Clinical controversies in endoscopic ultrasound

Diagnostic Accuracy of Endoscopic Ultrasonography in Selecting Patients for Endoscopic Submucosal Dissection for Early Gastrointestinal Neoplasms

Tumor invasion depth and lymph node metastasis determine the prognosis of gastrointestinal (GI) neoplasms. GI neoplasms limited to mucosa (m1 or m2) and superficial submucosa (sm1) can be treated effectively with minimally invasive endoscopic therapy, while the deep invasion of the submucosa (sm2 or sm3) is associated with lymph node metastasis, and surgical resection is required. Correct staging is therefore crucial for preoperative evaluation and planning. Endoscopic ultrasonography (EUS) can be used to detect the depth of invasion due to its close proximity to the lesion. The diagnostic accuracy of EUS, when compared to conventional endoscopic staging, is debated as it can under- or overstage the lesion. We aim in this study to determine if EUS can accurately differentiate mucosal from submucosal GI neoplasms to select patients with early GI lesions for endoscopic submucosal dissection (ESD) or surgery. From March 2014 to February 2022, 293 patients with early superficial GI neoplasms were admitted to our endoscopic unit for EUS staging. To evaluate the accuracy of EUS, we compared the preoperative EUS findings with the definitive histopathologic findings on the resected specimen. Overall, 242 of 293 lesions were correctly staged by EUS (82.59%). In the evaluation of submucosal invasion or deeper, EUS understaged 38 of 293 (12.96%) and overstaged 13 of 293 (4.43%) lesions. EUS has excellent accuracy in staging superficial GI neoplasms; its use is highly recommended before ESD since it can also detect lymph node metastases around the lesions, thus changing the indication from ESD to surgery.

A Meta-Analysis And Systematic Review Of Accuracy Of Endoscopic Ultrasound For N Staging Of Gastric Cancers

BACKGROUND

Endoscopic ultrasonography (EUS) is widely used as a staging modality for gastric cancer. However, the results of studies on the use of EUS for N staging in gastric cancer vary. This study aimed at studying the overall diagnostic accuracy of EUS for N staging of gastric cancer.

METHODS

Published studies were identified through searching the MEDLINE, Web of Science, EMBASE, SpringerLink and ScienceDirect databases. A bivariate random effect model was used to estimate the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). A hierarchical summary receiver operating characteristic curves (HSROC) based on the pooled data was also computed.

RESULTS

Fifty studies (5223 patients) were included in this analysis. The pooled sensitivity, specificity, PLR, NLR and DOR of EUS for N staging were 0.82 (95% CI 0.78 to 0.85), 0.68 (0.63 to 0.73), 2.6 (2.2 to 3.0), 0.27 (0.22 to 0.32), and 10 (8 to 12), respectively. The area under the HSROC was 0.83.

CONCLUSION

The EUS may provide a clinically useful tool to guide physicians in the N staging of gastric cancer. However, physicians must note that the EUS has a relatively low specificity.

Minimally invasive staging of esophageal cancer

Esophageal cancer is one of the most common malignancies in the world today and the sixth-leading cause of cancer-related mortality. Accurate preoperative staging of esophageal cancer is imperative to the selection of appropriate treatments. Patients with esophageal carcinomas typically undergo a multimodality staging process including noninvasive imaging techniques, such as computed tomography (CT) and positron emission tomography (PET), as well as endoscopic ultrasound (EUS), which is slightly more invasive. Minimally invasive surgical staging, with laparoscopy, occasionally in combination with video-assisted thoracoscopy, is used in the staging process at select institutions and has been shown to be more accurate than noninvasive staging modalities. Two major advantages of minimally invasive surgical staging over conventional techniques are the improved assessment of locoregional disease and enhanced identification of distant metastases. These advantages decrease the likelihood that the patient will undergo a nontherapeutic laparotomy. Currently, no clear consensus exists regarding which patients with esophageal cancer would benefit most from the addition of minimally invasive surgical staging. We have, however, found that minimally invasive surgical staging with laparoscopy is particularly valuable in detection of occult distant metastases. In this article, we summarize the staging modalities for esophageal cancer including minimally invasive surgical staging.

Correlation between preoperative endoscopic ultrasound and surgical pathology staging of gastric adenocarcinoma: A single institution retrospective review

BACKGROUND

Recent evidence validates the effectiveness of neoadjuvant chemotherapy in the treatment of gastric adenocarcinoma. Endoscopic ultrasonographic (EUS) staging has been proposed as a useful adjunct in this setting.

METHODS

We performed a retrospective review of patients treated at our institution for gastric adenocarcinoma between July 2005 and January 2014. We identified patients referred for EUS before surgery as part of a prospective treatment plan. Histopathologic staging was compared to EUS staging, with a focus on T- and N-stage. Agreement between the two modalities was examined using kappa-statistics.

RESULTS

We identified 614 patients with biopsy-proven gastric adenocarcinoma; 145 underwent curative-intent surgery. Surgical pathology and EUS results were available from 69 patients. The accuracy of EUS for the evaluation of T- and N-stage was 44.9% and 56.5%, respectively. EUS demonstrated greater concordance with histopathology at evaluating T-stage (κ = 0.3469) than N-stage (κ = 0.1316). EUS underestimated T- and N-stage in 40.8% and 30.4% of patients, respectively.

CONCLUSION

EUS seems to correlate poorly with pathology in the preoperative staging of gastric adenocarcinoma. In the majority of inaccurate cases, EUS underestimates T-stage and N-stage, limiting its utility in the neoadjuvant setting.