Low-Cost High-Resolution Microendoscopy for the Detection of Esophageal Squamous Cell Neoplasia: An International Trial

Improving esophageal cancer screening across the globe: Translating knowledge into action

Esophageal cancer (EC) is a pressing global health concern, ranking as the eighth most common cancer and the sixth leading cause for cancer-related deaths worldwide. Esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) are the two major histological types of esophageal cancer associated with distinct risk factors and geographical distributions. Unfortunately, the outcomes for both types of EC remain discouraging, with a five-year survival rate of less than 20% when diagnosed at advanced stages. Advanced endoscopic techniques have the potential to vastly enhance patient outcomes and impede the progression of pre-malignant lesions to cancer. However, low screening rates with endoscopy due to its invasive nature and high cost hinder its effectiveness. Despite extensive research on risk predictors, a significant number of cases still go undiagnosed, highlighting the need for improved screening techniques that can be implemented at the population level. To increase uptake, a shift towards minimally invasive, well-tolerated and cost-effective non-endoscopic technologies is crucial. The implementation of such devices in primary care settings, specifically targeting high-risk populations, can be a promising strategy. With early detection and enrollment in surveillance programs, there is hope for substantial improvement in morbidity and mortality rates through modern minimally invasive endoscopic and surgical techniques.

Use of topical methylene blue to image nuclear morphometry with a low-cost scanning darkfield microendoscope

Significance

Fiber-optic microendoscopy is a promising approach to noninvasively visualize epithelial nuclear morphometry for early cancer and precancer detection. However, the broader clinical application of this approach is limited by a lack of topical contrast agents available for in vivo use.

Aim

The aim of this study was to evaluate the ability to image nuclear morphometry in vivo with a novel fiber-optic microendoscope used together with topical application of methylene blue (MB), a dye with FDA approval for use in chromoendoscopy in the gastrointestinal tract.

Approach

The low-cost, high-resolution microendoscope implements scanning darkfield imaging without complex optomechanical components by leveraging programmable illumination and the rolling shutter of the image sensor. We validate the integration of our system and MB staining for visualizing epithelial cell nuclei by performing ex vivo imaging on fresh animal specimens and in vivo imaging on healthy volunteers.

Results

The results indicate that scanning darkfield imaging significantly reduces specular reflection and resolves epithelial nuclei with enhanced image contrast and spatial resolution compared to non-scanning widefield imaging. The image quality of darkfield images with MB staining is comparable to that of fluorescence images with proflavine staining.

Conclusions

Our approach enables real-time microscopic evaluation of nuclear patterns and has the potential to be a powerful noninvasive tool for early cancer detection.

Deep-learning-based image super-resolution of an end-expandable optical fiber probe for application in esophageal cancer diagnostics

Significance

Endoscopic screening for esophageal cancer (EC) may enable early cancer diagnosis and treatment. While optical microendoscopic technology has shown promise in improving specificity, the limited field of view (< 1    mm ) significantly reduces the ability to survey large areas efficiently in EC screening.

Aim

To improve the efficiency of endoscopic screening, we propose a novel concept of end-expandable endoscopic optical fiber probe for larger field of visualization and for the first time evaluate a deep-learning-based image super-resolution (DL-SR) method to overcome the issue of limited sampling capability.

Approach

To demonstrate feasibility of the end-expandable optical fiber probe, DL-SR was applied on simulated low-resolution microendoscopic images to generate super-resolved (SR) ones. Varying the degradation model of image data acquisition, we identified the optimal parameters for optical fiber probe prototyping. The proposed screening method was validated with a human pathology reading study.

Results

For various degradation parameters considered, the DL-SR method demonstrated different levels of improvement of traditional measures of image quality. The endoscopists' interpretations of the SR images were comparable to those performed on the high-resolution ones.

Conclusions

This work suggests avenues for development of DL-SR-enabled sparse image reconstruction to improve high-yield EC screening and similar clinical applications.

