Long-term outcome after endoscopic mucosal resection in patients with esophageal squamous cell carcinoma invading the muscularis mucosae or deeper

High incidence of lung cancer death after curative endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma

BACKGROUND AND AIM

Following treatment of superficial esophageal squamous cell carcinoma (ESCC), surveillance for a second primary malignancy (SPM) is necessary. However, detailed evidence regarding the timing and prognosis of SPMs is insufficient. We aimed to clarify the details of SPMs and their effects on patient outcomes.

METHODS

This retrospective, multicenter study involved 11 hospitals. Patients with superficial ESCC curatively resected using endoscopic submucosal dissection between May 2005 and December 2012, were included in this study.

RESULTS

The 5-year survival rate of 187 patients was 92.6% during a median follow-up duration of 96.8 months. Thirty-one patients died, 14 of whom died of SPMs. Compared to patients with SPMs detectable by esophagogastroduodenoscopy (EGD), patients with SPMs detectable only by modalities other than EGD had a significantly higher mortality rate (p < 0.001). Patients with second primary lung cancer (LC) had a high mortality rate (56.3%). Univariate and multivariate analyses showed that multiple Lugol-voiding lesions (LVLs) tended to be associated with SPMs (p = 0.077, hazard ratio [HR] 4.43, 95% confidence interval [CI]: 0.91-6.50), and metachronous ESCC was an independent risk factor for the incidence of second primary LC (p = 0.037, HR 3.51, 95% CI: 1.08-11.41).

CONCLUSIONS

SPMs that cannot be detected by EGD, such as LC, must be considered after the curative resection of ESCC. We suggest strict screening by both EGD and computed tomography for patients with multiple LVLs or metachronous ESCC to detect SPMs in their early stages.

Application of the convolution neural network in determining the depth of invasion of gastrointestinal cancer: a systematic review and meta-analysis

BACKGROUND

With the development of endoscopic technology, endoscopic submucosal dissection (ESD) has been widely used in the treatment of gastrointestinal tumors. It is necessary to evaluate the depth of tumor invasion before the application of ESD. The convolution neural network (CNN) is a type of artificial intelligence that has the potential to assist in the classification of the depth of invasion in endoscopic images. This meta-analysis aimed to evaluate the performance of CNN in determining the depth of invasion of gastrointestinal tumors.

METHODS

A search on PubMed, Web of Science, and SinoMed was performed to collect the original publications about the use of CNN in determining the depth of invasion of gastrointestinal neoplasms. Pooled sensitivity and specificity were calculated using an exact binominal rendition of the bivariate mixed-effects regression model. I2 was used for the evaluation of heterogeneity.

RESULTS

A total of 17 articles were included; the pooled sensitivity was 84% (95% CI, 0.81-0.88), specificity was 91% (95% CI, 0.85-0.94), and the area under the curve (AUC) was 0.93 (95% CI, 0.90-0.95). The performance of CNN was significantly better than that of endoscopists (AUC: 0.93 vs 0.83, respectively; P = .0005).

CONCLUSION

Our review revealed that CNN is one of the most effective methods of endoscopy to evaluate the depth of invasion of early gastrointestinal tumors, which has the potential to work as a remarkable tool for clinical endoscopists to make decisions on whether the lesion is feasible for endoscopic treatment.

Association between continuous cessation or reduction of drinking alcohol and improvement of multiple dysplastic lesions in patients with esophageal squamous cell carcinoma after endoscopic resection

BACKGROUND

Multiple development of squamous cell carcinoma (SCC) in the upper aerodigestive tract has been explained by the 'field cancerization phenomenon' associated with alcohol drinking. Squamous dysplastic lesion is clinically visualised as a Lugol-voiding lesion (LVL) by chromoendoscopy. Whether cessation or reduction of alcohol drinking improves multiple LVL and reduces the risk of field cancerization has not been elucidated.

METHODS

We analysed 330 patients with newly diagnosed superficial esophageal SCC (ESCC) enrolled in the cohort study. The grade of LVL was assessed in all patients every 6 months. We instructed the patients to stop smoking and drinking and recorded their drinking and smoking status every 6 months.

RESULTS

Among 330 patients, we excluded 98 with no LVL or no drinking habit. Of the remaining 232 patients, 158 continuously ceased or reduced their drinking habit. Patients who ceased or reduced their drinking habit significantly showed improvement in the grade of LVL. Multivariate analysis showed that continuous cessation or reduction of drinking habit improved the grade of LVL (hazard ratio [HR] = 8.5, 95% confidence interval [CI] 1.7-153.8, p = 0.0053). Higher grade of LVL carried a high risk of multiple ESCC and head and neck SCC (HNSCC) (HR = 3.7, 95% CI 2.2-6.4, p < 0.0001). Improvement in LVL significantly decreased the risk of multiple ESCC and HNSCC (HR = 0.2, 95% CI 0.04-0.7, p = 0.009).

CONCLUSIONS

This is the first report indicating that field cancerization was reversible and cessation or reduction of drinking alcohol could prevent multiple squamous dysplastic lesion and multiple ESCC and HNSCC development.

CLINICAL TRIALS REGISTRY NUMBER

UMIN000001676.

Diagnostic Performance of Endoscopic Ultrasonography with Water-Filled Balloon Method for Superficial Esophageal Squamous Cell Carcinoma

BACKGROUND

Endoscopic ultrasonography (EUS) is a commonly used tool for preoperative depth diagnosis of superficial esophageal squamous cell carcinoma (ESCC). Probing EUS using the water-filled balloon method is a simple and safe examination.

AIM

The aim of this study was to clarify the diagnostic performance of EUS with the water-filled balloon method for superficial ESCC compared to magnifying narrow-band imaging (ME-NBI).

METHODS

We retrospectively examined 403 lesions in 393 consecutive patients diagnosed with ESCC and evaluated them with ME-NBI and EUS. Clinicopathological findings were collected, and the accuracy of the preoperative diagnosis was compared between ME-NBI and EUS-B. EUS examiners were not blinded to prior ME-NBI results, and EUS results may have been influenced by ME-NBI results.

RESULTS

The pathological tumor depth of the EP/LPM in 152 lesions, MM/SM1 in 130 lesions, and deep submucosa (SM2/SM3) in 121 lesions was examined. The proportion of total lesions with an accurate diagnosis was significantly higher in EUS than in ME-NBI (67.7% versus 62.0%, P = 0.015). When analyzed by clinical depth diagnosis using ME-NBI, the proportion of lesions with an accurate diagnosis was significantly higher for EUS in MM/SM1 (55.7% versus 46.1%, P = 0.033). The sensitivity was significantly higher in EUS for SM2/SM3 lesions (76.0% versus 54.5%, P < 0.001). The accuracy and specificity of EUS, which differentiate MM/SM1 from EP/LPM or SM2/SM3, were significantly higher than those of ME-NBI. The median endoscopic ultrasonography procedure time was approximately 6.5 min.

CONCLUSIONS

EUS with the water-filled balloon method is a safe and straightforward method that can be performed on lesions clinically diagnosed as MM/SM1 using ME-NBI. We retrospectively reviewed lesions in patients diagnosed with ESCC and evaluated them using magnifying endoscopy with narrow-band imaging (ME-NBI) and endoscopic ultrasound using the water-filled balloon method (EUS-B). We conclude that EUS-B can increase the diagnostic accuracy.

Clinical Outcomes of Follow-Up Observation After Endoscopic Submucosal Dissection for Esophageal Squamous Cell Carcinoma Invading the Muscularis Mucosa Without Lymphovascular Involvement

BACKGROUND

The therapeutic approach after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) diagnosed as pathological T1a-muscularis mucosa (pT1a-MM) without lymphovascular involvement (LVI) remains uncertain. We aimed to determine whether observation after ESD is acceptable for patients without LVI showing pT1a-MM cancer.

METHODS

We retrospectively registered 566 ESCC patients who were treated with ESD at ten institutions between January 2007 and December 2015. Of those, 447 cases showing pT1a-epithelium/lamina propria mucosa (EP/LPM) without LVI and vertical margin (VM) (EP/LPM group), and 41 cases showing pT1a-MM without LVI and VM (MM group) were analyzed in this investigation. The clinical outcomes were assessed between the groups.

RESULTS

The 5 year cumulative incidence of metastatic recurrence was 0.5% and 3.3% in the EP/LPM and MM groups, respectively (P = 0.121). Two cases showing pT1a-EP/LPM and one showing pT1a-MM experienced lymph node recurrence. The 5 year cumulative incidence of local recurrence was 1.5% and 3.8% in the EP/LPM and MM groups, respectively (P = 0.455). The 5 year disease-specific survival (DSS) rate was 99.3% and 96.6% in the EP/LPM and MM groups, respectively (P = 0.118), whereas the 5 year overall survival rate was significantly higher in the EP/LPM group than in the MM group (92.6% versus 81.1%, respectively; P = 0.021).

CONCLUSIONS

As regards metastatic recurrence and DSS, ESCC patients with pT1a-MM without LVI showed favorable outcomes that were equivalent to those with pT1a-EP/LPM, even when they were not treated with additional therapy after ESD.

