Can CT-PET and Endoscopic Assessment Post-Neoadjuvant Chemoradiotherapy Predict Residual Disease in Esophageal Cancer?

Advances in the Imaging of Esophageal and Gastroesophageal Junction Malignancies

Accurate imaging is key for the diagnosis and treatment of esophageal and gastroesophageal junction cancers . Current imaging modalities, such as computed tomography (CT) and 18F-FDG (2-deoxy-2-[18F]fluoro-D-glucose) positron emission tomography (PET)/CT, have limitations in accurately staging these cancers. MRI shows promise for T staging and residual disease assessment. Novel PET tracers, like FAPI, FLT, and hypoxia markers, offer potential improvements in diagnostic accuracy. 18F-FDG PET/MRI combines metabolic and anatomic information, enhancing disease evaluation. Radiomics and artificial intelligence hold promise for early detection, treatment planning, and response assessment. Theranostic nanoparticles and personalized medicine approaches offer new avenues for cancer therapy.

18F-FDG-PET/CT to Detect Pathological Complete Response After Neoadjuvant Treatment in Patients with Cancer of the Esophagus or Gastroesophageal Junction: Accuracy and Long-Term Implications

PURPOSE

The curative strategy for patients with esophageal cancer without distant metastases consists of esophagectomy with preceding chemo(radio)therapy (CRT). In 10-40% of patients treated with CRT, no viable tumor is detectable in the resection specimen (pathological complete response (pCR)). This study aims to define the clinical outcomes of patients with a pCR and to assess the accuracy of post-CRT FDG-PET/CT in the detection of a pCR.

METHODS

Four hundred sixty-three patients with cancer of the esophagus or gastroesophageal junction who underwent esophageal resection after CRT between 1994 and 2013 were included. Patients were categorized as pathological complete responders or noncomplete responders. Standardized uptake value (SUV) ratios of 135 post-CRT FDG-PET/CTs were calculated and compared with the pathological findings in the corresponding resection specimens.

RESULTS

Of the 463 included patients, 85 (18.4%) patients had a pCR. During follow-up, 25 (29.4%) of these 85 patients developed recurrent disease. Both 5-year disease-free survival (5y-DFS) and 5-year overall survival (5y-OS) were significantly higher in complete responders compared to noncomplete responders (5y-DFS 69.6% vs. 44.2%; P = 0.001 and 5y-OS 66.5% vs. 43.7%; P = 0.001). Not pCR, but only pN0 was identified as an independent predictor of (disease-free) survival.

CONCLUSION

Patients with a pCR have a higher probability of survival compared to noncomplete responders. One third of patients with a pCR do develop recurrent disease, and pCR can therefore not be equated with cure. FDG-PET/CT was inaccurate to predict pCR and therefore cannot be used as a sole diagnostic tool to predict pCR after CRT for esophageal cancer.

Neoadjuvant PD-1 blockade combined with chemotherapy is not superior to neoadjuvant chemotherapy alone in resectable locally advanced esophageal carcinoma

BACKGROUND

Neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy followed by surgery has been recommended as standard treatment in patients with locally advanced esophageal cancer (LAEC). But the risk of tumor recurrence still remained, and many patients refused or abandoned radiotherapy because of the intolerable adverse effects in China. Neoadjuvant immunochemotherapy (nICT) followed by surgery has become an emerging treatment in patients with esophageal cancer. There was still no consensus on whether nICT was superior to nCT alone in patients with esophageal cancer.

METHODS

In this retrospective study, patients with resectable esophageal cancer who received surgery after nICT (n=26, 40%) or nCT alone (n=39, 60%) were included. The patients were classified as nICT or nCT arm. The primary endpoints were pathological tumor response (PTR) and event-free survival (EFS). The different clinic-pathological features were compared by the Kruskal-Wallis test for continuous variables and the Chi-square (χ²) test for categorical variables. Kaplan-Meier curves were used to estimate EFS from the date of treatment to recurrence or death. All tests were 2-sided with a significative P-value defined <.05.