Scanning darkfield high-resolution microendoscope for label-free microvascular imaging

Characterization of microvascular changes during neoplastic progression has the potential to assist in discriminating precancer and early cancer from benign lesions. Here, we introduce a novel high-resolution microendoscope that leverages scanning darkfield reflectance imaging to characterize angiogenesis without exogenous contrast agents. Scanning darkfield imaging is achieved by coupling programmable illumination with a complementary metal-oxide semiconductor (CMOS) camera rolling shutter, eliminating the need for complex optomechanical components and making the system portable, low-cost (<$5,500) and simple to use. Imaging depth is extended by placing a gradient-index (GRIN) lens at the distal end of the imaging fiber to resolve subepithelial microvasculature. We validated the capability of the scanning darkfield microendoscope to visualize microvasculature at different anatomic sites in vivo by imaging the oral cavity of healthy volunteers. Images of cervical specimens resected for suspected neoplasia reveal distinct microvascular patterns in columnar and squamous epithelium with different grades of precancer, indicating the potential of scanning darkfield microendoscopy to aid in efforts to prevent cervical cancer through early diagnosis.

Endoscopic Management of Esophageal Cancer

Advances in technology and improved understanding of the pathobiology of esophageal cancer have allowed endoscopy to serve a growing role in the management of this disease. Precursor lesions can be detected using enhanced diagnostic modalities and eradicated with ablation therapy. Furthermore, evolution in endoscopic resection has provided larger specimens for improved diagnostic accuracy and offer potential for cure of early esophageal cancer. In patients with advanced esophageal cancer, endoluminal therapy can improve symptom burden and provide therapeutic options for complications such as leaks, perforations, and fistulas. The purpose of this review article is to highlight the role of endoscopy in the diagnosis, treatment, and palliation of esophageal cancer.

Esophageal cancer: Epidemiology, risk factors and screening

More than 600,000 people are diagnosed with esophageal cancer (EC) every year globally, and the five-year survival rate of EC is less than 20%. Two common histological subtypes of EC, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), have great geographical variations in incidence rates. About half of the world's EC was diagnosed in China and a majority of which belong to ESCC. Globally, the overall incidence rate of EC is decreasing. In some high-risk Asian regions, such as China, the incidence rate of ESCC has generally declined, potentially due to economic growth and improvement of diet habits. In some European high-income countries and the United States, the decline is mainly attributed to the decrease in smoking and drinking. The risk factors of EC are not well understood, and the importance of environmental and genetic factors in the pathogenesis is also unclear. The incidence and mortality of advanced EC can be reduced through early diagnosis and screening. White light endoscopy is still the gold standard in the current screening technology. This article reviews the epidemiology, risk factors, and screening strategies of EC in recent years to help researchers determine the most effective management strategies to reduce the risk of EC.

Advances in optical gastrointestinal endoscopy: a technical review

Optical endoscopy is the primary diagnostic and therapeutic tool for management of gastrointestinal (GI) malignancies. Most GI neoplasms arise from precancerous lesions; thus, technical innovations to improve detection and diagnosis of precancerous lesions and early cancers play a pivotal role in improving outcomes. Over the last few decades, the field of GI endoscopy has witnessed enormous and focused efforts to develop and translate accurate, user-friendly, and minimally invasive optical imaging modalities. From a technical point of view, a wide range of novel optical techniques is now available to probe different aspects of light-tissue interaction at macroscopic and microscopic scales, complementing white light endoscopy. Most of these new modalities have been successfully validated and translated to routine clinical practice. Herein, we provide a technical review of the current status of existing and promising new optical endoscopic imaging technologies for GI cancer screening and surveillance. We summarize the underlying principles of light-tissue interaction, the imaging performance at different scales, and highlight what is known about clinical applicability and effectiveness. Furthermore, we discuss recent discovery and translation of novel molecular probes that have shown promise to augment endoscopists' ability to diagnose GI lesions with high specificity. We also review and discuss the role and potential clinical integration of artificial intelligence-based algorithms to provide decision support in real time. Finally, we provide perspectives on future technology development and its potential to transform endoscopic GI cancer detection and diagnosis.