Synchronous Head and Neck Cancer and Superficial Esophageal Squamous Cell Neoplasm: Endoscopic Treatment or No Treatment for the Superficial Esophageal Neoplasm

There are no studies on treating synchronous head and neck cancer (HNC) and superficial esophageal squamous cell neoplasm (SESCN). We aimed to report the outcomes of endoscopic resection (ER) and no treatment (NT) of SESCN in patients with synchronous HNC and SESCN (SHNSESCN). This retrospective study included 47 patients with SHNSESCN. Treatment for SESCN was ER (n = 30) or NT (n = 17). The ER group had significantly lower Charlson comorbidity index scores and a higher proportion of Eastern Cooperative Oncology Group performance status (ECOG PS) scores ≤1. The location and stage of the two tumors did not differ significantly between the groups. The 1-year, 3-year, and 5-year OS rates of the ER group were significantly better than those in the NT group. Treatment-related morbidity and mortality were not significantly different between the two groups. In the subgroup analysis of synchronous advanced HNC and SESCN, ER for SESCN also had a higher OS rate. Multivariate analysis showed that ECOG PS score and HNC disease progression were the two independent indicators of OS. In conclusion, treatment of SESCN with ER is the recommended approach for patients with SHNSESCN, but further randomized controlled trials are needed to confirm this.

Blood biomarkers as predictors of pathological lymph node metastasis in clinical stage T1N0 esophageal squamous cell carcinoma

Accurate preoperative evaluation of lymph node (LN) metastasis is important for determining the treatment strategy for superficial esophageal cancer. Blood biomarkers, such as the neutrophil-lymphocyte, platelet-lymphocyte, and lymphocyte-monocyte ratios (NLR, PLR, and LMR, respectively), have clinical applications as predictors of LN metastasis for different cancers. Here, we investigated the use of these ratios as predictors of pathological LN metastasis and prognosis in patients with clinical stage T1N0M0 esophageal squamous cell carcinoma (ESCC). Patients (n = 185) with cT1N0M0 ESCC who underwent esophagectomy with R0 resection between April 2003 and August 2021 were enrolled. We investigated the ability of pretreatment NLR, PLR, and LMR to predict pathological LN metastasis. The optimal cutoff values of NLR, PLR, and LMR to predict pathological LN metastasis were 2.1, 122, and 4.8, respectively. Univariate and multivariate analyses revealed that the primary tumor length, depth of invasion, and NLR were significant predictors of LN metastasis. Furthermore, similar to the 5-year overall survival, the 5-year relapse-free survival was significantly better in the low NLR group than in the high NLR group. The NLR was the most useful predictor of pathological LN metastasis. Patients diagnosed with clinical stage I ESCC and with a high NLR require adequate LN dissection and may be good candidates for preoperative adjuvant therapy.

Impact of endoscopic surveillance on mortality of metachronous esophageal and head and neck cancer after esophageal endoscopic resection

BACKGROUND AND AIM

As more superficial esophageal cancer (EC) patients are being treated with endoscopic resection (ER), it is important to understand the outcomes, including survival data, of patients who develop metachronous EC and head and neck cancer (HNC). We aimed to evaluate the long-term surveillance and survival outcomes of metachronous EC and HNC after esophageal ER.

METHODS

This study included 627 patients who underwent ER of superficial esophageal squamous cell carcinoma from 2008 to 2016 and were generally followed by annual or biannual esophagogastroduodenoscopy up to 2019 at Osaka International Cancer Institute. Data on metachronous cancer development and causes of death were collected from an integrated database of hospital-based cancer registry and Vital Statistics of Japan.

RESULTS

During a median (range) follow-up period of 67.4 (3.8-142.7) months, 230 patients (36.7%) developed 500 metachronous ECs and 126 patients (20.1%) developed 239 metachronous HNCs, post-ER of index EC. The 3-year, 5-year, and 7-year cumulative incidences were 25.8%, 36.0%, and 43.6% for metachronous EC and 10.9%, 16.0%, and 26.9% for metachronous HNC, respectively. No patients died of metachronous EC, and only seven patients (1.1%) died of metachronous HNC. The 3-year, 5-year, and 7-year disease-specific survival rates were 99.8%, 99.6%, and 98.6%, respectively.

CONCLUSIONS

The incidences of metachronous EC and HNC increase with time over 5 years after esophageal ER; therefore, surveillance endoscopy should be continued over 5 years. Endoscopic surveillance is useful for survivors after esophageal ER given the high incidence and extremely low mortality of metachronous EC and HNC.

ME-NBI combined with endoscopic ultrasonography for diagnosing and staging the invasion depth of early esophageal cancer: a diagnostic meta-analysis

Background

Several methods can assist in detecting early esophageal cancer (EEC) and staging esophageal cancer (EC) invasion depth.

Objective

To evaluate the accuracy of magnifying endoscopy with narrow-band imaging (ME-NBI) plus endoscopic ultrasonography (EUS) for diagnosing EC.

Methods

We searched the PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases for relevant studies. The Quality Assessment of Diagnostic Accuracy Studies 2 (QADAS2) was used to assess the studies’ methodological quality. The sensitivity, specificity, positive likelihood (LR+), negative likelihood (LR−), and diagnostic odds ratio (DOR) were calculated, and the summary receiver operating characteristic (SROC) curves were drawn to evaluate the diagnostic performance.

Results

Seven studies were included. The meta-analysis suggested that the pooled sensitivity, specificity, LR+, LR−, and DOR of ME-NBI plus EUS for diagnosing EC were 0.947 (95% confidence interval [CI], 0.901–0.975), 0.894 (95% CI, 0.847–0.931), 7.989 (95% CI, 4.264–14.970), 0.066 (95% CI, 0.035–0.124), and 137.96 (95% CI, 60.369–315.27), respectively. Those values for staging the invasive depth were 0.791 (95% CI, 0.674–0.881), 0.943 (95% CI, 0.906–0.968), 13.087 (95% CI, 7.559–22.657), 0.226 (95% CI, 0.142–0.360), and 61.332 (95% CI, 27.343–137.57). The areas under the curves (AUCs) for diagnosis and staging were 0.97 and 0.95, respectively.

Conclusions

ME-NBI plus EUS might be an adequate diagnostic and staging modality for EC. Due to the study limitations, more large-scale, high-quality studies are needed to confirm the diagnostic accuracy of ME-NBI plus EUS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02809-6.

Salvage endoscopic resection for cT1N0M0 local recurrence after chemoradiotherapy for esophageal squamous cell carcinoma: endoscopic submucosal dissection versus endoscopic mucosal resection

OBJECTIVES

Salvage endoscopic resection is recommended when the local recurrence at primary site after chemoradiotherapy for esophageal squamous cell carcinoma is localized and superficial. This retrospective study aimed to comparatively analyse the short-term outcomes and local control of salvage endoscopic submucosal dissection versus salvage endoscopic mucosal resection for local recurrence after chemoradiotherapy or radiotherapy.

METHODS

A total of 96 patients who underwent initial salvage endoscopic resection for cT1N0M0 local recurrence after chemoradiotherapy or radiotherapy for esophageal squamous cell carcinoma between December 1998 and August 2019 patients were assigned to either the salvage endoscopic submucosal dissection (40 patients; 40 lesions) or salvage endoscopic mucosal resection (56 patients; 56 lesions) group. We evaluated the en bloc and R0 resection rates, severe adverse events and local failure rate after salvage endoscopic resection. Multivariate analysis was conducted to identify risk factors of local failure after salvage endoscopic resection.

RESULTS

The en bloc resection rate was significantly higher in the salvage endoscopic submucosal dissection group than in the salvage endoscopic mucosal resection group (95% versus 63%; P < 0.001). There were no differences in R0 resection rate between the two groups (73% versus 52%, P = 0.057). One patient (3%) in the salvage endoscopic submucosal dissection group had perforation. The 3-year cumulative local failure rate of salvage endoscopic mucosal resection was significantly higher than that of salvage endoscopic submucosal dissection (27% versus 5%, P = 0.032). In multivariate analysis, salvage endoscopic mucosal resection (hazard ratio: 2.7, P = 0.044) was the only independent risk factor of local failure after salvage endoscopic resection.

CONCLUSIONS

Salvage endoscopic submucosal dissection is the effective treatment for local recurrence based on the short-term outcomes and local efficacy.

Positive predictive value of the clinical diagnosis of T1a-epithelial/lamina propria esophageal cancer depends on lesion size

OBJECTIVES

Endoscopic resection (ER) is a minimally invasive treatment for esophageal squamous cell carcinoma (ESCC). However, stricture may develop after ER for widespread lesions. Application of ER is justified if these cancers are pathological T1a-epithelial/lamina propria (pEP/LPM) cancers that can be cured by ER. We conducted a study to clarify the association between pathological invasion depth and lesion size or circumference in clinical (c) EP/LPM cancers.

METHODS

From our database, we identified patients diagnosed with cEP/LPM ESCC via endoscopic examination who underwent endoscopic or surgical tumor resection. The accuracy of the cEP/LPM ESCC diagnosis was determined by histologically diagnosing cancer invasion depth as a reference standard.

