate is small, it is recommended that carcinoembryonic antigen (CEA) level determination be done as the first analysis.Strong recommendation, low quality evidence.For esophageal cancer, ESGE suggests performing EUS-guided sampling for the assessment of regional lymph nodes (LNs) in T1 (and, depending on local treatment policy, T2) adenocarcinoma and of lesions suspicious for metastasis such as distant LNs, left liver lobe lesions, and suspected peritoneal carcinomatosis.Weak recommendation, low quality evidence.For lymphadenopathy of unknown origin, ESGE recommends performing EUS-guided (or alternatively endobronchial ultrasound [EBUS]-guided) sampling if the pathological result is likely to affect patient management and no superficial lymphadenopathy is easily accessible.Strong recommendation, moderate quality evidence.In the case of solid liver masses suspicious for metastasis, ESGE suggests performing EUS-guided sampling if the pathological result is likely to affect patient management, and (i) the lesion is poorly accessible/not detected at percutaneous imaging, or (ii) a sample obtained via the percutaneous route repeatedly yielded an inconclusive result.Weak recommendation, low quality evidence.

Main Recommendations: At a population level, the European Society of Gastrointestinal Endoscopy (ESGE), the European Helicobacter and Microbiota Study Group (EHMSG), and the European Society of Pathology (ESP) suggest endoscopic screening for gastric cancer (and precancerous conditions) in high-risk regions (age-standardized rate [ASR] > 20 per 100 000 person-years) every 2 to 3 years or, if cost–effectiveness has been proven, in intermediate risk regions (ASR 10–20 per 100 000 person-years) every 5 years, but not in low-risk regions (ASR < 10).ESGE/EHMSG/ESP recommend that irrespective of country of origin, individual gastric risk assessment and stratification of precancerous conditions is recommended for first-time gastroscopy. ESGE/EHMSG/ESP suggest that gastric cancer screening or surveillance in asymptomatic individuals over 80 should be discontinued or not started, and that patients’ comorbidities should be considered when treatment of superficial lesions is planned.ESGE/EHMSG/ESP recommend that a high quality endoscopy including the use of virtual chromoendoscopy (VCE), after proper training, is performed for screening, diagnosis, and staging of precancerous conditions (atrophy and intestinal metaplasia) and lesions (dysplasia or cancer), as well as after endoscopic therapy. VCE should be used to guide the sampling site for biopsies in the case of suspected neoplastic lesions as well as to guide biopsies for diagnosis and staging of gastric precancerous conditions, with random biopsies to be taken in the absence of endoscopically suspected changes. When there is a suspected early gastric neoplastic lesion, it should be properly described (location, size, Paris classification, vascular and mucosal pattern), photodocumented, and two targeted biopsies taken.ESGE/EHMSG/ESP do not recommend routine performance of endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT prior to endoscopic resection unless there are signs of deep submucosal invasion or if the lesion is not considered suitable for endoscopic resection.ESGE/EHMSG/ESP recommend endoscopic submucosal dissection (ESD) for differentiated gastric lesions clinically staged as dysplastic (low grade and high grade) or as intramucosal carcinoma (of any size if not ulcerated or ≤ 30 mm if ulcerated), with EMR being an alternative for Paris 0-IIa lesions of size ≤ 10 mm with low likelihood of malignancy.ESGE/EHMSG/ESP suggest that a decision about ESD can be considered for malignant lesions clinically staged as having minimal submucosal invasion if differentiated and ≤ 30 mm; or for malignant lesions clinically staged as intramucosal, undifferentiated and ≤ 20 mm; and in both cases with no ulcerative findings.ESGE/EHMSG/ESP recommends patient management based on the following histological risk after endoscopic resection: Curative/very low-risk resection (lymph node metastasis [LNM] risk < 0.5 %–1 %): en bloc R0 resection; dysplastic/pT1a, differentiated lesion, no lymphovascular invasion, independent of size if no ulceration and ≤ 30 mm if ulcerated. No further staging procedure or treatment is recommended.Curative/low-risk resection (LNM risk < 3 %): en bloc R0 resection; lesion with no lymphovascular invasion and: a) pT1b, invasion ≤ 500 µm, differentiated, size ≤ 30 mm; or b) pT1a, undifferentiated, size ≤ 20 mm and no ulceration. Staging should be completed, and further treatment is generally not necessary, but a multidisciplinary discussion is required. Local-risk resection (very low risk of LNM but increased risk of local persistence/recurrence): Piecemeal resection or tumor-positive horizontal margin of a lesion otherwise meeting curative/very low-risk criteria (or meeting low-risk criteria provided that there is no submucosal invasive tumor at the resection margin in the case of piecemeal resection or tumor-positive horizontal margin for pT1b lesions [invasion ≤ 500 µm; well-differentiated; size ≤ 30 mm, and VM0]). Endoscopic surveillance/re-treatment is recommended rather than other additional treatment. High-risk resection (noncurative): Any lesion with any of the following: (a) a positive vertical margin (if carcinoma) or lymphovascular invasion or deep submucosal invasion (> 500 µm from the muscularis mucosae); (b) poorly differentiated lesions if ulceration or size > 20 mm; (c) pT1b differentiated lesions with submucosal invasion ≤ 500 µm with size > 30 mm; or (d) intramucosal ulcerative lesion with size > 30 mm. Complete staging and strong consideration for additional treatments (surgery) in multidisciplinary discussion.ESGE/EHMSG/ESP suggest the use of validated endoscopic classifications of atrophy (e. g. Kimura–Takemoto) or intestinal metaplasia (e. g. endoscopic grading of gastric intestinal metaplasia [EGGIM]) to endoscopically stage precancerous conditions and stratify the risk for gastric cancer.ESGE/EHMSG/ESP recommend that biopsies should be taken from at least two topographic sites (2 biopsies from the antrum/incisura and 2 from the corpus, guided by VCE) in two separate, clearly labeled vials. Additional biopsy from the incisura is optional.ESGE/EHMSG/ESP recommend that patients with extensive endoscopic changes (Kimura C3 + or EGGIM 5 +) or advanced histological stages of atrophic gastritis (severe atrophic changes or intestinal metaplasia, or changes in both antrum and corpus, operative link on gastritis assessment/operative link on gastric intestinal metaplasia [OLGA/OLGIM] III/IV) should be followed up with high quality endoscopy every 3 years, irrespective of the individual’s country of origin.ESGE/EHMSG/ESP recommend that no surveillance is proposed for patients with mild to moderate atrophy or intestinal metaplasia restricted to the antrum, in the absence of endoscopic signs...