High frame rate video mosaicking microendoscope to image large regions of intact tissue with subcellular resolution

High-resolution microendoscopy (HRME) is a low-cost strategy to acquire images of intact tissue with subcellular resolution at frame rates ranging from 11 to 18 fps. Current HRME imaging strategies are limited by the small microendoscope field of view (∼0.5 mm2); multiple images must be acquired and reliably registered to assess large regions of clinical interest. Image mosaics have been assembled from co-registered frames of video acquired as a microendoscope is slowly moved across the tissue surface, but the slow frame rate of previous HRME systems made this approach impractical for acquiring quality mosaicked images from large regions of interest. Here, we present a novel video mosaicking microendoscope incorporating a high frame rate CMOS sensor and optical probe holder to enable high-speed, high quality interrogation of large tissue regions of interest. Microendoscopy videos acquired at >90 fps are assembled into an image mosaic. We assessed registration accuracy and image sharpness across the mosaic for images acquired with a handheld probe over a range of translational speeds. This high frame rate video mosaicking microendoscope enables in vivo probe translation at >15 millimeters per second while preserving high image quality and accurate mosaicking, increasing the size of the region of interest that can be interrogated at high resolution from 0.5 mm2 to >30 mm2. Real-time deployment of this high-frame rate system is demonstrated in vivo and source code made publicly available.

Automated software-assisted diagnosis of esophageal squamous cell neoplasia using high-resolution microendoscopy

BACKGROUND AND AIMS

High-resolution microendoscopy (HRME) is an optical biopsy technology that provides subcellular imaging of esophageal mucosa but requires expert interpretation of these histopathology-like images. We compared endoscopists with an automated software algorithm for detection of esophageal squamous cell neoplasia (ESCN) and evaluated the endoscopists' accuracy with and without input from the software algorithm.

METHODS

Thirteen endoscopists (6 experts, 7 novices) were trained and tested on 218 post-hoc HRME images from 130 consecutive patients undergoing ESCN screening/surveillance. The automated software algorithm interpreted all images as neoplastic (high-grade dysplasia, ESCN) or non-neoplastic. All endoscopists provided their interpretation (neoplastic or non-neoplastic) and confidence level (high or low) without and with knowledge of the software overlay highlighting abnormal nuclei and software interpretation. The criterion standard was histopathology consensus diagnosis by 2 pathologists.

RESULTS

The endoscopists had a higher mean sensitivity (84.3%, standard deviation [SD] 8.0% vs 76.3%, P = .004), lower specificity (75.0%, SD 5.2% vs 85.3%, P < .001) but no significant difference in accuracy (81.1%, SD 5.2% vs 79.4%, P = .26) of ESCN detection compared with the automated software algorithm. With knowledge of the software algorithm, the specificity of the endoscopists increased significantly (75.0% to 80.1%, P = .002) but not the sensitivity (84.3% to 84.8%, P = .75) or accuracy (81.1% to 83.1%, P = .13). The increase in specificity was among novices (P = .008) but not experts (P = .11).

CONCLUSIONS

The software algorithm had lower sensitivity but higher specificity for ESCN detection than endoscopists. Using computer-assisted diagnosis, the endoscopists maintained high sensitivity while increasing their specificity and accuracy compared with their initial diagnosis. Automated HRME interpretation would facilitate widespread usage in resource-poor areas where this portable, low-cost technology is needed.

The Value of Virtual Chromoendoscopy in the Workup of Patients with Head and Neck Squamous Cell Carcinoma

PURPOSE OF REVIEW

Second primary tumors (SPTs) significantly increase the mortality in patients with head and neck squamous cell carcinomas (HNSCCs). Virtual chromoendoscopy (VCE) could complement or replace lugol chromoendoscopy (LCE) for early esophageal second primary tumor (ESPT) detection. An overview of the existing techniques and their diagnostic performance in early detection of esophageal squamous cell neoplasms is provided.

RECENT FINDINGS

Nowadays, LCE is the golden standard to detect ESPTs. Recently, multiple new VCE techniques have been developed. Especially narrow-band imaging (NBI) is promising. It shows similar sensitivity to LCE, but a significantly higher specificity. Patients with HNSCC are prone to develop ESPTs, both synchronous and metachronous, with a substantial negative impact on survival rates. Therefore, active screening and follow-up is necessary. LCE is an effective screening method, but has some disadvantages. Countering these drawbacks, NBI shows a high potential in early ESPT detection in high-risk patients. Additional multicenter studies are needed to compare diagnostic performance and cost-effectiveness of NBI and other VCE techniques with LCE.