RESULTS

Three (11.5%) of the 26 patients achieved pathological complete remission (pCR) in the nICT group, and four (10.3%) of the 39 patients achieved pCR in the nCT group, respectively (P=1.000). Six (23.1%) of the 26 patients achieved major pathological response (MPR) in the nICT group, and 11 (28.2%) of the 39 patients achieved MPR in the nCT group, respectively (P=0.645). Downstaging was achieved in 13 (44.8%) patients in the nICT group and 16 (55.2%) patients in the nCT group, respectively (P=0.732). To verify the tumor regression grade (TRG) results, we compared them with MPR and pCR, which showed a significant dependency (P< 0.001). Patients who achieved downgrading showed better MPR and pCR rates (P<0.001 and P =0.010). There was no significant difference in EFS between the nICT and nCT groups (HR=1.011, 95% CI: 0.421-2.425, P = 0.981).

CONCLUSIONS

Neoadjuvant PD-1 blockade combined with chemotherapy was not superior to chemotherapy alone for patients with resectable locally advanced esophageal carcinoma. However, more studies with long-term follow-up were needed to confirm this result.

Clinical Utility of Circulating Tumor Cells for Predicting Major Histopathological Response after Neoadjuvant Chemoradiotherapy in Patients with Esophageal Cancer

Background: A “surgery as needed” approach may be offered to patients with esophageal cancer (EC) who achieve major histopathological response (MaHR) after neoadjuvant chemoradiotherapy (nCRT). However, the utility of clinical response assessment (CRE) for predicting histopathological response to nCRT remains limited. Circulating tumor cells (CTCs) hold promise as biomarkers of response to nCRT. Methods: We analyzed the clinical utility of post-nCRT CTCs, alone or in combination with CRE, in the prediction of MaHR. We defined MaHR as either the lack or a limited presence (≤10%) of vital residual tumor cells in the resected esophageal specimen in the absence of nodal involvement. Results: Of the 48 study patients, 27 (56%) achieved MaHR. Patients with MaHR had a significantly lower CTCs count compared with those without (3.61 ± 4.53 versus 6.83 ± 5.22 per mL of blood, respectively; P = 0.027). Using a cutoff for positivity of 5 CTCs per mL of blood, the combination of CTCs and CRE allowed achieving a negative predictive value for MaHR of 93% (95% confidence interval [CI] = 70–99%) along with a false negative rate of 5% (95% CI = 1–33%). Conclusion: CTCs count assessed in combination with CRE can potentially help identify patients with EC who achieved MaHR after nCRT.

The Key Clinical Questions of Neoadjuvant Chemoradiotherapy for Resectable Esophageal Cancer—A Review

Over 50% of individuals with esophageal cancer (EC) present with advanced stages of the disease; therefore, their outcome following surgery alone is poor, with only 25%–36% being alive 5 years post-surgery. Based on the evidence that the CROSS and NEOCRTEC5010 trials provided, neoadjuvant chemoradiotherapy (nCRT) is now the standard therapy for patients with locally advanced EC. However, there are still many concerning clinical questions that remain controversial such as radiation dose, appropriate patient selection, the design of the radiation field, the time interval between chemoradiotherapy (CRT) and surgery, and esophageal retention. With immune checkpoint inhibitors (ICIs) rapidly becoming a mainstay of cancer therapy, along with radiation, chemotherapy, and surgery, the combination mode of immunotherapy is also becoming a hot topic of discussion. Here, we try to provide constructive suggestions to answer the perplexing problems and clinical concerns for the progress of nCRT for EC in the future.

Definitive chemoradiotherapy versus neoadjuvant chemoradiotherapy followed by surgery in patients with locally advanced esophageal squamous cell carcinoma who achieved clinical complete response when induction chemoradiation finished: A phase II random

BACKGROUND AND PURPOSE

More than 40% of patients with esophageal squamous cell carcinoma (ESCC) exhibit pathological complete responses (pCR) after neoadjuvant chemoradiotherapy (nCRT), and theoretically, these patients may be cured by CRT and omit surgery. This prospectively randomized pilot study compared definitive chemoradiotherapy (dCRT) with nCRT in patients with locally advanced ESCC who achieved clinical complete responses (cCRs) to nCRT.

MATERIALS AND METHODS

Single center, randomized, open phase 2 study of 256 patients with locally advanced ESCC enrolled between April 2016 and November 2018. Immediately when nCRT finished, patients enrolled underwent response evaluations within 1 week. Patients with cCR were randomly allocated to undergo surgery (arm A) or complete CRT up to the definitive radiation dose (arm B). The primary end point was 3-year disease-free survival (DFS).

