Development of Advanced Imaging and Molecular Imaging for Barrett's Neoplasia

Barrett esophagus (BE) is a precursor to a life-threatening esophageal adenocarcinoma (EAC). Surveillance endoscopy with random biopsies is recommended for early intervention against EAC, but its adherence in the clinical setting is poor. Dysplastic lesions with flat architecture and patchy distribution in BE are hardly detected by high-resolution endoscopy, and the surveillance protocol entails issues of time and labor and suboptimal interobserver agreement for diagnosing dysplasia. Therefore, the development of advanced imaging technologies is necessary for Barrett's surveillance. Recently, non-endoscopic or endoscopic technologies, such as cytosponge, endocytoscopy, confocal laser endomicroscopy, autofluorescence imaging, and optical coherence tomography/volumetric laser endomicroscopy, were developed, but most of them are not clinically available due to the limited view field, expense of the equipment, and significant time for the learning curve. Another strategy is focused on the development of molecular biomarkers, which are also not ready to use. However, a combination of advanced imaging techniques together with specific biomarkers is expected to identify morphological abnormalities and biological disorders at an early stage in the surveillance. Here, we review recent developments in advanced imaging and molecular imaging for Barrett's neoplasia. Further developments in multiple biomarker panels specific for Barrett's HGD/EAC include wide-field imaging systems for targeting 'red flags', a high-resolution imaging system for optical biopsy, and a computer-aided diagnosis system with artificial intelligence, all of which enable a real-time and accurate diagnosis of dysplastic BE in Barrett's surveillance and provide information for precision medicine.

Visceral obesity is associated with an increased risk of developing esophago-gastric junctional adenocarcinoma in Japan: a population-based case-control study in Akita Prefecture

BACKGROUND

While an association between esophago-gastric junctional adenocarcinomas (EGJACs) and obesity, especially visceral obesity, has been suggested in Western countries, the association remains unclear in Asia, including Japan. In this population-based case-control study, we investigated the association between EGJACs and obesity.

METHODS

To perform near-population-based data collection for all early-stage EGJACs occurring in Akita Prefecture from 2014 to 2019, clinical data, including endoscopic and computed tomography (CT) findings, were collected from 11 cancer treatment base hospitals in the area. Age- and gender-matched controls were extracted at a case-to-control ratio of 1:2 from healthy subjects who received health checkups in the same area. The visceral fat area (VFA) was calculated using CT images. Logistic regression analyses were performed to investigate the associations between EGJACs and obesity-related parameters.

RESULTS

In total, 74 EGJAC cases (62 males, median age of 70 years old) and 148 controls were extracted. Multivariable analyses showed a significantly negative association between the BMI and EGJACs and a significantly positive association between the VFA and EGJACs with odds ratios (ORs) (95% confidence intervals [CIs]) of 0.65 (0.53-0.80) and 1.01 (1.01-1.02), respectively. These findings were confirmed in another dataset (40 EGJACs and 80 controls). In addition, as a categorical variable, VFA ≥ 100 cm² showed a significantly positive association with EGJACs (OR [95% CI] 1.96 [1.02-3.76]).

CONCLUSIONS

We found paradoxical associations between EGJACs and obesity-related parameters (BMI vs. VFA) in a Japanese population, suggesting a potentially pivotal role of the VFA rather than the BMI as a risk factor for EGJACs.

Strong Intra-Esophageal Reflux May Contribute to the Development of Barrett's Adenocarcinoma and Affect the Localization

BACKGROUND

There has been no study that has directly measured the esophageal reflux factors in Barrett's adenocarcinoma (BA) using 24-h multichannel intraluminal impedance-pH monitoring (24-h MII-pH). We aimed to clarify the esophageal reflux factors in Barrett's esophagus (BE) and BA and the factors that determine the location of BA with 24-h MII-pH.

METHODS

We performed 24-h MII-pH in 26 patients with superficial BA treated endoscopically (BA group) and 13 patients with BE (BE group) and examined the esophageal reflux factors (esophageal acid exposure time [AET], bolus exposure (acid, weakly acid, and alkaline), and number of reflux episodes. In the BA group, there were 16 cases in which the lesions were localized in an area in contact with the esophagogastric junction (EGJ; EGJ group), and 10 cases in which the lesions were proximal to the BE and separated from the EGJ (non-EGJ group).

RESULTS

Total reflux in the bolus exposure in the BA group showed higher values compared to that in the BE group. The total of acid and weakly acid reflux of bolus exposure was significantly higher in the BA group than that in the BE group. The BA group also had greater numbers of total reflux episodes than the BE group. As for the cancer locations in BE, the cases in which the lesions were located proximally and separated from the EGJ had more AET and total reflux and acid reflux indicated by bolus exposure compared to the lesions adjacent to the EGJ.

