Loco-regional staging accuracy in oesophageal cancer—How good are we in the modern era?

Imaging in Esophageal Cancer: A Comprehensive Review

Esophageal cancer is one of the common cancers. Risk factors are well recognized and lead most commonly to two distinct histological subtypes (squamous cell carcinoma and adenocarcinoma). The diagnosis is based on endoscopic evaluation. The most challenging aspect of management is accurate staging as it guides appropriate management. Endoscopic ultrasound, computed tomography (CT), positron emission tomography-CT, and magnetic resonance imaging are the imaging tests employed for the staging. Each imaging test has its own merits and demerits. Imaging is also critical to evaluate posttreatment complication and for response assessment. In this review article, we discuss in detail the risk factors, anatomical aspects, and role of imaging test in staging and evaluation of complications and response after treatment.

Multiple staging investigations may not change management in patients with high-grade dysplasia or early esophageal adenocarcinoma

The clinical value of multiple staging investigations for high-grade dysplasia or early adenocarcinoma of the esophagus is unclear. A single-center prospective cohort of patients treated for early esophageal cancer between 2000 and 2019 was analyzed. This coincided with a transition period from esophagectomy to endoscopic mucosal resection (EMR) as the treatment of choice. Patients were staged with computed tomography (CT), endoscopic ultrasound (EUS) and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) positron emission tomography(PET)/CT. The aim of this study was to assess their accuracy and impact on clinical management. 297 patients with high-grade dysplasia or early adenocarcinoma were included (endoscopic therapy/EMR n = 184; esophagectomy n = 113 [of which a 'combined' group had surgery preceded by endoscopic therapy n = 23]). Staging accuracy was low (accurate staging EMR: CT 40.1%, EUS 29.6%, FDG-PET/CT 11.0%; Esophagectomy: CT 43.3%, EUS 59.7%, FDG-PET/CT 29.6%; Combined: CT 28.6%, EUS46.2%, FDG-PET/CT 30.0%). Staging inaccuracies across all groups that could have changed management by missing T2 disease were CT 12%, EUS 12% and FDG-PET/CT 1.6%. The sensitivity of all techniques for detecting nodal disease was low (CT 12.5%, EUS 12.5%, FDG-PET/CT0.0%). Overall, FDG-PET/CT and EUS changed decision-making in only 3.2% of patients with an early cancer on CT and low-risk histology. The accuracy of staging with EUS, CT and FDG-PET/CT in patients with high-grade dysplasia or early adenocarcinoma of the esophagus is low. EUS and FDG-PET/CT added relevant staging information over standard CT in very few cases, and therefore, these investigations should be used selectively. Factors predicting the need for esophagectomy are predominantly obtained from EMR histology rather than staging investigations.

Esophageal cancer T-staging on MRI: A preliminary study using cine and static MR sequences

OBJECTIVES

To evaluate the added value of cine MR in addition to static MRI for T-Staging assessment of esophageal cancer (EC).

MATERIALS AND METHODS

This prospective monocentric study included 54 patients (mean age 66.3 ± 9.4 years, 46 men) with histologically proven EC. They underwent MRI on a 3 T-scanner in addition to the standard workup. Acquisitions included static and cine sequences (steady-state-free-precession and real-time True-FISP during water ingestion). Three radiologists independently assessed T-staging and diagnosis confidence by reviewing (1) static sequences (S-MRI) and (2) adding cine sequences (SC-MRI). Inter-reader agreement was performed. MRI T-staging was correlated to reference standard T-staging (histopathology or consensus on endoscopic ultrasonography and imaging findings) and to clinical outcome by log-rank test.

RESULTS

Both S-MRI and SC-MRI T-staging showed a significant correlation with reference T-staging (rs = 0.667, P < 0.001). SC-MRI showed a slightly better performance in distinguishing T1-T3 from T4 with a sensitivity, specificity and AUC of 76.5% (95% CI: 50.1-93.2), 83.8% (68-93.8) and 0.801 (0.681-0.921) vs 70.6% (44-89.7), 83% (68-93.8) and 0.772 (0.645-0.899) for S-MRI. Compared to S-MRI, SC-MRI increased inter-reader agreement for T4a and T4b (κ = 0.403 and 0.498) and T-staging confidence.

CONCLUSION

MRI is accurate for T-staging of EC. The addition of cine sequences allows better differentiation between T1-T3 and T4 tumors with increased diagnostic confidence and inter-reader agreement.