RESULTS

Finally, 71 patients were randomly assigned to the nCRT (n = 36) and dCRT (n = 35) arms. The median observation time was 35.7 months. The 3-year DFS rate was 56.43% in arm A versus 54.73% in arm B (hazard ratio [HR] = 0.862, 95% confidence interval [CI] = 0.452 to 1.645, P = 0.652). The 3-year overall survival (OS) rates in arms A and B were 69.5% and 62.3% (HR = 0.824, 95% CI = 403-1.688, P = 0.597), respectively.

CONCLUSIONS

According to our treatment response evaluation criteria, survival of the patients with cCR after nCRT was not significant different between nCRT group and dCRT group. An optimized response evaluation strategy soon after nCRT may guide next therapy decisions for patients with locally advanced ESCC.

18F-FDG-PET/CT-measured parameters as potential predictors of residual disease after neoadjuvant chemoradiotherapy in patients with esophageal carcinoma

Objective

To evaluate the maximum and mean standardized uptake values, together with the metabolic tumor value and the total lesion glycolysis, at the primary tumor site, as determined by ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG-PET/CT), performed before and after neoadjuvant chemoradiotherapy (nCRT), as predictors of residual disease (RD) in patients with esophageal cancer.

Materials and Methods

The standardized uptake values and the volumetric parameters (metabolic tumor value and total lesion glycolysis) were determined by ¹⁸F-FDG-PET/CT to identify RD in 39 patients before and after nCRT for esophageal carcinoma. We used receiver operating characteristic curves to analyze the diagnostic performance of ¹⁸F-FDG-PET/CT parameters in the definition of RD. The standard of reference was histopathological analysis of the surgical specimen.

Results

Eighteen patients (46%) presented RD after nCRT. Statistically significant areas under the curve (approximately 0.72) for predicting RD were obtained for all four of the variables evaluated after nCRT. Considering the presence of visually detectable uptake (higher than the background level) at the primary tumor site after nCRT as a positive result, we achieved a sensitivity of 94% and a specificity of 48% for the detection of RD.

Conclusion

The use of ¹⁸F-FDG-PET/CT can facilitate the detection of RD after nCRT in patients with esophageal cancer.

Advances in the curative management of oesophageal cancer

The incidence of oesophageal cancer, in particular adenocarcinoma, has markedly increased over the last four decades with adenocarcinoma becoming the dominant subtype in the West, and mortality rates are high. Nevertheless, overall survival of patients with oesophageal cancer has doubled in the past 20 years, with earlier diagnosis and improved treatments benefiting those patients who can be treated with curative intent. Advances in endotherapy, surgical approaches, and multimodal and other combination therapies have been reported. New vistas have emerged in targeted therapies and immunotherapy, informed by new knowledge in genomics and molecular biology, which present opportunities for personalised cancer therapy and novel clinical trials. This review focuses exclusively on the curative intent treatment pathway, and highlights emerging advances.

The Role of Magnetic Resonance Imaging in the Management of Esophageal Cancer

Esophageal cancer (EC) is the eighth more frequent cancer worldwide, with a poor prognosis. Initial staging is critical to decide on the best individual treatment approach. Current modalities for the assessment of EC are irradiating techniques, such as computed tomography (CT) and positron emission tomography/CT, or invasive techniques, such as digestive endoscopy and endoscopic ultrasound. Magnetic resonance imaging (MRI) is a non-invasive and non-irradiating imaging technique that provides high degrees of soft tissue contrast, with good depiction of the esophageal wall and the esophagogastric junction. Various sequences of MRI have shown good performance in initial tumor and lymph node staging in EC. Diffusion-weighted MRI has also demonstrated capabilities in the evaluation of tumor response to chemoradiotherapy. To date, there is not enough data to consider whole body MRI as a routine investigation for the detection of initial metastases or for prediction of distant recurrence. This narrative review summarizes the current knowledge on MRI for the management of EC.