RESULTS

Between January 2015 and December 2019, 1271 cancer patients were diagnosed with cEP/LPM ESCC, of which 1195 (94.0%) were correctly diagnosed with pEP/LPM cancer. The positive predictive value (PPV) classified according to lesion sizes of ≤25, 26-49, and ≥50 mm was 95.8% (981/1024 lesions), 89.7% (191/213 lesions), and 67.6% (23/34 lesions), respectively. PPV according to the circumferential extent of <3/4, ≥3/4, and <1, and whole was 94.6% (1164/1230 lesions), 75.0% (24/32 lesions), and 77.8% (7/9 lesions), respectively. In multivariate analysis, the PPV of cEP/LPM ESCC was significantly associated with lesion size (P < 0.001) and male sex.

CONCLUSIONS

Between January 2015 and December 2019, 1271 cancer patients were diagnosed with cEP/LPM ESCC, of which 1195 (94.0%) were correctly diagnosed with pEP/LPM cancer. The PPV of cEP/LPM ESCC was related to lesion size. Treatment should be determined considering the high risk of cancer invasion into the muscularis mucosa or deeper in cEP/LPM cancers with a lesion size of ≥50 mm.

Utility of an artificial intelligence system for classification of esophageal lesions when simulating its clinical use

Previous reports have shown favorable performance of artificial intelligence (AI) systems for diagnosing esophageal squamous cell carcinoma (ESCC) compared with endoscopists. However, these findings don’t reflect performance in clinical situations, as endoscopists classify lesions based on both magnified and non-magnified videos, while AI systems often use only a few magnified narrow band imaging (NBI) still images. We evaluated the performance of the AI system in simulated clinical situations. We used 25,048 images from 1433 superficial ESCC and 4746 images from 410 noncancerous esophagi to construct our AI system. For the validation dataset, we took NBI videos of suspected superficial ESCCs. The AI system diagnosis used one magnified still image taken from each video, while 19 endoscopists used whole videos. We used 147 videos and still images including 83 superficial ESCC and 64 non-ESCC lesions. The accuracy, sensitivity and specificity for the classification of ESCC were, respectively, 80.9% [95% CI 73.6–87.0], 85.5% [76.1–92.3], and 75.0% [62.6–85.0] for the AI system and 69.2% [66.4–72.1], 67.5% [61.4–73.6], and 71.5% [61.9–81.0] for the endoscopists. The AI system correctly classified all ESCCs invading the muscularis mucosa or submucosa and 96.8% of lesions ≥ 20 mm, whereas even the experts diagnosed some of them as non-ESCCs. Our AI system showed higher accuracy for classifying ESCC and non-ESCC than endoscopists. It may provide valuable diagnostic support to endoscopists.

Early Esophageal Cancer: What the Gastroenterologist Needs to Know

Endoscopic findings in early esophageal cancer are often subtle and require careful inspection and meticulous endoscopic examination. When dysplasia is suspected, we recommend performing 1 or 2 targeted biopsies of the abnormal area and review with a pathologist specialized in evaluating gastrointestinal diseases. In the case of adenocarcinoma, after resection of any visible cancer, residual Barrett's can be treated by ablation. Endoscopic resection can offer the opportunity for patients to avoid surgery. Further studies are needed to evaluate the optimal management of circumferential and near-circumferential lesions as well as tools and techniques to facilitate the performance of endoscopic submucosal dissection and endoscopic mucosal resection.

Artificial intelligence diagnostic system predicts multiple Lugol-voiding lesions in the esophagus and patients at high risk for esophageal squamous cell carcinoma

BACKGROUND

It is known that an esophagus with multiple Lugol-voiding lesions (LVLs) after iodine staining is high risk for esophageal cancer; however, it is preferable to identify high-risk cases without staining because iodine causes discomfort and prolongs examination times. This study assessed the capability of an artificial intelligence (AI) system to predict multiple LVLs from images that had not been stained with iodine as well as patients at high risk for esophageal cancer.

METHODS

We constructed the AI system by preparing a training set of 6634 images from white-light and narrow-band imaging in 595 patients before they underwent endoscopic examination with iodine staining. Diagnostic performance was evaluated on an independent validation dataset (667 images from 72 patients) and compared with that of 10 experienced endoscopists.

RESULTS

The sensitivity, specificity, and accuracy of the AI system to predict multiple LVLs were 84.4 %, 70.0 %, and 76.4 %, respectively, compared with 46.9 %, 77.5 %, and 63.9 %, respectively, for the endoscopists. The AI system had significantly higher sensitivity than 9/10 experienced endoscopists. We also identified six endoscopic findings that were significantly more frequent in patients with multiple LVLs; however, the AI system had greater sensitivity than these findings for the prediction of multiple LVLs. Moreover, patients with AI-predicted multiple LVLs had significantly more cancers in the esophagus and head and neck than patients without predicted multiple LVLs.

CONCLUSION

The AI system could predict multiple LVLs with high sensitivity from images without iodine staining. The system could enable endoscopists to apply iodine staining more judiciously.

Usefulness of an artificial intelligence system for the detection of esophageal squamous cell carcinoma evaluated with videos simulating overlooking situation

OBJECTIVES

Artificial intelligence (AI) systems have shown favorable performance in the detection of esophageal squamous cell carcinoma (ESCC). However, previous studies were limited by the quality of their validation methods. In this study, we evaluated the performance of an AI system with videos simulating situations in which ESCC has been overlooked.

METHODS

We used 17,336 images from 1376 superficial ESCCs and 1461 images from 196 noncancerous and normal esophagi to construct the AI system. To record validation videos, the endoscope was passed through the esophagus at a constant speed without focusing on the lesion to simulate situations in which ESCC has been missed. Validation videos were evaluated by the AI system and 21 endoscopists.

RESULTS

We prepared 100 video datasets, including 50 superficial ESCCs, 22 noncancerous lesions, and 28 normal esophagi. The AI system had sensitivity of 85.7% (54 of 63 ESCCs) and specificity of 40%. Initial evaluation by endoscopists conducted with plain video (without AI support) had average sensitivity of 75.0% (47.3 of 63 ESCC) and specificity of 91.4%. Subsequent evaluation by endoscopists was conducted with AI assistance, which improved their sensitivity to 77.7% (P = 0.00696) without changing their specificity (91.6%, P = 0.756).

CONCLUSIONS

Our AI system had high sensitivity for the detection of ESCC. As a support tool, the system has the potential to enhance detection of ESCC without reducing specificity. (UMIN000039645).

Metallothionein 2A Expression in Cancer-Associated Fibroblasts and Cancer Cells Promotes Esophageal Squamous Cell Carcinoma Progression

Esophageal cancer has the sixth highest mortality rate worldwide. Cancer-associated fibroblasts (CAFs) are involved in the progression of various cancers. Previously, we demonstrated an association between high expression of the CAF marker, fibroblast activation protein, and poor prognosis of esophageal squamous cell carcinoma (ESCC). We also established CAF-like cells by indirect co-culture of bone marrow-derived mesenchymal stem cells with ESCC cell lines and found metallothionein 2A (MT2A) to be highly expressed in them. Here, to explore the function of MT2A in CAFs, we silenced MT2A in the CAF-like cells and ESCC cell lines using small interfering RNA. MT2A knockdown in the CAF-like cells suppressed expression and secretion of insulin-like growth factor binding protein 2 (IGFBP2); recombinant IGFBP2 promoted migration and invasiveness of ESCC cells via NFκB, Akt, and Erk signaling pathways. Furthermore, MT2A knockdown in the ESCC cell lines inhibited their growth, migration, and invasiveness. Immunohistochemistry demonstrated that high MT2A expression in the cancer stroma and cancer nest of ESCC tissues correlated with poor prognosis of ESCC patients. Hence, we report that MT2A in CAFs and cancer cells contributes to ESCC progression. MT2A and IGFBP2 are potential novel therapeutic targets in ESCC.

Soft palate findings associated with a high risk of esophageal squamous cell carcinoma using an endoscopic system with enhanced depth-of-field imaging

Background and Aims

We previously reported that 3 endoscopic findings of melanosis, whitish epithelium, and vasodilation in the soft palate are associated with a high risk of esophageal squamous cell carcinoma (ESCC). Conventional endoscopic systems require observation under magnification to evaluate vasodilation. This case series aims to present the evaluation of vasodilation without magnification using an endoscopic system with enhanced depth-of-field (EDOF) imaging.

Methods

We observed the soft palate of 3 patients with early ESCC using an endoscopic system with EDOF (GIF-EZ1500 and EVIS X1 CV-1500, Olympus Co, Tokyo, Japan).

Results

The patient in case 1 had marked melanosis, whitish epithelium, and vasodilation (focal type) in the soft palate. The patient in case 2 had melanosis and vasodilation (diffuse type) in the soft palate. The vasodilation in cases 1 and 2 could be evaluated sufficiently without magnification. The patient in case 3 had melanosis and whitish epithelium in the soft palate. The color tone of melanosis became sharpened using texture and color enhancement imaging.

Conclusions

The endoscopic system with EDOF enabled us to evaluate all 3 soft palate findings associated with a high risk of ESCC, without magnification.