Linear EUS Accuracy in Preoperative Staging of Gastric Cancer: A Retrospective Multicenter Study

INTRODUCTION

Preoperative gastric cancer (GC) staging is the most reliable prognostic factor that affects therapeutic strategies. Contrast-enhanced computed tomography (CECT) and radial endoscopic ultrasound (R-EUS) scans are the most commonly used staging tools for GC. The accuracy of linear EUS (L-EUS) in this setting is still controversial. The aim of this retrospective multicenter study was to evaluate the accuracy of L-EUS and CECT in preoperative GC staging, with regards to depth of tumor invasion (T staging) and nodal involvement (N staging).

MATERIALS AND METHODS

191 consecutive patients who underwent surgical resection for GC were retrospectively enrolled. Preoperative staging had been performed using both L-EUS and CECT, and the results were compared to postoperative staging by histopathologic analysis of surgical specimens.

RESULTS

L-EUS diagnostic accuracy for depth of invasion of the GC was 100%, 60%, 74%, and 80% for T1, T2, T3, and T4, respectively. CECT accuracy for T staging was 78%, 55%, 45%, and 10% for T1, T2, T3, and T4, respectively. L-EUS diagnostic accuracy for N staging of GC was 85%, significantly higher than CECT accuracy (61%).

CONCLUSIONS

Our data suggest that L-EUS has a higher accuracy than CECT in preoperative T and N staging of GC.

Clinical Understaging, Treatment Response, and Survival Among Esophageal Adenocarcinoma Patients

INTRODUCTION

Selecting appropriate management for patients with esophageal adenocarcinoma (EA) is predicated on accurate clinical staging information. Inaccurate information could lead to inappropriate treatment and suboptimal survival. We investigated the relationship between staging accuracy, treatment, and survival.

METHODS

This was a national cohort study of EA patients in the National Cancer Data Base (2006-2015) treated with upfront resection or neoadjuvant therapy (NAT). Clinical and pathological staging information was used to ascertain staging concordance for each patient. For NAT patients, Bayesian analysis was used to account for potential downstaging. We evaluated the association between staging concordance, receipt of NAT, and survival through hierarchical logistic regression and multivariable Cox regression.

RESULTS

Among 7635 EA patients treated at 877 hospitals, 3038 had upfront resection and 4597 NAT followed by surgery. Relative to accurately staged patients, understaging was associated with a lower likelihood (odds ratio [OR] 0.04 95% confidence interval [CI] 0.02-0.05) while overstaging was associated with a greater likelihood of receiving NAT (OR 1.98 [1.53-2.56]). Relative to upfront surgery, treatment of cT1N0 patients with NAT was associated with a higher risk of death (HR 3.08 [2.36-4.02]). For accurately or overstaged cT3-T4 patients, NAT was associated with a lower risk of death whether downstaging occurred (ypN0 disease-HR 0.67 [0.49-0.92]; N+ disease-HR 0.55 [0.45-0.66]) or not (ypN + disease-HR 0.78 [95% CI 0.65-0.93]).

CONCLUSIONS

Clinical understaging is associated with receipt of NAT which in turn may have a stage-specific impact on patients' survival regardless of treatment response. Guidelines should account for the possibility of inaccurate clinical staging.

ACR Appropriateness Criteria® Staging and Follow-Up of Esophageal Cancer

This document provides recommendations regarding the role of imaging in the staging and follow-up of esophageal cancer. For initial clinical staging, locoregional extent and nodal disease are typically assessed with esophagogastroduodenoscopy and esophageal ultrasound. FDG-PET/CT or CT of the chest and abdomen is usually appropriate for use in initial clinical staging as they provide additional information regarding distant nodal and metastatic disease. The detection of metastatic disease is critical in the initial evaluation of patients with esophageal cancer because it will direct patients to a treatment pathway centered on palliative radiation rather than surgery. For imaging during treatment, particularly neoadjuvant chemotherapy, FDG-PET/CT is usually appropriate, because some studies have found that it can provide information regarding primary lesion response, but more importantly it can be used to detect metastases that have developed since the induction of treatment. For patients who have completed treatment, FDG-PET/CT or CT of the chest and abdomen is usually appropriate for evaluating the presence and extent of metastases in patients with no suspected or known recurrence and in those with a suspected or known recurrence. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Potential Clinical Utility of a Targeted Circulating Tumor DNA Assay in Esophageal Adenocarcinoma

OBJECTIVE

To explore the clinical utility of circulating tumor DNA (ctDNA) in esophageal adenocarcinoma (EAC) by developing a cost-effective and rapid technique utilising targeted amplicon sequencing.