PET Imaging and Rate of Pathologic Complete Response in Esophageal Squamous Cell Carcinoma

BACKGROUND

For locally advanced esophageal squamous cell carcinoma (ESCC), chemoradiation (ChemoRT) followed by surgery offers the best chance of cure, with a 35-50% pathologic complete response (pCR) rate. Given the morbidity of esophagectomy and the possibility of pCR with ChemoRT, a 'watch and wait' strategy has been proposed, particularly for squamous cell carcinoma. The ability to accurately predict which patients will have pCR from ChemoRT is critical in treatment decision making. This study assessed positron emission tomography (PET) in predicting pCR after neoadjuvant ChemoRT for ESCC.

METHODS

ESCC patients treated with ChemoRT followed by surgery were identified. Maximum standard uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and first-order textual features of standard deviation, kurtosis and skewness were measured from PET. Univariable and multivariable generalized linear method analyses were performed. A metabolic complete response (mCR) was defined as a post-therapy PET scan with maximum SUV < 4.0.

RESULTS

Twenty-seven patients underwent ChemoRT followed by surgery, with overall pCR seen in 11 (41%) patients and radiographic mCR seen in 12 (44%) patients. Final pathology for these 12 patients revealed pCR (ypT0N0M0) in 5 (42%) patients and persistent disease in 7 (58%) patients. Univariate analysis did not reveal PET parameters predictive of pCR.

CONCLUSION

Treatment of ESCC with ChemoRT often results in a robust clinical response. Among patients with an mCR after ChemoRT, disease persistence was found in 58%. The inability of PET to predict pCR is important in the context of a 'watch and wait' strategy for ESCC treated with ChemoRT.

Efficacy and safety of neoadjuvant chemotherapy and immunotherapy in locally resectable advanced esophageal squamous cell carcinoma

Background

Esophageal squamous cell cancer (ESCC) patients with the potentially resectable disease most would experience relapse after surgery. Immunotherapy has been reported to improve the prognosis of advanced esophageal cancer and may be a new strategy to prevent this urgent condition's recurrence. We first evaluated the efficacy and safety of neoadjuvant chemotherapy combined with immunotherapy in patients with resectable ESCC.

Methods

All patients with resectable locally advanced ESCC (clinical stage III-IVB). Received at least 1 cycle of neoadjuvant chemotherapy combined with immunotherapy (NACI), and the interval between each cycle and the operation should be at least 3 weeks. All patients were treated with standard surgery. The tumor imaginations were obtained at baseline and within a week before surgery. The efficacy endpoint was the rate of major pathologic response (MPR, 10% viable tumor cells). Expression of immunohistochemical-related molecules was investigated in surgical samples.

Results

A total of 38 patients with ESCC were included (36 males, median age 61 years), and most of them used Pembrolizumab (55.26%) and Camrelizumab (31.58%). We analyzed 19 patients and found that 13 patients (68.42%) achieved radiological partial response (PR) by CT images. R0 resection was performed in 35 patients (92.11%), and 10 patients (26.32%) developed postoperative complications. Through postoperative pathology, we found 13 (34.21%) patients had complete pathologic response (cPR), and 16 (42.11%) patients achieved MPR. We also found that none of the factors had a statistically significant impact on MPR. Still, the regression rate of Sum of lesion diameter (SLD) was significantly positively correlated with the pathological remission rate (P=0.012, r=0.565).

Conclusions

The rate of MPR in ESCC patients reached 42.11%. The use of the NACI regimen did not increase the occurrence of complications in neoadjuvant treatment and operation, and the SLD regression rate has a certain guiding significance for the effect of immunotherapy.

Prediction of the tumor response and survival based on computed tomography in esophageal squamous cell carcinoma after trimodality therapy

PURPOSE

Predicting the response to neoadjuvant chemoradiotherapy (NCRT) and the prognosis of esophageal squamous cell carcinoma (ESCC) is challenging. This study evaluated the potential of a preoperative computed tomography (CT) analysis for predicting the pathological response and survival of patients with ESCC who received trimodality therapy.

METHODS

A total of 119 patients with cT3 or T4 ESCC who underwent surgery following NCRT between 2007 and 2019 were assessed. The CT-based parameters were measured with enhanced CT preoperatively, prior to and during treatment. Associations between these parameters and the pathologic response, as well as the prognosis, were examined.