A clinically interpretable convolutional neural network for the real-time prediction of early squamous cell cancer of the esophagus: comparing diagnostic performance with a panel of expert European and Asian endoscopists

BACKGROUND AND AIMS

Intrapapillary capillary loops (IPCLs) are microvascular structures that correlate with the invasion depth of early squamous cell neoplasia and allow accurate prediction of histology. Artificial intelligence may improve human recognition of IPCL patterns and prediction of histology to allow prompt access to endoscopic therapy for early squamous cell neoplasia where appropriate.

METHODS

One hundred fifteen patients were recruited at 2 academic Taiwanese hospitals. Magnification endoscopy narrow-band imaging videos of squamous mucosa were labeled as dysplastic or normal according to their histology, and IPCL patterns were classified by consensus of 3 experienced clinicians. A convolutional neural network (CNN) was trained to classify IPCLs, using 67,742 high-quality magnification endoscopy narrow-band images by 5-fold cross validation. Performance measures were calculated to give an average F1 score, accuracy, sensitivity, and specificity. A panel of 5 Asian and 4 European experts predicted the histology of a random selection of 158 images using the Japanese Endoscopic Society IPCL classification; accuracy, sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

Expert European Union (EU) and Asian endoscopists attained F1 scores (a measure of binary classification accuracy) of 97.0% and 98%, respectively. Sensitivity and accuracy of the EU and Asian clinicians were 97%, 98% and 96.9%, 97.1%, respectively. The CNN average F1 score was 94%, sensitivity 93.7%, and accuracy 91.7%. Our CNN operates at video rate and generates class activation maps that can be used to visually validate CNN predictions.

CONCLUSIONS

We report a clinically interpretable CNN developed to predict histology based on IPCL patterns, in real time, using the largest reported dataset of images for this purpose. Our CNN achieved diagnostic performance comparable with an expert panel of endoscopists.

Validity of endoscopic resection for clinically diagnosed T1a-MM/T1b-SM1 N0 M0 esophageal squamous cell carcinoma

BACKGROUND

Previous guidelines have not described clear recommendations for performing endoscopic resection (ER) of T1a-muscularis mucosa (MM)/T1b-submucosal (SM1) cancers that have invaded ≤ 200 μm because these are considered to have a non-negligible risk of metastasis based on previous analyses of pathologically diagnosed (p)MM/SM1 cancers. Considering that the indication for ER is determined based on a clinical diagnosis, the applicability of ER should be investigated in clinical (c)MM/SM1 but not pMM/SM1 cancers. This study aimed to evaluate validity of ER for cMM/SM1 cancers.

METHODS

In total, 175 cMM/SM1 esophageal squamous cell carcinoma cases that were endoscopically or surgically resected between January 2008 and December 2018 were identified from a prospectively maintained database. We histologically evaluated resected specimens and divided them into low- (n = 92) and high-risk (n = 83) cancers for metastasis.

RESULTS

Univariate analysis showed that longer tumor length and larger circumferential extent were significantly correlated with high-risk cancer (P < 0.001). Multivariate analysis showed that tumor circumference was an independent predictor of high-risk cancer (P = 0.036). The proportion of low-risk cancers among cases with ≤ 3/4, > 3/4 and < 1, and whole circumferential extent were 59, 17, and 14%, respectively, and the post-ER stricture rates of these groups were 12, 33, and 100%, respectively.

CONCLUSION

ER is the first-line treatment for cMM/SM1 cancers with ≤ 3/4 circumferential extent considering that 59% of cMM/SM1 cancers were low-risk cancers for which ER is mostly curative. ER is not recommended for whole circumferential cMM/SM1 cancers given the low proportion of low-risk cancers and the high risk of stricture after ER.

Clinical outcomes of endoscopic resection of preoperatively diagnosed non-circumferential T1a-muscularis mucosae or T1b-submucosa 1 esophageal squamous cell carcinoma

In Japan, preoperatively diagnosed T1a-muscularis mucosae or T1b-submucosa 1 (MM/SM1) esophageal squamous cell carcinoma (ESCC) is a relative indication for endoscopic resection (ER). We evaluated long-term outcomes in patients after ER for non-circumferential ESCC with a preoperative diagnosis of MM/SM1 invasion. We retrospectively reviewed 66 patients with a preoperative diagnosis of non-circumferential MM/SM1 ESCC endoscopically resected between 2010 and 2015. Patients were divided into low- (adequate follow-up) and high-risk (requiring additional treatment) groups for lymph node metastasis according to risk factors (submucosal invasion, lymphovascular invasion, or droplet infiltration) and long-term outcomes were analyzed. Pathological invasion to T1a-lamina propria mucosa, MM/SM1, and T1b-SM2 was seen in 22, 38, and 6 lesions, respectively. Overall, 71.2% patients were classified into the "adequate follow-up" group. Of these, only one patient had a lymph node recurrence, which was successfully treated by additional therapy. The remaining 28.8% patients were classified into the "requiring additional treatment" group, where no recurrences were observed after additional treatments. After a median follow-up of 58.6 months, no deaths happened due to ESCC. The 3- and 5-year overall survival rates were 93.6% and 88.7%, respectively. ER is a valid initial treatment for non-circumferential ESCC with preoperatively diagnosed MM/SM1 invasion.

Long-term Outcomes and Factors Affecting the Survival of Patients with Mucosal Esophageal Squamous Cell Carcinoma

Background/Aims

Data regarding the prognosis of early esophageal cancer are lacking. This study investigated the long-term outcomes and factors affecting the survival of patients with mucosal esophageal squamous cell carcinoma (T1aESCC).

Methods

We analyzed the clinical and tumor-specific parameters of 263 patients who received surgical resection (SR; n=63) or endoscopic resection (ER; n=200) for T1aESCC. Underlying comorbidities were scored using the Charlson Comorbidity Index (CCI). Overall survival (OS) was the primary outcome, and multivariate regression analysis was performed to predict factors for OS.

Results

Of the study patients (age, 64.5±8.0 years), the CCI was 1.0±1.4 in the ER group and 0.6±0.9 in the SR group (p=0.107). The 5-year OS rate during follow-up (54.4±20.4 months) was 85.7% (ER group, 86.8%; SR group, 82.4%; p=0.631). The cumulative 5-year incidence of esophageal cancer recurrence was 10.5% in the ER group (vs 0% in the SR group). The overall mortality rate was 12.9% (12.0% in the ER group and 15.9% in the SR group; p=0.399). The most common cause of mortality was second primary cancers in the ER group (75%) and organ dysfunction or postoperative complications in the SR group (70%). According to multivariate analysis, only CCI was significantly associated with OS (p<0.001). The 5-year OS rate in patients with a CCI >2 and in those with a CCI ≤2 was 60.2% and 88.2%, respectively (p<0.001). The treatment method (ER vs SR) was not a significant affecting factor (p=0.238).

Conclusions

The long-term prognosis of patients with T1aESCC was significantly associated with underlying comorbidities.

Long-term outcomes of endoscopic versus surgical resection for MM-SM1 esophageal squamous cell carcinoma using propensity score analysis

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) confined to the muscularis mucosae (MM) or up to 200 µm of the submucosa (SM1) confers the risk for lymph node metastasis, and is defined as relative indication for endoscopic submucosal dissection (ESD) by the Japan Esophageal Society guidelines. Although additional surgical treatment after ESD is recommended, long-term outcomes of ESD compared with those of surgery have not been clarified. This study aimed to evaluate the long-term outcomes of ESD and surgery for cN0M0 relative indication lesions of ESCC.

METHODS

Between 2006 and 2016, patients with relative indication lesions of ESCC who underwent ESD or surgery at nine participating hospitals were examined retrospectively. Using propensity score matching, we evaluated survival curves for and hazard ratios associated with endoscopic submucosal dissection and surgery.

RESULTS

In total, 155 lesions in the ESD group and 106 lesions in the surgery group met the pathological criteria of relative indication for endoscopic resection. After matching, 50 matched pairs of patients who underwent ESD or surgery were selected. The 5-year overall survival rates were 84.5% [95% confidence interval (CI) 68-93] in the ESD group and 79% [95% CI 60-90] in the surgery group. The hazard ratio of mortality for ESD compared with that for surgery estimated by Cox regression analysis was 0.79 (95% CI 0.3-2.06, p = 0.63).

CONCLUSIONS

Compared with surgery, ESD does not compromise long-term outcomes. ESD alone or ESD with chemotherapy and/or radiotherapy may be an option for the treatment of MM and SM1 ESCC.

Artificial intelligence for cancer detection of the upper gastrointestinal tract

In recent years, artificial intelligence (AI) has been found to be useful to physicians in the field of image recognition due to three elements: deep learning (that is, CNN, convolutional neural network), a high-performance computer, and a large amount of digitized data. In the field of gastrointestinal endoscopy, Japanese endoscopists have produced the world's first achievements of CNN-based AI system for detecting gastric and esophageal cancers. This study reviews papers on CNN-based AI for gastrointestinal cancers, and discusses the future of this technology in clinical practice. Employing AI-based endoscopes would enable early cancer detection. The better diagnostic abilities of AI technology may be beneficial in early gastrointestinal cancers in which endoscopists have variable diagnostic abilities and accuracy. AI coupled with the expertise of endoscopists would increase the accuracy of endoscopic diagnosis.