CONCLUSIONS

Stronger gastro-esophageal reflux appeared to be an important factor in the development of adenocarcinoma from BE. In addition, the cancer location in BE may be related to the intensity of esophageal reflux.

Surgically resected primary esophageal choriocarcinoma accompanied with Barrett's adenocarcinoma: a case report

Background

Choriocarcinomas are usually classified as either gestational or non-gestational. Primary choriocarcinomas in the gastrointestinal tract, especially primary choriocarcinomas in the esophagus, are extremely rare. We report a case of a rare primary esophageal choriocarcinoma mixed with squamous cell carcinoma-like components in association with Barrett’s adenocarcinoma.

Case presentation

A 58-year-old man visited the hospital, complaining of hematemesis and tarry stools. In emergency upper gastrointestinal endoscopy, a bleeding esophageal tumor was observed. Additionally, a contrast computed tomography (CT) scan showed a large hypervascular tumor 4.8 cm in diameter in the left kidney. He came to our institution for further examination and treatment of the esophageal tumor and kidney lesion. The patient had an easy bleeding elevated tumor 2 cm in diameter at the left wall of the middle thoracic esophagus and a left renal carcinoma. Histopathological diagnosis of the biopsy specimen of the esophageal tumor was a poorly differentiated carcinoma. However, a precise histological type diagnosis could not be obtained. In June 2016, mediastinoscopic transhiatal esophagectomy and posterior mediastinal gastric tube reconstruction were performed to treat his esophageal tumor. Histopathologically, most of the tumor comprised hCG-positive syncytiotrophoblasts. Therefore, we confirmed it as a primary esophageal choriocarcinoma. Furthermore, the tumor contained a poorly differentiated squamous cell carcinoma-like component that was also diagnosed as a choriocarcinoma using immunohistochemical staining and there was a small Barrett’s esophageal adenocarcinoma lesion in the Barrett's epithelium near the tumor. Three months after surgery, a CT scan demonstrated multiple lung metastatic nodules and multiple intrahepatic masses. Needle biopsy from the lung nodule showed a choriocarcinoma. Despite chemotherapy, the metastatic choriocarcinoma regrew rapidly and multiple bone metastases appeared. He died because of his esophageal choriocarcinoma 13 months after primary resection.

Conclusions

We encountered an extremely rare case of esophageal choriocarcinoma combined with squamous cell carcinoma-like components in association with a simultaneous Barrett’s adenocarcinoma that we followed for the entire course of his disease, from resection to end of life. Esophageal choriocarcinomas are rare with peculiar characteristics and very poor prognoses. Additional cases are needed to establish an appropriate future treatment.

Time trends in the incidence of esophageal adenocarcinoma, gastric adenocarcinoma, and superficial esophagogastric junction adenocarcinoma

BACKGROUND

In Japan, the incidence of esophageal adenocarcinoma (EAC) and esophagogastric junction (EGJ) adenocarcinoma is expected to increase and that of gastric adenocarcinoma (GAC) is expected to decrease due to Westernization of the diet and the decreasing prevalence of Helicobacter pylori infection. However, few reports about these trends have included the latest data, and no reports about the time trend in the incidence of EGJ adenocarcinoma have focused on the etiologies (gastric cardia adenocarcinoma or EAC, including Barrett's adenocarcinoma). We therefore investigated the time trends in the incidence of these cancers by including the latest data.

METHODS

First, we investigated the time trends in EAC and GAC using population-based cancer registry data in Osaka Prefecture (1985-2014). We then investigated the time trend in superficial EGJ adenocarcinoma with clinicopathological features at Osaka International Cancer Institute (2006-2017).

RESULTS

From 1985 to 2014 in Osaka Prefecture, the incidence of EAC gradually increased in both sexes, while that of GAC in men did not significantly change and that in women decreased. The ratio of the EAC/GAC incidence increased 3.5 times in men and 1.8 times in women. In the secondary time trend survey for EGJ adenocarcinoma, the numbers of patients with endoscopic Barrett's esophagus and those without gastric mucosal atrophy increased, and the number of patients with lesions located above the EGJ line and histologically diagnosed as Barrett's adenocarcinoma increased.

CONCLUSIONS

The incidence of EAC and superficial EGJ adenocarcinoma with characteristics similar to those of EAC, including Barrett's adenocarcinoma, might be increasing.