RESULTS

Pretreatment maximum CT value (p = 0.009), pretreatment mean CT value (p = 0.022), preoperative whole tumor volume (WTV, p = 0.003), preoperative largest cross section (LCS, p = 0.002), ΔLCS (pretreatment to preoperative, p = 0.004), ΔWTV (pretreatment to preoperative, p = 0.012), and Δmean CT value (pretreatment to preoperative, p = 0.012) of the primary lesion were significantly associated with a good pathological response. A Cox-regression analysis of recurrence-free survival (RFS) and overall survival (OS) showed that preoperative LCS was an independent CT-based predictor. RFS and OS were significantly higher at the optimal cut-off value of the preoperative LCS (p = 0.036 and p = 0.016, respectively).

CONCLUSIONS

CT-based parameters are thus considered to be valuable predictors of the tumor response and survival after trimodality therapy for ESCC.

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.

Change in Maximal Esophageal Wall Thickness Provides Prediction of Survival and Recurrence in Patients with Esophageal Squamous Cell Carcinoma After Neoadjuvant Chemoradiotherapy and Surgery

Purpose

This study aimed to evaluate the relationship of the percentage decrease of maximal esophageal wall thickness with pathological complete response (pCR) and recurrence in esophageal squamous cell carcinoma (ESCC).

Patients and Methods

A total of 146 ESCC patients treated with neoadjuvant chemoradiotherapy (NCRT) and surgery were included. The prognostic factors for overall survival (OS) and disease-free survival (DFS) were analyzed. The recurrence site, time, and frequency were included in the analysis. The percentage decrease of maximal esophageal wall thickness after NCRT was determined with the formula: [(pre-post)/pre] × 100.

Results

Overall, only 42 patients achieved pCR. Multivariable logistic analyses showed that the percentage decrease of maximal esophageal wall thickness (HR: 2.504; 95% CI: 1.112–5.638, P=0.027) was independently correlated with pCR. In multivariable Cox analyses, a ≤40% percentage decrease of maximal esophageal wall thickness was an independent adverse factor for both OS (HR: 1.907, 95% CI: 1.149–3.165; P=0.012) and DFS (HR: 2.054, 95% CI: 1.288–3.277; P=0.003). Compared with patients with a ≤40% percentage decrease, those with a >40% percentage decrease had better 5-year OS (29.0% vs 60.1%, P<0.05) and DFS (27.8% vs 54.4%, P<0.05). Perineural invasion (PNI) was also an unfavorable factor for OS (HR: 2.138, 95% CI: 0.094–4.178; P=0.026). Lymph vessel invasion (HR: 2.874, 95% CI: 1.574–5.248; P=0.001) and PNI (HR: 2.050; 95% CI: 1.044–4.023; P=0.037) were independent prognosticators for DFS. The rates of local and distant recurrence were also significantly difference between those with a percentage decrease of ≤40% and of >40% (P<0.05).

Conclusion

The percentage decrease of maximal esophageal wall thickness is associated with pCR and recurrence in ESCC patients who undergo NCRT and surgery and can thus be used to independently predict prognosis.

Utility of positron emission-computed tomography for predicting pathological response in resectable oesophageal squamous cell carcinoma after neoadjuvant chemoradiation

OBJECTIVES

For patients with locally advanced oesophageal cancer, improved complete pathological response after neoadjuvant chemoradiation (nCRT) and the detrimental effects on the quality of life related to oesophagectomy have led to the need for a reliable method to select patients who have achieved complete pathological response and do not need surgery. The reliability of 18F-fluorodeoxyglucose positron emission-computed tomography (PET-CT) for predicting the pathological response after nCRT was evaluated.

METHODS

Patients with locally advanced oesophageal cancer who were treated with nCRT and oesophagectomy from July 2010 to February 2017 were analysed. On the post-nCRT PET-CT, a complete metabolic response was defined as all tumourous lesions demonstrating maximum standardized uptake value (SUVmax) ≤2.5. To minimize the effect of radiation-induced oesophagitis, complete metabolic response was also defined as no viable lesion distinguishable from the background with diffuse uptake. The sensitivity, specificity, positive predictive value and negative predictive value were analysed for SUVmax, [X]ΔSUVmax and %ΔSUVmax.