Esophageal squamous dysplasia and cancer: Is artificial intelligence our best weapon?

Esophageal cancer is the eight most common cancer in the world and is associated with a poor prognosis. Significant efforts are necessary to improve the detection of early squamous cell cancer such that curative endoscopic therapy can be offered. Studies have shown an overall miss rate of esophageal cancer of up to 6.4%. Human factors including fatigue and lack of attention may be a contributory factor. Computer aided detection and characterisation of early squamous cell cancer can be a second reader which potentially offsets these factors. Recent studies developing artificial intelligence systems show real promise in the detection of early squamous cell cancer and predicting depth of invasion to aid in the management of patients in the same endoscopic session. This has the potential to revolutionise this area of endoscopy.

Preoperative Diagnosis and Indications for Endoscopic Resection of Superficial Esophageal Squamous Cell Carcinoma

Endoscopic resection (ER) is the mainstay of treatment for superficial esophageal squamous cell carcinoma (SESCC) instead of esophagectomy because of its minimal invasiveness and favorable clinical outcomes. Developments in endoscopic submucosal dissection have enabled en bloc resection of SESCCs regardless of size, thus reducing the risk of local recurrence. Although ER for SESCC is effective, metastasis may subsequently occur. Additionally, extensive esophageal ER confers a risk of postoperative esophageal stricture. Therefore, accurate assessment of the invasion depth and circumferential extent of SESCCs is important in determining the indications for ER. Diagnostic accuracies for SESCC invasion differ between epithelial (EP)/lamina propria (LPM), muscularis mucosa (MM)/submucosal (SM1), and SM2 cancers. ER is strongly indicated for clinically diagnosed (c)EP/LPM cancers because 90% of these are as pathologically diagnosed (p)EP/LPM, which has a very low risk of metastasis. Remarkably, the diagnostic accuracy for cMM/SM1 differs significantly with lateral spread of cancer. Eighty percent of cMM/SM1 cancers with ≤3/4 circumferential spread prove to be pEP/LPM or pMM/SM1, which have very low or low risk of metastasis. Thus, these are adequate candidates for ER. However, given the relatively low proportion of pEP/LPM or pMM/SM1 and high risk of subsequent stricture, ER is not recommended for whole circumferential cMM/SM1 cancers. For cMM/SM1 cancers that involve >3/4 but not the whole circumference, ER should be considered on a lesion-by-lesion basis because the risk of post-ER stricture is not very high, but the proportion of pEP/LPM or pMM/SM1 is relatively low. ER is contraindicated for cSM2 cancers because 75% of them are pSM2, which has high risk of metastasis.

Regenerative medicine for the upper gastrointestinal tract

The main surgical strategy for gastrointestinal tract malignancy is en bloc resection, which consists of not only resection of the involved organs but also simultaneous resection of the surrounding or adjacent mesenteries that contain lymph vessels and nodes. After resection of the diseased organs, the defect of the gastrointestinal conduit is replaced with organs located downstream, such as the stomach and jejunum. However, esophageal and gastric reconstruction using these natural substitutes is associated with a diminished quality of life due to the loss of the reserve function, damage to the antireflux barrier, and dumping syndrome. Thus, replacement of the deficit after resection with the patient's own regenerated tissue to compensate for the lost function and tissue using regenerative medicine will be an ideal treatment. Many researchers have been trying to construct artificial organs through tissue engineering techniques; however, none have yet succeeded in growing a whole organ because of the complicated functions these organs perform, such as the processing and absorption of nutrients. While exciting results have been reported with regard to tissue engineering techniques concerning the upper gastrointestinal tract, such as the esophagus and stomach, most of these achievements have been observed in animal models, and few successful approaches in the clinical setting have been reported for the replacement of mucosal defects. We review the recent progress in regenerative medicine in relation to the upper gastrointestinal tract, such as the esophagus and stomach. We also focus on the functional capacity of regenerated tissue and its role as a culture system to recapitulate the mechanisms underlying infectious disease. With the emergence of technology such as the fabrication of decellularized constructs, organoids and cell sheet medicine, collaboration between gastrointestinal surgery and regenerative medicine is expected to help establish novel therapeutic modalities in the future.

Real-time assessment of video images for esophageal squamous cell carcinoma invasion depth using artificial intelligence

BACKGROUND

Although optimal treatment of superficial esophageal squamous cell carcinoma (SCC) requires accurate evaluation of cancer invasion depth, the current process is rather subjective and may vary by observer. We, therefore, aimed to develop an AI system to calculate cancer invasion depth.

METHODS

We gathered and selected 23,977 images (6857 WLI and 17,120 NBI/BLI images) of pathologically proven superficial esophageal SCC from endoscopic videos and still images of superficial esophageal SCC taken in our facility, to use as a learning dataset. We annotated the images with information [such as magnified endoscopy (ME) or non-ME, pEP-LPM, pMM, pSM1, and pSM2-3 cancers] based on pathologic diagnosis of the resected specimens. We created a model using a convolutional neural network. Performance of the AI system was compared with that of invited experts who used the same validation video set, independent of the learning dataset.

RESULTS

Accuracy, sensitivity, and specificity with non-magnified endoscopy (ME) were 87%, 50%, and 99% for the AI system and 85%, 45%, 97% for the experts. Accuracy, sensitivity, and specificity with ME were 89%, 71%, and 95% for the AI system and 84%, 42%, 97% for the experts.

CONCLUSIONS

Most diagnostic parameters were higher when done by the AI system than by the experts. These results suggest that our AI system could potentially provide useful support during endoscopies.

Long-term outcome of endoscopic resection for intramucosal esophageal squamous cell cancer: a secondary analysis of the Japan Esophageal Cohort study

BACKGROUND

Prospectively collected long-term data of patients undergoing endoscopic resection for superficial esophageal squamous cell carcinoma (ESCC) are limited. The aim of this study was to determine the prospectively collected long-term outcomes of endoscopic resection for ESCC as a secondary analysis of the Japan Esophageal Cohort (JEC) study.

METHODS

Patients who underwent endoscopic resection of intramucosal ESCC at 16 institutions between September 2005 and May 2010 were enrolled in the JEC study. All patients underwent endoscopic examination with iodine staining at 3 and 6 months after resection, and every 6 months thereafter. We investigated clinical courses after endoscopic resection, survival rates, and cumulative incidence of metachronous ESCC.

RESULTS

330 patients (mean age 67.0 years) with 396 lesions (mean size 20.4 mm) were included in the analysis. Lesions were diagnosed as high-grade intraepithelial neoplasia in 17.4 % and as squamous cell carcinoma in 82.6 % (limited to epithelium in 28.4 %, to lamina propria in 55.4 %, and to muscularis mucosa in 16.2 %). En bloc resection was achieved in 291 (73.5 %). The median follow-up period was 49.4 months. Local recurrences occurred in 13 patients (3.9 %) and were treated by endoscopic procedures. Lymph node metastasis occurred in two patients (0.6 %) after endoscopic resection. The 5-year overall, disease-specific, and metastasis-free survival rates were 95.1 %, 99.1 %, and 94.6 %, respectively. The 5-year cumulative incidence rate of metachronous ESCC was 25.7 %.

CONCLUSIONS

Our study demonstrated that endoscopic resection is an effective treatment for intramucosal ESCC, with favorable long-term outcomes.

Management following endoscopic resection in elderly patients with early-stage upper gastrointestinal neoplasia

With the ongoing increase in the aging population in Japan, the number of elderly patients among the total population with upper gastrointestinal (GI) neoplasia has also been increasing. As elderly patients present unique age-related variations in their physical condition, the therapeutic approach for upper GI neoplasia should be differentiated between elderly and nonelderly patients. According to the existing guidelines, additional treatment is the standard therapy in patients who undergo endoscopic resection (ER) with a possible risk of lymph node metastasis (LNM) for upper GI neoplasia. However, due to the relatively low rate of LNM, applying additional treatment in all elderly patients may be excessive. Although additional treatment has the advantage of reducing cancer-specific mortality, its disadvantages include deteriorated quality of life, complications, and mortality in surgery. In patients with early gastric cancer, we propose treatment decisions be made using a risk-scoring system for LNM and upon considering the physical condition of the patient after ER with curability C-2. In those with superficial esophageal squamous cell carcinoma with a possible risk of LNM after ER, selective chemoradiotherapy may be a less-invasive treatment option, although the present standard treatment is esophagectomy. When considering the treatment decision, achieving a "cure" of the tumor has been regarded as critical. However, as the main cause of mortality in elderly patients with ER for upper GI neoplasia is noncancer-related death, both achieving a "cure" and also a good level of "care" is important in the management of elderly patients.

Evaluation of metastatic lymph nodes in cN0 thoracic esophageal cancer patients with inconsistent pathological lymph node diagnosis

BACKGROUND

Preoperative clinical diagnosis of lymph node (LN) metastasis and subsequent pathological diagnosis are often not in agreement. Detection of false-negative LNs is essential in selecting an optimal treatment strategy, and most importantly, the presence of false-negative LN is itself a significant prognostic indicator. Therefore, at present, there is an urgent need to establish more accurate and individualized evaluation methods for LN metastasis.