Artificial intelligence-assisted esophageal cancer management: Now and future

Esophageal cancer poses diagnostic, therapeutic and economic burdens in high-risk regions. Artificial intelligence (AI) has been developed for diagnosis and outcome prediction using various features, including clinicopathologic, radiologic, and genetic variables, which can achieve inspiring results. One of the most recent tasks of AI is to use state-of-the-art deep learning technique to detect both early esophageal squamous cell carcinoma and esophageal adenocarcinoma in Barrett’s esophagus. In this review, we aim to provide a comprehensive overview of the ways in which AI may help physicians diagnose advanced cancer and make clinical decisions based on predicted outcomes, and combine the endoscopic images to detect precancerous lesions or early cancer. Pertinent studies conducted in recent two years have surged in numbers, with large datasets and external validation from multi-centers, and have partly achieved intriguing results of expert’s performance of AI in real time. Improved pre-trained computer-aided diagnosis algorithms in the future studies with larger training and external validation datasets, aiming at real-time video processing, are imperative to produce a diagnostic efficacy similar to or even superior to experienced endoscopists. Meanwhile, supervised randomized controlled trials in real clinical practice are highly essential for a solid conclusion, which meets patient-centered satisfaction. Notably, ethical and legal issues regarding the black-box nature of computer algorithms should be addressed, for both clinicians and regulators.

Surgical margins in oral cavity squamous cell carcinoma: Current practices and future directions

OBJECTIVE

To discuss the current available techniques for intraoperative margin assessment in the surgical treatment of oral squamous cell carcinoma (OSCC) through a review of the available literature.

METHODS

A systematic review was undertaken of the available English literature between 2008 through 2018 regarding surgical margins in OCSS. A total of 893 relevant articles were returned; 144 met criteria for review; and 64 articles were included.

RESULTS

In this review, we discuss the data surrounding the use of frozen section in OCSS. Additionally, alternative techniques for margin assessment are discussed, including Mohs, molecular analysis, nonfluorescent dyes, fluorescent dyes, autofluorescent imaging, narrow-band imaging, optical coherence tomography, confocal microscopy, high-resolution microendoscopy, and spectroscopy. For each technique, particular emphasis is placed on the local recurrence, disease-free survival, and overall survival rates when available.

CONCLUSION

This review provides support for the practice of specimen-driven margin assessment when using frozen section analysis to improve the utility of the results. Finally, several alternatives for intraoperative margin assessment currently under investigation, including pathologic, wide-field imaging and narrow-field imaging techniques, are presented. We aim to fuel further investigation into methods for margin assessment that will improve survival for patients with OSCC through a critical analysis of the available techniques.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:128-138, 2020.

Screening for esophageal squamous cell carcinoma: recent advances

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer worldwide, with a high mortality due to advanced stage at diagnosis. Although most common in an area known as the Asian Esophageal Cancer Belt, which extends from the Caspian Sea to northern China, and in parts of Africa, high-risk populations also exist elsewhere in the world. Screening for ESCC has been practiced in a few geographic areas and high-risk populations, with varying levels of success. Esophageal squamous dysplasia is recognized as the precursor lesion for ESCC. Endoscopic screening for ESCC/esophageal squamous dysplasia is expensive and not sufficiently available in many high-risk regions. Recent advances in non-endoscopic screening enhanced by biomarker-based disease detection have raised the prospect of improved accuracy and availability of screening for esophageal squamous dysplasia and early stage ESCC. Development of a cost-effective, accurate, and well-tolerated screening test, if applied in endemic areas and high-risk populations, has the potential to reduce mortality from this deadly disease worldwide. In this review, we summarize recent developments in endoscopic and non-endoscopic screening modalities.

Is Proflavine Exposure Associated with Disease Progression in Women with Cervical Dysplasia? A Brief Report

Proflavine is an acridine dye used with high-resolution microendoscopy for in vivo diagnostic evaluation of cervical epithelial cells. However, there are concerns that even short-term exposure of cervical tissue to dilute proflavine may increase cervical cancer risk. We performed a retrospective analysis of women referred for colposcopy to Barretos Cancer Hospital comparing the risk of cervical disease progression in those whose cervical tissue was (n = 232) or was not exposed (n = 160) to proflavine. Patients in both groups underwent treatment and follow-up based on histopathologic results and per the local standards of care. Progression of disease was evaluated by comparing histopathology from the initial visit to the worst subsequent histopathology result from all follow-up visits. Mean duration of follow-up was 18.7 and 20.1 months for the proflavine-exposed and controls groups, respectively. There were no significant differences in disease progression from normal/CIN1 to CIN2/3 or from any initial diagnosis to invasive cancer between the proflavine exposed and control groups overall. Risks of cervical dysplasia progression observed in this study are in agreement with those of the natural history of cervical cancer. Our results suggest that cervical exposure to dilute proflavine does not increase the risk of cervical precancer and cancer.