RESULTS

A total of 158 patients with oesophageal squamous cell carcinoma were analysed. The rate of complete pathological response was 27.8%, and that of complete metabolic response was 7.6%. The sensitivity, specificity, positive predictive value and negative predictive value based on SUVmax ≤2.5 and visual normalization were 95%, 14%, 74% and 50%, respectively. Analysis for [X]ΔSUVmax and %ΔSUVmax using the optimal cut-off values determined by the receiver operating characteristic curves did not show an improved predictive efficacy.

CONCLUSIONS

PET-CT is not a reliable tool for predicting pathological response. Patients diagnosed with resectable oesophageal cancer who underwent neoadjuvant therapy should not be exempt from surgery based on PET-CT results.

Assessment of Intratumoral and Peritumoral Computed Tomography Radiomics for Predicting Pathological Complete Response to Neoadjuvant Chemoradiation in Patients With Esophageal Squamous Cell Carcinoma

IMPORTANCE

For patients with locally advanced esophageal squamous cell carcinoma, neoadjuvant chemoradiation has been shown to improve long-term outcomes, but the treatment response varies among patients. Accurate pretreatment prediction of response remains an urgent need.

OBJECTIVE

To determine whether peritumoral radiomics features derived from baseline computed tomography images could provide valuable information about neoadjuvant chemoradiation response and enhance the ability of intratumoral radiomics to estimate pathological complete response.

DESIGN, SETTING, AND PARTICIPANTS

A total of 231 patients with esophageal squamous cell carcinoma, who underwent baseline contrast-enhanced computed tomography and received neoadjuvant chemoradiation followed by surgery at 2 institutions in China, were consecutively included. This diagnostic study used single-institution data between April 2007 and December 2018 to extract radiomics features from intratumoral and peritumoral regions and established intratumoral, peritumoral, and combined radiomics models using different classifiers. External validation was conducted using independent data collected from another hospital during the same period. Radiogenomics analysis using gene expression profile was done in a subgroup of the training set for pathophysiological explanation. Data were analyzed from June to December 2019.

EXPOSURES

Computed tomography-based radiomics.

MAIN OUTCOMES AND MEASURES

The discriminative performances of radiomics models were measured by area under the receiver operating characteristic curve.

RESULTS

Among the 231 patients included (192 men [83.1%]; mean [SD] age, 59.8 [8.7] years), the optimal intratumoral and peritumoral radiomics models yielded similar areas under the receiver operating characteristic curve of 0.730 (95% CI, 0.609-0.850) and 0.734 (0.613-0.854), respectively. The combined model was composed of 7 intratumoral and 6 peritumoral features and achieved better discriminative performance, with an area under the receiver operating characteristic curve of 0.852 (95% CI, 0.753-0.951), accuracy of 84.3%, sensitivity of 90.3%, and specificity of 79.5% in the test set. Gene sets associated with the combined model mainly involved lymphocyte-mediated immunity. The association of peritumoral area with response identification might be partially attributed to type I interferon-related biological process.

CONCLUSIONS AND RELEVANCE

A combination of peritumoral radiomics features appears to improve the predictive performance of intratumoral radiomics to estimate pathological complete response after neoadjuvant chemoradiation in patients with esophageal squamous cell carcinoma. This study underlines the significant application of peritumoral radiomics to assess treatment response in clinical practice.

Total Lesion Glycolysis Assessment Identifies a Patient Fraction With a High Cure Rate Among Esophageal Adenocarcinoma Patients Treated With Definitive Chemoradiation

OBJECTIVE

We aimed to determine whether tumor metabolism could be prognostic of cure in L-EAC patients who receive definitive chemoradiation.

SUMMARY BACKGROUND DATA

Patients with inoperable localized esophageal adenocarcinoma (L-EAC) often receive definitive chemoradiation; however, biomarkers and/or imaging variables to prognosticate cure are missing.

METHODS

Two hundred sixty-six patients with L-EAC who had chemoradiation but not surgery were analyzed from the prospectively maintained EAC databases in the Department of Gastrointestinal Medical Oncology at The University of Texas MD Anderson Cancer Center (Texas, USA) between March 2002 and April 2015. Maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) from the positron emission tomography data were evaluated.