SUMMARY OF BACKGROUND DATA

Emerging evidence suggests that levels of ctDNA in the blood can be used to monitor treatment response and in the detection of disease recurrence in various cancer types. Current staging modalities for EAC such as computerised tomography of the chest/abdomen/pelvis (CT) and positron emission tomography (PET) do not reliably detect occult micro-metastatic disease, the presence of which signifies a poor prognosis. After curative-intent treatment, some patients are still at high risk of recurrent disease, and there is no widely accepted optimal surveillance tool for patients with EAC.

METHODS

Sixty-two patients with EAC were investigated for the presence of ctDNA using a tumor-informed approach. We designed a custom targeted amplicon sequencing panel of target specific primers covering mutational foci in 9 of the most commonly mutated genes in EAC. Serial blood samples were taken before and after neoadjuvant treatment (NAT), and during surveillance.

RESULTS

Somatic mutations were detected in pre-treatment biopsy samples of 55 out of 62 (89%) EAC patients. Mutations in TP53 (80%) were the most common. Out of these 55 patients, 20 (36%) had detectable ctDNA at baseline. The majority (90%) of patients with detectable ctDNA had either locally advanced tumors, nodal involvement or metastatic disease. In patients with locally advanced tumors, disease free survival (DFS) was more accurately stratified using pre-treatment ctDNA status [HR 4.34 (95% CI 0.93-20.21); P = 0.05] compared to nodal status on PET-CT. In an exploratory subgroup analysis, patients who are node negative but ctDNA positive have inferior DFS [HR 11.71 (95% CI 1.16-118.80) P = 0.04]. In blood samples taken before and following NAT, clearance of ctDNA after NAT was associated with a favourable response to treatment. Furthermore, patients who are ctDNA positive during post-treatment surveillance are at high risk of relapse.

CONCLUSIONS

Our study shows that ctDNA has potential to provide additional prognostication over conventional staging investigation such as CT and PET. It may also have clinical utility in the assessment of response to NAT and as a biomarker for the surveillance of recurrent disease.

Surgical Management of Early Esophageal Cancer

Esophageal cancer is the eighth most common cancer worldwide, and its incidence has been increasing over the past several decades. Esophagectomy currently is the standard of care for more advanced early esophageal cancer and should be performed at centers of excellence with high volumes, appropriate supportive staff, and multidisciplinary expertise.

Diagnostic Performance of MRI for Esophageal Carcinoma: A Systematic Review and Meta-Analysis

Background Although CT, endoscopic US, and PET are critical in determining the appropriate management of esophageal carcinoma (squamous cell carcinoma and adenocarcinoma), previous reports show that staging accuracy remains low, particularly for nodal involvement sensitivity. Purpose To perform a systematic review and meta-analysis to determine the diagnostic performance of MRI for multiple staging thresholds in patients with biopsy-proven esophageal carcinoma (differentiation of stage T0 disease from stage T1 or higher disease, differentiation of stage T2 or lower disease from stage T3 or higher disease, and differentiation of stage N0 disease from stage N1 or higher disease [where T refers to tumor stage and N refers to nodal stage]). Materials and Methods Studies of the diagnostic performance of MRI in determining the stage of esophageal carcinoma in patients before esophagectomy and pathologic staging between 2000 and 2019 were searched in PubMed, Scopus, Web of Science, and Cochrane Library by a librarian and radiation oncologist. Pooled diagnostic performance of MRI was calculated with a bivariate random effects model. Bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (version 2) tool. Results Twenty studies with a total of 984 patients were included in the analysis. Pooled accuracy for stage T0 versus stage T1 or higher had a sensitivity of 92% (95% CI: 82, 96) and a specificity of 67% (95% CI: 51, 81). Pooled accuracy for stage T2 or lower versus stage T3 or higher had a sensitivity of 86% (95% CI: 76, 92) and a specificity of 86% (95% CI: 75, 93). Pooled accuracy for stage N0 versus stage N1 or higher had a sensitivity of 71% (95% CI: 60, 80) and a specificity of 72% (95% CI: 64, 79). The concern for applicability was low for the patient selection, index test, and reference test domains, except for 10% of studies (two of 20) that had unclear concern for patient selection applicability. Conclusion MRI has high sensitivity but low specificity for the detection of esophageal carcinoma, which shows promise for determining neoadjuvant therapy response and for detecting locally advanced disease for potential trimodality therapy. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Leeflang in this issue.

Staging Concordance and Guideline-Concordant Treatment for Esophageal Adenocarcinoma

BACKGROUND

Treatment selection for patients with esophageal adenocarcinoma is predicated on clinical staging information, which is inaccurate in 20% to 30% of cases and could impact the delivery of guideline-concordant treatment. We aimed to evaluate the association between staging concordance at the patient and hospital levels with the delivery of guideline-concordant treatment among esophageal adenocarcinoma patients.