Fluorescence Imaging for Cancer Screening and Surveillance

The advent of fluorescence imaging (FI) for cancer cell detection in the field of oncology is promising for both cancer screening and surgical resection. Particularly, FI in cancer screening and surveillance is actively being evaluated in many new clinical trials with over 30 listed on Clinical Trials.gov . While surgical resection forms the foundation of many oncologic treatments, early detection is the cornerstone for improving outcomes and reducing cancer-related morbidity and mortality. The applications of FI are twofold as it can be applied to high-risk patients in addition to those undergoing active surveillance. This technology has the promise of highlighting lesions not readily detected by conventional imaging or physical examination, allowing disease detection at an earlier stage of development. Additionally, there is a persistent need for innovative, cost-effective imaging modalities to ameliorate healthcare disparities and the global burden of cancer worldwide. In this review, we outline the current utility of FI for screening and detection in a range of cancer types.

Diagnosing Cervical Neoplasia in Rural Brazil Using a Mobile Van Equipped with In Vivo Microscopy: A Cluster-Randomized Community Trial

Cervical cancer is a leading cause of death in underserved areas of Brazil. This prospective randomized trial involved 200 women in southern/central Brazil with abnormal Papanicolaou tests. Participants were randomized by geographic cluster and referred for diagnostic evaluation either at a mobile van upon its scheduled visit to their local community, or at a central hospital. Participants in both arms underwent colposcopy, in vivo microscopy, and cervical biopsies. We compared rates of diagnostic follow-up completion between study arms, and also evaluated the diagnostic performance of in vivo microscopy compared with colposcopy. There was a 23% absolute and 37% relative increase in diagnostic follow-up completion rates for patients referred to the mobile van (102/117, 87%) compared with the central hospital (53/83, 64%; P = 0.0001; risk ratio = 1.37, 95% CI, 1.14-1.63). In 229 cervical sites in 144 patients, colposcopic examination identified sites diagnosed as cervical intraepithelial neoplasia grade 2 or more severe (CIN2+; 85 sites) with a sensitivity of 94% (95% CI, 87%-98%) and specificity of 50% (95% CI, 42%-58%). In vivo microscopy with real-time automated image analysis identified CIN2+ with a sensitivity of 92% (95% CI, 84%-97%) and specificity of 48% (95% CI, 40%-56%). Women referred to the mobile van were more likely to complete their diagnostic follow-up compared with those referred to a central hospital, without compromise in clinical care. In vivo microscopy in a mobile van provides automated diagnostic imaging with sensitivity and specificity similar to colposcopy. Cancer Prev Res; 11(6); 359-70. ©2018 AACR.

In-vivo optical imaging in head and neck oncology: basic principles, clinical applications and future directions

Head and neck cancers become a severe threat to human's health nowadays and represent the sixth most common cancer worldwide. Surgery remains the first-line choice for head and neck cancer patients. Limited resectable tissue mass and complicated anatomy structures in the head and neck region put the surgeons in a dilemma between the extensive resection and a better quality of life for the patients. Early diagnosis and treatment of the pre-malignancies, as well as real-time in vivo detection of surgical margins during en bloc resection, could be leveraged to minimize the resection of normal tissues. With the understanding of the head and neck oncology, recent advances in optical hardware and reagents have provided unique opportunities for real-time pre-malignancies and cancer imaging in the clinic or operating room. Optical imaging in the head and neck has been reported using autofluorescence imaging, targeted fluorescence imaging, high-resolution microendoscopy, narrow band imaging and the Raman spectroscopy. In this study, we reviewed the basic theories and clinical applications of optical imaging for the diagnosis and treatment in the field of head and neck oncology with the goal of identifying limitations and facilitating future advancements in the field.

The Role of Affordable, Point-of-Care Technologies for Cancer Care in Low- and Middle-Income Countries: A Review and Commentary

As the burden of non-communicable diseases such as cancer continues to rise in low- and middle-income countries (LMICs), it is essential to identify and invest in promising solutions for cancer control and treatment. Point-of-care technologies (POCTs) have played critical roles in curbing infectious disease epidemics in both high- and low-income settings, and their successes can serve as a model for transforming cancer care in LMICs, where access to traditional clinical resources is often limited. The versatility, cost-effectiveness, and simplicity of POCTs warrant attention for their potential to revolutionize cancer detection, diagnosis, and treatment. This paper reviews the landscape of affordable POCTs for cancer care in LMICs with a focus on imaging tools, in vitro diagnostics, and treatment technologies and aspires to encourage innovation and further investment in this space.