METHODS

Of 213 cN0 patients who underwent curative esophagectomy without preoperative neoadjuvant treatment, 60 (28%) had LN metastasis diagnosed pathologically. There were 129 false-negative LNs, of which 85 were detectable by preoperative computed tomography (CT). We retrospectively investigated the distribution, frequency, and characteristics of pathologically positive nodes in patients with clinically N0 esophageal cancer.

RESULTS

The paracardial region was the most frequent region of false-negative LNs, accounting for 26% (22 LNs) of the total incidence. False-negative LNs distributed widely from the neck to the abdomen in patients with a primary tumor in the middle thoracic esophagus. In patients with a primary tumor in the lower thoracic esophagus, four false-negative LNs were detected in the superior mediastinum. When the short-axis diameter, shape, and attenuation patterns of the LNs were used as criteria for metastasis diagnosis, they were insufficient for an accurate diagnosis. However, false-negative LNs in the most frequently occurring sites are characterized by smaller short-axis, suggesting that accurate diagnosis cannot be made unless the diagnostic criteria for the short-axis are reduced in addition to shape and attenuation.

CONCLUSIONS

Although restrictive to the most frequent regions of false-negative LNs occur, reducing size criterion and consideration of their shape and attenuation may contribute to improved diagnosis.

Endoscopic detection and differentiation of esophageal lesions using a deep neural network

BACKGROUND AND AIMS

Diagnosing esophageal squamous cell carcinoma (SCC) depends on individual physician expertise and may be subject to interobserver variability. Therefore, we developed a computerized image-analysis system to detect and differentiate esophageal SCC.

METHODS

A total of 9591 nonmagnified endoscopy (non-ME) and 7844 ME images of pathologically confirmed superficial esophageal SCCs and 1692 non-ME and 3435 ME images from noncancerous lesions or normal esophagus were used as training image data. Validation was performed using 255 non-ME white-light images, 268 non-ME narrow-band images/blue-laser images, and 204 ME narrow-band images/blue-laser images from 135 patients. The same validation test data were diagnosed by 15 board-certified specialists (experienced endoscopists).

RESULTS

Regarding diagnosis by non-ME with narrow-band imaging/blue-laser imaging, the sensitivity, specificity, and accuracy were 100%, 63%, and 77%, respectively, for the artificial intelligence (AI) system and 92%, 69%, and 78%, respectively, for the experienced endoscopists. Regarding diagnosis by non-ME with white-light imaging, the sensitivity, specificity, and accuracy were 90%, 76%, and 81%, respectively, for the AI system and 87%, 67%, and 75%, respectively, for the experienced endoscopists. Regarding diagnosis by ME, the sensitivity, specificity, and accuracy were 98%, 56%, and 77%, respectively, for the AI system and 83%, 70%, and 76%, respectively, for the experienced endoscopists. There was no significant difference in the diagnostic performance between the AI system and the experienced endoscopists.

CONCLUSIONS

Our AI system showed high sensitivity for detecting SCC by non-ME and high accuracy for differentiating SCC from noncancerous lesions by ME.

Prediction of lymph node metastasis by PET/CT metabolic parameters in patients with esophageal squamous cell carcinoma

OBJECTIVE

The aim of this study was to investigate the capability of F-FDG PET/computed tomography (CT)-related metabolic parameters to predict lymph node metastasis (LNM) and occult lymph node metastasis (OLNM) in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Totally 84 patients undergoing curative esophagectomy with lymph node dissection were enrolled in this study. Metabolic tumor volume (MTV) was measured using threshold-based methods with a threshold of 40% maximum standardized uptake value (SUVmax). The derivative of the volume (V)-threshold (T) function (volume difference/threshold difference) was defined as the heterogeneity factor (HF). In addition, SUVmax, SUVmean, total lesion glycolysis (TLG), maximum tumor-to-blood SUV ratio (SURmax), SURmean and several clinicopathologic parameters were analyzed to identify risk factors of LNM and OLNM.

RESULTS

SUVmax, SUVmean, MTV, TLG, SURmax, SURmean and HF were significantly different between LNM (+) and LNM (-). The optimal cut-off values of those parameters were 12.5, 8.34, 15.01, 117.185, 7.885, 4.855 and 0.300, respectively. Logistic regression analysis showed that MTV (OR = 1.127, P = 0.04) and SURmax (OR = 1.446, P = 0.004) were independent predictors of LNM, with sensitivity and specificity were 51.2%, 83.7% vs. 53.7%, 79.1%. In univariate and multivariate analysis, MTV was the sole parameter associated with OLMN (P = 0.024).

CONCLUSION

MTV and SURmax were statistically significant predictors of LNM in patients with ESCC, while MTV was a predictor of OLNM. High SURmax and MTV may indicate that the treatment planning should be tailored, which may improve patient prognosis.

Impact of the Charlson Comorbidity Index on the treatment strategy and survival in elderly patients after non-curative endoscopic submucosal dissection for esophageal squamous cell carcinoma: a multicenter retrospective study

BACKGROUND

In elderly patients with superficial esophageal squamous cell carcinoma (ESCC), the optimal treatment strategy after non-curative endoscopic submucosal dissection (ESD) remains unclear. We aimed to evaluate the validity of additional treatments after non-curative ESD and post-ESD survival predictors in elderly patients with ESCC.

METHODS

Elderly patients (age > 75 years) treated with ESD for ESCC between January 2010 and July 2014 at six tertiary referral hospitals in Japan were retrospectively investigated and stratified according to lymph node metastasis risk, based on histological findings (high-risk factors: positive lymphovascular invasion, submucosal invasion, and positive/indeterminate vertical margin) and post-ESD treatment strategy: group A (287 patients; low risk), group B (41 patients; high risk, without additional treatment), and group C (32 patients; high risk, with additional treatment). We evaluated 3- and 5-year overall survival and disease-specific survival, and prognostic factors for post-ESD survival.

RESULTS

At a median follow-up of 38, 40, and 49 months, respectively, there was 1 esophageal cancer-related death in group A, 1 in group B, and none in group C, whereas 22, 9, and 3 patients in groups A, B, and C died of other diseases. The groups differed significantly in overall survival (92.4%; 87.6%; 93.4%, p = 0.022), although not in disease-specific survival (99.4%; 96.3%; 100%, p = 0.217). On multivariate analysis, Charlson Comorbidity Index (CCI) ≥ 2 was the only independent risk factor for post-ESD death (hazard ratio 7.92; 95% confidence interval 3.42-18.3; p < 0.001).

CONCLUSIONS

A follow-up strategy without additional treatment after ESD for ESCC may be acceptable in high-risk elderly patients, especially for CCI ≥ 2.

Classification for invasion depth of esophageal squamous cell carcinoma using a deep neural network compared with experienced endoscopists

BACKGROUND AND AIMS

Cancer invasion depth is a critical factor affecting the choice of treatment in patients with superficial squamous cell carcinoma (SCC). However, the diagnosis of invasion depth is currently subjective and liable to interobserver variability.

METHODS

We developed a deep learning-based artificial intelligence (AI) system based on Single Shot MultiBox Detector architecture for the assessment of superficial esophageal SCC. We obtained endoscopic images from patients with superficial esophageal SCC at our facility between December 2005 and December 2016.

RESULTS

After excluding poor-quality images, 8660 non-magnified endoscopic (non-ME) and 5678 ME images from 804 superficial esophageal SCCs with pathologic proof of cancer invasion depth were used as the training dataset, and 405 non-ME images and 509 ME images from 155 patients were selected for the validation set. Our system showed a sensitivity of 90.1%, specificity of 95.8%, positive predictive value of 99.2%, negative predictive value of 63.9%, and an accuracy of 91.0% for differentiating pathologic mucosal and submucosal microinvasive (SM1) cancers from submucosal deep invasive (SM2/3) cancers. Cancer invasion depth was diagnosed by 16 experienced endoscopists using the same validation set, with an overall sensitivity of 89.8%, specificity of 88.3%, positive predictive value of 97.9%, negative predictive value of 65.5%, and an accuracy of 89.6%.

CONCLUSIONS

This newly developed AI system showed favorable performance for diagnosing invasion depth in patients with superficial esophageal SCC, with comparable performance to experienced endoscopists.

Retrospective Assessment of the Diagnostic Accuracy of the Depth of Invasion by Narrow Band Imaging Magnifying Endoscopy in Patients with Superficial Esophageal Squamous Cell Carcinoma

PURPOSE

Treatment strategies for superficial esophageal squamous cell carcinoma (S-ESCC) are determined mainly on the basis of the depth of invasion. We retrospectively studied the accuracy of the depth of tumor invasion, comprehensively assessed using the Japan Esophageal Society (JES) classification.

METHODS

The study group comprised 256 patients who underwent narrow band imaging (NBI) magnifying endoscopy, and endoscopic submucosal dissection for S-ESCC. The depth of invasion of S-ESCC was classified into three groups: EP/LPM, MM/SM1, and SM2. The following variables were studied retrospectively: (1) the diagnostic accuracy of non-magnifying white-light endoscopy, (2) the diagnostic accuracy of type B vessels, (3) the diagnostic accuracy of avascular area (AVA), (4) the diagnostic accuracy of the JES classification, and (5) the diagnostic accuracy of comprehensive diagnosis. The depth of invasion was assessed by white-light non-magnifying endoscopy, followed by NBI magnifying endoscopy.