Dickkopf-1 (DKK1) promotes tumor growth via Akt-phosphorylation and independently of Wnt-axis in Barrett's associated esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is still associated with poor prognosis, despite modern multi-modal therapies. New molecular markers, which control cell cycle and promote lymph node metastases or tumor growth, may introduce novel target therapies. Dickkopf-1 (DKK1) is a secreted glycoprotein that blocks the oncogenic Wnt/β-catenin signaling and its aberrant expression has been observed in many malignancies, including EAC. In this study, we investigated the biological role of DKK1 in EAC. Analysis of DKK1 and active β-catenin expression in human esophageal tissues confirmed a simultaneous DKK1-overexpression together with aberrant activation of β-catenin signaling in EAC in comparison with Barrett's and healthy mucosa. To elucidate the molecular role of DKK1, the OE33 adenocarcinoma cells, which were found to overexpress DKK1, were subjected to functional and molecular assays following siRNA-mediated DKK1-knockdown. At the functional level, OE33 cell viability, proliferation, migration and invasion were significantly attenuated by the absence of DKK1. At the molecular level, neither DKK1-knockdown nor application of exogenous recombinant DKK1 were found to alter the baseline β-catenin signaling in OE33 cells. However, DKK1-knockdown significantly abrogated downstream Akt-phosphorylation. On the other hand, the Wnt-agonist, Wnt3a, restored the Akt-phorphorylation in the absence of DKK1, without, however, being able to further stimulate β-catenin transcription. These findings suggest that the β-catenin transcriptional activity in EAC is independent of Wnt3a/DKK1 site-of-action and define an oncogenic function for DKK1 in this type of malignancy via distinct activation of Akt-mediated intracellular pathways and independently of Wnt-axis inhibition. Taken together, DKK1 may present a novel therapeutic target in EAC.

International development and validation of a classification system for the identification of Barrett's neoplasia using acetic acid chromoendoscopy: the Portsmouth acetic acid classification (PREDICT)

BACKGROUND

Barrett's oesophagus is an established risk factor for developing oesophageal adenocarcinoma. However, Barrett's neoplasia can be subtle and difficult to identify. Acetic acid chromoendoscopy (AAC) is a simple technique that has been demonstrated to highlight neoplastic areas but lesion recognition with AAC remains a challenge, thereby hampering its widespread use.

OBJECTIVE

To develop and validate a simple classification system to identify Barrett's neoplasia using AAC.

DESIGN

The study was conducted in four phases: phase 1-development of component descriptive criteria; phase 2-development of a classification system; phase 3-validation of the classification system by endoscopists; and phase 4-validation of the classification system by non-endoscopists.

RESULTS

Phases 1 and 2 led to the development of a simplified AAC classification system based on two criteria: focal loss of acetowhitening and surface patterns of Barrett's mucosa. In phase 3, the application of PREDICT (Portsmouth acetic acid classification) by endoscopists improved the sensitivity and negative predictive value (NPV) from 79.3% and 80.2% to 98.1% and 97.4%, respectively (p<0.001). In phase 4, the application of PREDICT by non-endoscopists improved the sensitivity and NPV from 69.6% and 75.5% to 95.9% and 96.0%, respectively (p<0.001).

CONCLUSION

We developed and validated a classification system known as PREDICT for the diagnosis of Barrett's neoplasia using AAC. The improvement seen in the sensitivity and NPV for detection of Barrett's neoplasia in phase 3 demonstrates the clinical value of PREDICT and the similar improvement seen among non-endoscopists demonstrates the potential for generalisation of PREDICT once proven in real time.

Endoscopic submucosal dissection in the era of proton pump inhibitors

Endoscopic submucosal dissection (ESD) has the advantage over endoscopic mucosa resection, permitting removal of gastrointestinal neoplasms en bloc, but is associated with relatively high risk of complications. Indications for early gastric cancer (EGC) are expanded: mucosal cancer without ulcer findings irrespective of tumor size; mucosal cancer with ulcer findings ≤3 cm in diameter; and minute submucosal invasive cancer ≤3 cm in size. The indications for early esophageal cancer (EEC) are the tumors confined to the two-third layer of the lamina propria. The EEC lesions spreading more than three-quarter of circumference of the esophagus are at frequent risk of stenosis. The procedures include marking, submucosal injection, circumferential mucosal incision and exforiation of the lesion along the submucosal layer. Complete ESD can achieve a large one-piece resection, allowing precise histological assessment to prevent recurrence. Clinical outcomes of gastric and esophageal ESD have been promising, and the prognosis of EGC patients treated by ESD is likely to be excellent, though further longer follow-up studies are warranted. Notification of perforation risk is essential in particular for esophageal ESD. Bleeding during ESD can be managed with coagulation forceps, and postoperative bleeding may be reduced with routine use of the stronger acid suppressant, proton pump inhibitors.