Prospective Evaluation of Multimodal Optical Imaging with Automated Image Analysis to Detect Oral Neoplasia In Vivo

The 5-year survival rate for patients with oral cancer remains low, in part because diagnosis often occurs at a late stage. Early and accurate identification of oral high-grade dysplasia and cancer can help improve patient outcomes. Multimodal optical imaging is an adjunctive diagnostic technique in which autofluorescence imaging is used to identify high-risk regions within the oral cavity, followed by high-resolution microendoscopy to confirm or rule out the presence of neoplasia. Multimodal optical images were obtained from 206 sites in 100 patients. Histologic diagnosis, either from a punch biopsy or an excised surgical specimen, was used as the gold standard for all sites. Histopathologic diagnoses of moderate dysplasia or worse were considered neoplastic. Images from 92 sites in the first 30 patients were used as a training set to develop automated image analysis methods for identification of neoplasia. Diagnostic performance was evaluated prospectively using images from 114 sites in the remaining 70 patients as a test set. In the training set, multimodal optical imaging with automated image analysis correctly classified 95% of nonneoplastic sites and 94% of neoplastic sites. Among the 56 sites in the test set that were biopsied, multimodal optical imaging correctly classified 100% of nonneoplastic sites and 85% of neoplastic sites. Among the 58 sites in the test set that corresponded to a surgical specimen, multimodal imaging correctly classified 100% of nonneoplastic sites and 61% of neoplastic sites. These findings support the potential of multimodal optical imaging to aid in the early detection of oral cancer. Cancer Prev Res; 10(10); 563-70. ©2017 AACR.

A tablet-interfaced high-resolution microendoscope with automated image interpretation for real-time evaluation of esophageal squamous cell neoplasia

BACKGROUND AND AIMS

In recent years high-resolution microendoscopy (HRME) has shown potential to improve screening for esophageal squamous cell neoplasia. Furthering its utility in a clinical setting, especially in lower-resource settings, could be accomplished by reducing the size and cost of the system as well as incorporating the ability of real-time, objective feedback. This article describes a tablet-interfaced HRME with fully automated, real-time image analysis.

METHODS

The performance of the tablet-interfaced HRME was assessed by acquiring images from the oral mucosa in a normal volunteer. An automated, real-time analysis algorithm was developed and evaluated using training, test, and validation images from a previous in vivo study of 177 patients referred for screening or surveillance endoscopy in China. The algorithm was then implemented in a tablet HRME that was used to obtain and analyze images from esophageal tissue in 3 patients. Images were displayed alongside the probability that the imaged region was neoplastic.

RESULTS

The tablet-interfaced HRME demonstrated comparable imaging performance at a lower cost compared with first-generation laptop-interfaced HRME systems. In a post-hoc quantitative analysis, the algorithm identified neoplasia with a sensitivity and specificity of 95% and 91%, respectively, in the validation set compared with 84% and 95% achieved in the original study.

CONCLUSIONS

The tablet-based HRME is a low-cost tool that provides quantitative diagnostic information to the endoscopist in real time. This could be especially beneficial in lower-resource settings for operators with less experience interpreting HRME images.

Early esophageal cancer screening in China

In China, the incidence of esophageal cancer (EC) and its related mortality are high. Screening strategies aiming at early diagnosis can improve the prognosis. Researches on detection of early EC, especially in China are reviewed. Compared to esophageal balloon cytology or routine endoscopy, chromoendoscopy with Lugol's staining and biopsy appears to be the gold standard for early EC diagnosis in China today. Narrow-band imaging endoscopy, Confocal Laser endomicroscopy and other novel diagnostic approaches are more and more widely used in developed urban areas, but cost and lack of essential training to the endoscopists have made their use limited in rural areas. No specific biomarkers or serum markers were strongly commended to be used in screening strategies currently, which need to be evaluated in future. Trials on organized screening have been proposed in some regions of china with high disease prevalence. Screening in these areas has been shown to be cost effective.