METHODS

This was a national cohort study of resected esophageal adenocarcinoma patients in the National Cancer Data Base (2006 to 2015) treated either with upfront resection or neoadjuvant therapy followed by surgery. Patient- and hospital-level clinical and pathologic staging concordance and deviations from treatment guidelines were ascertained. For neoadjuvant therapy patients, staging concordance was predicted through Bayesian analysis. Reliability adjustment was used when evaluating hospital-level concordance.

RESULTS

Among 9393 esophageal adenocarcinoma patients treated at 927 hospitals, 41% had upfront surgery. Among upfront surgery patients, staging concordance was 85.1% for T1N0 and 86.9% for T3-T4N+ disease, but less than 50% for all others. Among patients treated with neoadjuvant therapy, treatment downstaging was observed in 33.9%. Deviations from treatment guidelines were identified in 38.5% of upfront surgery patients and 3.3% of neoadjuvant therapy patients. The proportion of concordantly staged patients ranged from 60.1% to 87.9%, and deviations from treatment guidelines were observed among 14.9% to 22.7% of the patients. Patient staging concordance increased, and deviations from guidelines decreased, as hospital-level concordance increased (trend test, P values less than .001 for all).

CONCLUSIONS

Deviations from treatment guidelines in esophageal adenocarcinoma patients appear to be a function of inaccurate clinical staging information, which should be a new focus for quality improvement efforts.

The role of primary tumor SUVmax in the diagnosis of invasion depth: a step toward clinical T2N0 esophageal cancer

Background

The controversy regarding optimal clinical T2N0 esophageal cancer treatment ultimately stems from the clinical staging modalities’ inaccuracy. Because most inaccuracies lie in clinical T2 to pathological T1, it is vital to discriminate whether the muscularis propria is invaded.

Methods

We investigated the association between the primary tumor maximal standard uptake value (SUVmax), and the pathological features and overall survival. We attempted to construct a discriminative model through logistic regression analysis.

Results

A total of 140 cN0 esophageal squamous cell carcinoma (ESCC) patients were enrolled. Primary tumor SUVmax differed significantly in paired pathological T categories (P<0.05), but not pT2 vs. pT3 (P=0.648). Age (≤65 vs. >65), biopsy differentiation grades (well or moderately vs. poorly vs. unknown), and primary tumor SUVmax (continuous) were independent risk factors for invasion depth. Subsequently, the age categories, the biopsy differentiation grade categories, and the primary tumor SUVmax categories (≤7.4 vs. >7.4) were included in the logistic regression analysis to construct a discriminative model, showing a good performance in discriminating pT2–3 vs. pT1 in terms of accuracy 87.1%, sensitivity 93.6%, specificity 73.9%, and area under the curve (AUC) 0.887 [95% confidence interval (CI): 0.822 to 0.951]. Of these factors, biopsy differentiation grades and primary tumor SUVmax showed significant differences in overall survival (P<0.05), while the age categories did not.

Conclusions

The novel baseline model comprised of age, biopsy differentiation grades, and primary tumor SUVmax provide much discriminative performance in determining whether the muscularis propria is invaded. Further studies are necessary to validate the findings and guide clinical practice for cT2N0 esophageal cancer.

Prediction of lymph node metastases using pre-treatment PET radiomics of the primary tumour in esophageal adenocarcinoma: an external validation study

OBJECTIVES

To improve clinical lymph node staging (cN-stage) in oesophageal adenocarcinoma by developing and externally validating three prediction models; one with clinical variables only, one with positron emission tomography (PET) radiomics only, and a combined clinical and radiomics model.

METHODS

Consecutive patients with fluorodeoxyglucose (FDG) avid tumours treated with neoadjuvant therapy between 2010 and 2016 in two international centres (n = 130 and n = 60, respectively) were included. Four clinical variables (age, gender, clinical T-stage and tumour regression grade) and PET radiomics from the primary tumour were used for model development. Diagnostic accuracy, area under curve (AUC), discrimination and calibration were calculated for each model. The prognostic significance was also assessed.

RESULTS

The incidence of lymph node metastases was 58% in both cohorts. The areas under the curve of the clinical, radiomics and combined models were 0.79, 0.69 and 0.82 in the developmental cohort, and 0.65, 0.63 and 0.69 in the external validation cohort, with good calibration demonstrated. The area under the curve of current cN-stage in development and validation cohorts was 0.60 and 0.66, respectively. For overall survival, the combined clinical and radiomics model achieved the best discrimination performance in the external validation cohort (X² = 6.08, df = 1, p = 0.01).