RESULTS

Of 266 patients, 253 (95%) were men; the median age was 67 years (range 20-91 yrs) and 153 had poorly differentiated L-EAC. The median SUVmax was 10.3 (range 0-87) and the median TLG was 85.7 (range 0-3227). Both SUVmax and TLG were higher among those with: tumors >5 cm in length, high clinical stage, and high tumor and node categories by TNM staging (all P < 0.0001). Of 234 patients evaluable for cure, 60 (25.6%) achieved cure. In the multivariable logistic regression model, low TLG (but not low SUVmax) was associated with cure (continuous TLG value: odds ratio 0.70, 95% confidence interval (CI) 0.54-0.92). TLG was quantified into 4 quartile categorical variables; first quartile (Q1; <32), second quartile (Q2; 32.0-85.6), third quartile (Q3; 85.6-228.4), and fourth quartile (Q4; >228.4); the cure rate was only 10.3% in Q4 and 5.1% in Q3 but increased to 28.8% in Q2, and 58.6% in Q1. The cross-validation resulted in an average accuracy of prediction score of 0.81 (95% CI, 0.75-0.86).

CONCLUSIONS

In this cross-validated model, 59% of patients in the 1st quartile were cured following definitive chemoradiation. Baseline TLG could be pursued as one of the tools for esophageal preservation.

Benefits of positron emission tomography scans for the evaluation of radiotherapy

The assessment of tumour response during and after radiotherapy determines the subsequent management of patients (adaptation of treatment plan, monitoring, adjuvant treatment, rescue treatment or palliative care). In addition to its role in extension assessment and therapeutic planning, positron emission tomography combined with computed tomography provides useful functional information for the evaluation of tumour response. The objective of this article is to review published data on positron emission tomography combined with computed tomography as a tool for evaluating external radiotherapy for cancers. Data on positron emission tomography combined with computed tomography scans acquired at different times (during, after initial and after definitive [chemo-]radiotherapy, during post-treatment follow-up) in solid tumours (lung, head and neck, cervix, oesophagus, prostate and rectum) were collected and analysed. Recent recommendations of the National Comprehensive Cancer Network are also reported. Positron emission tomography combined with computed tomography with (¹⁸F)-labelled fluorodeoxyglucose has a well-established role in clinical routine after chemoradiotherapy for locally advanced head and neck cancers, particularly to limit the number of neck lymph node dissection. This imaging modality also has a place for the evaluation of initial chemoradiotherapy of oesophageal cancer, including the detection of distant metastases, and for the post-therapeutic evaluation of cervical cancer. Several radiotracers for positron emission tomography combined with computed tomography, such as choline, are also recommended for patients with prostate cancer with biochemical failure. (¹⁸F)-fluorodeoxyglucose positron emission tomography combined with computed tomography is optional in many other circumstances and its clinical benefits, possibly in combination with MRI, to assess response to radiotherapy remain a very active area of research.

Selecting esophageal cancer patients for lymphadenectomy after neoadjuvant chemoradiotherapy: a modeling study

OBJECTIVES

Two-thirds of patients do not harbor lymph node (LN) metastases after neoadjuvant chemoradiotherapy (nCRT). Our aim was to explore under which circumstances a selective lymph node dissection (LND) strategy, which selects patients for LND based on the restaging results after nCRT, has added value compared with standard LND in esophageal cancer.

DESIGN

A decision tree with state-transition model was developed. Input data on short-term and long-term consequences were derived from literature. Sensitivity analyses were conducted to assess promising scenarios and uncertainty.

SETTING

Dutch healthcare system.

PARTICIPANTS

Hypothetical cohort of esophageal cancer patients who have already received nCRT and are scheduled for esophagectomy.

INTERVENTIONS

A standard LND cohort was compared with a cohort of patients that received selective LND based on the restaging results after nCRT.

MAIN OUTCOME MEASURES

Quality-adjusted life years (QALYs), residual LN metastases and LND-related complications.

RESULTS

Selective LND could have short-term benefits, that is, a decrease in the number of performed LNDs and LND-related complications. However, this may not outweigh a slight increase in residual LN metastases which negatively impacts QALYs in the long-term. To accomplish equal QALYs as with standard LND, a new surgical strategy should have the same or higher treatment success rate as standard LND, that is, should show equal or less recurrences due to residual LN metastases.