RESULTS

The positive predictive value (PPV) of white-light non-magnifying endoscopy was 86% for EP/LPM, 53% MM/SM1, and 74% for SM2. The PPV of the diagnosis of type B vessels was 93% for EP/LPM, 62% for MM/SM1, and 74% for SM2. The PPV of the AVA diagnosis was 73% for EP/LPM, 89% for MM/SM1, and 100% for SM2. The PPV of diagnosis according to the JES classification was 93% for EP/LPM, 65% for MM/SM1, and 77% for SM2. The PPV of the comprehensive diagnosis was 94% for EP/LPM, 63%, for MM/SM1, and 75% for SM2.

CONCLUSIONS

The additional use of NBI magnifying endoscopy can enhance the diagnostic accuracy of the depth of invasion in patients with S-ESCC.

Histopathologic discrepancies between endoscopic forceps biopsy and endoscopic resection specimens in superficial esophageal squamous neoplasms

BACKGROUND AND AIM

Endoscopic forceps biopsy results that reflect the final pathologic results of an entire lesion are essential for making accurate diagnoses and appropriate therapeutic decisions for patients with superficial esophageal squamous neoplasms (SESNs). This study investigated the histopathologic discrepancies between endoscopic forceps biopsy and endoscopic resection specimens to elucidate the factors contributing to such discrepancies.

METHODS

This retrospective observational study involved 77 patients (84 lesions) who underwent endoscopic resections for SESNs, between January 2005 and August 2017, at the Pusan National University Hospital. The SESNs were classified as low-grade intraepithelial neoplasms (LGINs), high-grade intraepithelial neoplasms (HGINs), or squamous cell carcinomas (SCCs). Following slide reviews, the histopathologic concordance between endoscopic forceps biopsy and endoscopic resection specimens was assessed, in each case.

RESULTS

The histopathologic discrepancy rate between the endoscopic forceps biopsy and endoscopic resection specimens was 34.5% (29/84 lesions). Among the 29 diagnostically discordant lesions, upgrades and downgrades of the histopathologic diagnoses occurred for 27 and 2 lesions, respectively. The predominant discrepancies results in lesion upgrades from HGIN to SCC (n = 21) and from LGIN to SCC (n = 5). The two downgraded cases included one from SCC to HGIN and one from HGIN to LGIN. Multivariate analyses identified two factors that were significantly associated with the histopathologic discrepancies: upper esophageal location (odds ratio, 7.743; 95% confidence interval, 1.031-58.174; P = 0.047) and tumor area per biopsy ≥ 158.6 mm² /biopsy (odds ratio, 5.933; 95% confidence interval, 1.051-44.483; P = 0.044).

CONCLUSION

Histopathologic discrepancies were observed between endoscopic forceps biopsy and endoscopic resection specimens in patients with SESNs. Tumor location and tumor area/biopsy were both significantly associated with the discrepancies.

Artificial intelligence for the real-time classification of intrapapillary capillary loop patterns in the endoscopic diagnosis of early oesophageal squamous cell carcinoma: A proof-of-concept study

Background

Intrapapillary capillary loops (IPCLs) represent an endoscopically visible feature of early squamous cell neoplasia (ESCN) which correlate with invasion depth - an important factor in the success of curative endoscopic therapy. IPCLs visualised on magnification endoscopy with Narrow Band Imaging (ME-NBI) can be used to train convolutional neural networks (CNNs) to detect the presence and classify staging of ESCN lesions.

Methods

A total of 7046 sequential high-definition ME-NBI images from 17 patients (10 ESCN, 7 normal) were used to train a CNN. IPCL patterns were classified by three expert endoscopists according to the Japanese Endoscopic Society classification. Normal IPCLs were defined as type A, abnormal as B1-3. Matched histology was obtained for all imaged areas.

Results

This CNN differentiates abnormal from normal IPCL patterns with 93.7% accuracy (86.2% to 98.3%) and sensitivity and specificity for classifying abnormal IPCL patterns of 89.3% (78.1% to 100%) and 98% (92% to 99.7%), respectively. Our CNN operates in real time with diagnostic prediction times between 26.17 ms and 37.48 ms.

Conclusion

Our novel and proof-of-concept application of computer-aided endoscopic diagnosis shows that a CNN can accurately classify IPCL patterns as normal or abnormal. This system could be used as an in vivo, real-time clinical decision support tool for endoscopists assessing and directing local therapy of ESCN.

Inadequate steroid injection after esophageal ESD might cause mural necrosis

Background and study aims  Locoregional triamcinolone acetonide (TAC) injection is increasingly used for prevention of stricture after extensive endoscopic submucosal dissection (ESD) for superficial esophageal neoplasia. However, the safety of intramural TAC injection has not been elucidated. The aim of this study was to assess the clinical courses and histopathological changes after TAC injection into the muscle layer in a porcine model. Methods  Three pigs were subjected to ESD under general anesthesia. Two artificial 30-mm lesions were created at the oral and anal ends of the esophagus in each pig. TAC was injected into the muscle layer of the artificial oral ulcers (TAC group) and saline was injected into the muscle layer of the artificial anal ulcers (control group). Endoscopic, macroscopic, and histopathological evaluations were performed. Results  The artificial ulcers remained open at sacrifice on day 28 post-ESD in the three ulcers injected with TAC. Esophageal wall perforation and abscess spreading to the mediastinum were observed in two of the three ulcers in the TAC group. The abscesses involved the lungs, bronchi, and aortic adventitia. Severe inflammatory cell infiltration in the muscularis propria layer and significant muscularis propria degradation were observed in all three ulcers in the TAC group. Conclusions  This study suggests that TAC may cause deep mural damage when it is injected into the muscularis propria. Care should be taken not to inject TAC into the muscle layer when it is used to prevent post-ESD stricture formation.

Role of endoscopic therapy in early esophageal cancer

Esophageal carcinoma is a highly lethal cancer associated with high morbidity and mortality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two distinct histological types. There has been significant progress in endoscopic diagnosis and treatment of early stages of cancer using resection and ablation techniques, as shown in several trials in the recent past. Earlier detection of esophageal cancer and advances in treatment modalities have lead to improvement in the 5-year survival from 5% to about 20% in the past decade. Endoscopic eradication therapy is the preferred modality of treatment in cancer limited to mucosal layer of the esophagus as there is very low risk of lymph node metastasis, leading to high cure rates, low risk of recurrence and with few adverse effects. The most common adverse events seen are strictures, bleeding and rarely perforation which can be endoscopically managed. In patients with recurrent advanced disease or invasive tumor, esophagectomy with lymph node dissection remains the mainstay of treatment. There is debate on post-endoscopic surveillance with some studies suggesting closer follow up with upper endoscopy every 6 mo for the first 1-2 years and then annually for the 3 years while others recommending the appropriate action only if symptoms or other abnormalities develop. Overall, the field of endoscopic therapy is still evolving and focus should be placed on careful patient selection using a multidisciplinary approach.

Curative Criteria After Endoscopic Resection for Superficial Esophageal Squamous Cell Carcinomas

BACKGROUND

According to the Japanese Esophageal Society (JES) guidelines, risk factors for lymph node (LN) metastasis in the muscularis mucosa (MM)/submucosa to a depth of up to 200 μm (SM1) in cases of esophageal squamous cell carcinomas (ESCCs) include the presence of lymphatic invasion (ly), venous invasion (v), infiltration pattern (INF)c, and SM1. The long-term prognoses of these patients are unclear, and there are very few reports on the validation of the curative criteria for MM/SM1 ESCCs.

AIMS

To examine the long-term prognoses of these patients and the risk factors for LN metastasis of MM/SM1 ESCCs after endoscopic resection (ER).

METHODS

This study included patients with MM/SM1 ESCCs who underwent ER at Hiroshima University Hospital from December 1990 to November 2016. We evaluated the clinicopathological characteristics of 98 patients and overall survival, disease-specific survival, recurrence-free survival, and recurrence rates in the e-curative and non-e-curative groups.

RESULTS

The mean observation period was 75 months. There was no significant difference in disease-specific survival rate between the e-curative and non-e-curative groups (100 vs. 98%). There was no significant difference in disease-specific survival rates between the groups (100 vs. 98%). In contrast, the LN recurrence-free survival rate in patients with INFa, ly(-), and v(-) was significantly higher than that in patients with INFb/c, ly(+), or v(+) (100 and 87%, P < 0.05).

CONCLUSION

Contrary to the JES guidelines, our findings suggest that new criteria (MM/SM1, INFa, negative vertical margin (VM0), ly[-], and v[-]) may be associated with curative ER without additional treatment.

Long-Term Survival and Tumor Recurrence in Patients with Superficial Esophageal Cancer after Complete Non-Curative Endoscopic Resection: A Single-Center Case Series

Background/Aims

To report the long-term survival and tumor recurrence outcomes in patients with superficial esophageal cancer (SEC) after complete non-curative endoscopic resection (ER).