CONCLUSION

Accurate diagnosis of lymph node metastases is crucial for prognosis and guiding treatment decisions. Despite finding improved predictive performance in the development cohort, the models using PET radiomics derived from the primary tumour were not fully replicated in an external validation cohort.

ADVANCES IN KNOWLEDGE

This international study attempted to externally validate a new prediction model for lymph node metastases using PET radiomics. A model combining clinical variables and PET radiomics improved discrimination of lymph node metastases, but these results were not externally replicated.

Hospital clinical staging accuracy for upper gastrointestinal malignancy

BACKGROUND

Decisions about multimodality treatment for upper gastrointestinal malignancies are largely predicted on clinical staging information. However, hospital-level accuracy of clinical staging is currently unknown.

METHODS

A national cohort study of patients with adenocarcinoma of the esophagus, stomach, or pancreas in the NCDB (2006-2015) who were treated with upfront resection. Hospital-level staging accuracy (ascertained by comparing clinical stage to pathologic stage) was calculated. Within hospital correlation of staging accuracy across disease sites was evaluated using risk and reliability adjustment.

RESULTS

Overall, 1246 hospitals were evaluated. Median hospital T-staging accuracy was 77.5%, 73.7%, and 60.8% for esophageal, gastric, and pancreatic cancer, respectively. Median hospital N-staging accuracy was 80.2%, 72.9%, and 61.8%, respectively. For T-stage, over-staging was most frequently observed in esophageal patients (11.2%) while under-staging was most frequent in pancreatic patients (36.1%). For N-stage, over-staging was infrequent for all three, while under-staging was most common in pancreatic patients (37.4%). Correlation across disease sites was weak for both T- (best observed, r = .34) and N-stages (r = .30). When high volume hospitals were evaluated, correlation improved but accuracy rates were similar.

CONCLUSIONS

Despite the importance of clinical staging in multimodality treatment planning, hospitals inaccurately stage 20-40% of patients, with low correlation across disease sites.

Role of precision imaging in esophageal cancer

Esophageal cancer is a major cause of morbidity and mortality worldwide. Recent advancements in the management of esophageal cancer have allowed for earlier detection, improved ability to monitor progression, and superior treatment options. These innovations allow treatment teams to formulate more customized management plans and have led to an increase in patient survival rates. For example, in order for the most effective management plan to be constructed, accurate staging must be performed to determine tumor resectability. This article reviews the multimodality imaging approach involved in making a diagnosis, staging, evaluating treatment response and detecting recurrence in esophageal cancer.

Discordant nodal staging identifies intermediate-risk group for overall survival in patients with cT3 oesophageal adenocarcinoma

OBJECTIVES

Oesophageal adenocarcinoma has a poor prognosis and relies on multi-modality assessment for accurate nodal staging. The aim of the study was to determine the prognostic significance of nodal concordance between PET/CT and EUS in oesophageal adenocarcinoma.

METHODS

Consecutive patients with oesophageal adenocarcinoma staged between 2010 and 2016 were included. Groups comprising concordant node-negative (C-ve), discordant (DC), and concordant node-positive (C+ve) patients were analysed. Survival analysis using log-rank tests and Cox proportional hazards model was performed. The primary outcome was overall survival. A p value < 0.05 was considered statistically significant.

RESULTS

In total, 310 patients (median age = 66.0; interquartile range 59.5-72.5, males = 264) were included. The median overall survival was 23.0 months (95% confidence intervals (CI) 18.73-27.29). There was a significant difference in overall survival between concordance groups (X² = 44.91, df = 2, p < 0.001). The hazard ratios for overall survival of DC and C+ve patients compared with those of C-ve patients with cT3 tumours were 1.21 (95% CI 0.81-1.79) and 1.79 (95% CI 1.23-2.61), respectively. On multivariable analysis, nodal concordance was significantly and independently associated with overall survival (HR 1.44, 95% CI 1.12-1.83, p = 0.004) and performed better than age at diagnosis (HR 1.02, 95% CI 1.003-1.034, p = 0.016) and current cN-staging methods (HR 1.20, 95% CI 0.978-1.48, p = 0.080).

CONCLUSIONS

Patients with discordant nodal staging on PET/CT and EUS represent an intermediate-risk group for overall survival. This finding was consistent in patients with cT3 tumours. These findings will assist optimum treatment decisions based upon perceived prognosis for each patient.

KEY POINTS

• Clinicians are commonly faced with results of discordant nodal staging in oesophageal adenocarcinoma. • There is a significant difference in overall survival between patients with negative, discordant, and positive lymph node staging. • Patients with discordant lymph node staging between imaging modalities represent an intermediate-risk group for overall survival.