Methods

We retrieved ER data for 24 patients with non-curatively resected SEC. Non-curative resection was defined as the presence of submucosal and/or lymphovascular invasion on ER pathology. Relevant clinical and tumor-specific parameters were reviewed.

Results

The mean age of the 24 study patients was 66.3±8.3 years. Ten patients were closely followed up without treatment, while 14 received additional treatment. During a mean follow-up of 59.0±33.2 months, the 3- and 5-year survival rates of all cases were 90.7% and 77.6%, respectively. The 5-year overall survival rates were 72.9% in the close observation group and 82.1% in the additional treatment group (p=0.958). The 5-year cumulative incidences of all cases of recurrence (25.0% vs. 43.3%, p=0.388), primary EC recurrence (10.0% vs. 16.4%, p=0.558), and metachronous EC recurrence (16.7% vs. 26.7%, p=0.667) were similar between the two groups.

Conclusions

Patients with non-curatively resected SEC showed good long-term survival outcomes. Given the similar oncologic outcomes, close observation may be an option with appropriate caution taken for patients who are medically unfit to receive additional therapy.

Salvage endoscopic resection (ER) after chemoradiotherapy for esophageal squamous cell carcinoma: What are the risk factors for recurrence after salvage ER?

BACKGROUND AND AIM

Salvage endoscopic resection (ER) is among the curative treatments for superficial local failure after chemoradiotherapy (CRT) for esophageal squamous cell carcinoma (ESCC). The present study aimed to clarify risk factors for recurrence after salvage ER.

METHODS

This study enrolled consecutive ESCC patients treated with salvage ER for local failure after CRT between 1998 and 2013. Recurrences after salvage ER included locoregional recurrences and distant metastases. Multivariate analysis was carried out on clinicopathological parameters to identify risk factors for post-salvage ER recurrence.

RESULTS

Of the 72 patients enrolled in this study, 37/8/23/4 patients had been staged before CRT as cT1/T2/T3/T4 and 44/28 patients as cN0/N1, respectively, and local failures detected before salvage ER were residual lesions after CRT in 19 and local recurrences in 53 patients. Resected specimens were classified as pT1a (M) in 45 and pT1b (SM) in 27 patients. During the median 45-month follow up (range, 3-175 months) after salvage ER, 27 (38%) patients developed recurrence with a 3-year recurrence-free survival rate of 48.9% (95% confidence interval [CI], 36.5-60.3). Multivariate analysis showed that residual lesions after CRT (HR, 2.55; 95% CI, 1.32-4.94) and lesions with a submucosal tumor (SMT)-like appearance before salvage ER (HR, 2.08; 95% CI, 1.04-4.18) were significantly associated with post-salvage ER recurrence.

CONCLUSIONS

Clinical findings (e.g. residual tumors found immediately after CRT and macroscopic SMT-like appearance before salvage ER) were shown to be significant risk factors for post-salvage ER recurrence.

Regenerative medicine for the esophagus

Advances in tissue engineering techniques have made it possible to use human cells as biological material. This has enabled pharmacological studies to be conducted to investigate drug effects and toxicity, to clarify the mechanisms underlying diseases, and to elucidate how they compensate for impaired organ function. Many researchers have tried to construct artificial organs using these techniques, but none has succeeded in growing a whole organ. Unlike other digestive organs with complicated functions, such as the processing and absorption of nutrients, the esophagus has the relatively simple function of transporting content, which can be replicated easily by a substitute. In regenerative medicine, various combinations of materials have been applied, including scaffolding, cell sources, and bioreactors. Exciting results of tissue engineering techniques for the esophagus have been reported. In animal models, replacing full-thickness and full-circumferential defects remains challenging because of stenosis and leakage after implantation. Although many reports have manipulated various scaffolds, most have emphasized the importance of both epithelial and mesenchymal cells for the prevention of stenosis. However, the results of repair of partial full-thickness defects and mucosal defects have been promising. Two successful approaches for the replacement of mucosal defects in a clinical setting have been reported, although in contrast to the many animal models, there are few pilot studies in humans. We review the recent results and evaluate the future of regenerative medicine for the esophagus.

Fibroblast growth factor-2-mediated FGFR/Erk signaling supports maintenance of cancer stem-like cells in esophageal squamous cell carcinoma

In esophageal squamous cell carcinoma (ESCC), a subset of cells defined by high expression of CD44 and low expression of CD24 has been reported to possess characteristics of cancer stem-like cells (CSCs). Novel therapies directly targeting CSCs have the potential to improve prognosis of ESCC patients. Although fibroblast growth factor-2 (FGF-2) expression correlates with recurrence and poor survival in ESCC patients, the role of FGF-2 in regulation of ESCC CSCs has yet to be elucidated. We report that FGF-2 is significantly upregulated in CSCs and significantly increases CSC content in ESCC cell lines by inducing epithelial-mesenchymal transition (EMT). Conversely, the FGFR inhibitor, AZD4547, sharply diminishes CSCs via induction of mesenchymal-epithelial transition. Further experiments revealed that MAPK/Erk kinase (Mek)/extracellular signal-regulated kinases (Erk) pathway is crucial for FGF-2-mediated CSC regulation. Pharmacological inhibition of FGF receptor (FGFR)-mediated signaling via AZD4547 did not affect CSCs in Ras mutated cells, implying that Mek/Erk pathway, downstream of FGFR signaling, might be an important regulator of CSCs. Indeed, the Mek inhibitor, trametinib, efficiently suppressed ESCC CSCs even in the context of Ras mutation. Consistent with these findings in vitro, xenotransplantation studies demonstrated that inhibition of FGF-2-mediated FGFR/Erk signaling significantly delayed tumor growth. Taken together, these findings indicate that FGF-2 is an essential factor regulating CSCs via Mek/Erk signaling in ESCC. Additionally, inhibition of FGFR and/or Mek signaling represents a potential novel therapeutic option for targeting CSCs in ESCC.

Treatment outcomes of extended-field radiation therapy for thoracic superficial esophageal cancer

Purpose

To evaluate the efficacy and safety of extended-field radiation therapy for patients with thoracic superficial esophageal cancer (SEC).

Materials and Methods

From May 2007 to October 2016, a total of 24 patients with thoracic SEC (T1a and T1b) who underwent definitive radiotherapy and were analyzed retrospectively. The median total radiotherapy dose was 64 Gy (range, 54 to 66 Gy) in conventional fractionation. All 24 patients received radiotherapy to whole thoracic esophagus and 23 patients received elective nodal irradiation. The supraclavicular lymph nodes, the celiac lymph nodes, and both of those nodal areas were included in 11, 3, and 9 patients, respectively.

Results

The median follow-up duration was 28.7 months (range 7.9 to 108.0 months). The 3-year overall survival, local control, and progression-free survival rates were 95.2%, 89.7%, and 78.7%, respectively. There were 5 patients (20.8%) with progression of disease, 2 local failures (8.3%) and 3 (12.5%) regional failures. Three patients also experienced distant metastasis and had died of disease progression. There were no treatment-related toxicities of grade 3 or higher.

Conclusion

Definitive extended-field radiotherapy for thoracic SEC showed durable disease control rates in medically inoperable and endoscopically unfit patients. Even extended-field radiotherapy with elective nodal irradiation was safe without grade 3 or 4 toxicities.

Endoscopic diagnosis and management of early squamous cell carcinoma of esophagus

In recent years, diagnosis of early squamous cell carcinoma (SCC) of the esophagus has been increasingly emphasized. Utilization of image enhanced technology such as narrow band imaging (NBI) and magnification endoscopy allowed detailed examination of the esophageal mucosa. Different patterns of intrapapillary capillary loops (IPCL) have been proven to accurately diagnose and predict the depth of invasion of the tumors. In addition, the application of endoscopic submucosal dissection (ESD) has enabled safe en bloc resection of esophageal lesions. Promising results of ESD have been published and ESD is now the standard of therapy in early SCC of esophagus.

The five-year survival rate after endoscopic submucosal dissection for superficial esophageal squamous cell neoplasia

BACKGROUND

Endoscopic submucosal dissection (ESD) is a widely accepted procedure for superficial esophageal squamous cell neoplasia (ESCN) because of a high complete resection rate. However, there were a few reports about the long-term outcomes of these patients due to short follow-up periods.

AIMS

We aimed to evaluate the 5-year survival after ESD for superficial ESCN.

METHODS

This was a retrospective cohort study performed at a single institution. Between 2006 and 2009, 94 patients with superficial ESCN underwent ESD. Eighty-three patients (93.3%) who had completed an extended period of observation of at least 5 years were enrolled. The main outcomes were the 5-year survival rates. The secondary outcomes were the cumulative incidence rate of metachronous ESCN, and the clinical outcomes.

RESULTS

The 5-year relative overall survival rate was 99.0%, whereas the cause specific survival rate was 100% during 72.9 months of median follow up period. Subgroup analysis showed that the 5year survival of patients with EP/LPM and MM/SM1 (submucosal invasion ≤200μm) were 100% and 89.0%, respectively. The cumulative incidence rate of metachronous ESCN at 5 years was 16.8%.

CONCLUSION

ESD for superficial ESCN is a curative treatment with a favorable 5-year survival rate.