CONCLUSIONS

The reduction in LND-related complications that is accomplished by selecting patients for LND based on restaging results after nCRT seems not to outweigh a QALY loss in the long-term due to residual LN metastases. Despite the short-term advantages of selective LND, this strategy can only match long-term QALYs of standard LND when its success rate equals the success rate of standard LND.

Accuracy of Detecting Residual Disease After Neoadjuvant Chemoradiotherapy for Esophageal Cancer: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of this study was to perform a meta-analysis on the accuracy of endoscopic biopsies, EUS, and 18F-FDG PET(-CT) for detecting residual disease after neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer.

SUMMARY OF BACKGROUND DATA

After nCRT, one-third of patients have a pathologically complete response in the resection specimen. Before an active surveillance strategy could be offered to these patients, clinically complete responders should be accurately identified.

METHODS

Embase, Medline, Cochrane, and Web-of-Science were searched until February 2018 for studies on accuracy of endoscopic biopsies, EUS, or PET(-CT) for detecting locoregional residual disease after nCRT for squamous cell- or adenocarcinoma. Pooled sensitivities and specificities were calculated using random-effect meta-analyses.

RESULTS

Forty-four studies were included for meta-analyses. For detecting residual disease at the primary tumor site, 12 studies evaluated endoscopic biopsies, 11 qualitative EUS, 14 qualitative PET, 8 quantitative PET using maximum standardized uptake value (SUVmax), and 7 quantitative PET using percentage reduction of SUVmax (%ΔSUVmax). Pooled sensitivities and specificities were 33% and 95% for endoscopic biopsies, 96% and 8% for qualitative EUS, 74% and 52% for qualitative PET, 69% and 72% for PET-SUVmax, and 73% and 63% for PET-%ΔSUVmax. For detecting residual nodal disease, 11 studies evaluated qualitative EUS with a pooled sensitivity and specificity of 68% and 57%, respectively. In subgroup analyses, sensitivity of PET-%ΔSUVmax and EUS for nodal disease was higher in squamous cell carcinoma than adenocarcinoma.

CONCLUSIONS

Current literature suggests insufficient accuracy of endoscopic biopsies, EUS, and 18F-FDG PET(-CT) as single modalities for detecting residual disease after nCRT for esophageal cancer.

Extent and consequences of lymphadenectomy in oesophageal cancer surgery: case vignette survey

Objectives

Lymph node dissection (LND) is part of the standard operating procedure in patients with resectable oesophageal cancer after neoadjuvant chemoradiotherapy regardless of lymph node (LN) status. The aims of this case vignette survey were to acquire expert opinions on the current practice of LND and to determine potential consequences of non-invasive LN staging on the extent of LND and postoperative morbidity.

Design

An online survey including five short clinical cases (case vignettes) was sent to 272 oesophageal surgeons worldwide.

Participants

86 oesophageal surgeons (median experience in oesophageal surgery of 15 years) participated in the survey (response rate 32%).

Main outcome measures

Extent of standard LND, potential changes in LND based on accurate LN staging and consequences for postoperative morbidity were evaluated.

Results

Standard LND varied considerably between experts; for example, pulmonary ligament, splenic artery, aortopulmonary window and paratracheal LNs are routinely dissected in less than 60%. The omission of (parts of) LND is expected to decrease the number of chyle leakages, pneumonias, and laryngeal nerve pareses and to reduce operating time. In order to guide surgical treatment decisions, a diagnostic test for LN staging after neoadjuvant therapy requires a minimum sensitivity of 92% and a specificity of 90%.

Conclusions

This expert case vignette survey study shows that there is no consensus on the extent of standard LND. Oesophageal surgeons seem more willing to extend LND rather than omit LND, based on accurate LN staging. The majority of surgeons expect that less extensive LND can reduce postoperative morbidity.

Added value of MRI to endoscopic and endosonographic response assessment after neoadjuvant chemoradiotherapy in oesophageal cancer

OBJECTIVES

In order to select oesophageal cancer patients after neoadjuvant chemoradiotherapy (nCRT) for organ-preserving treatment instead of surgery, a high diagnostic accuracy is required. The aim of this study was to evaluate whether MRI had additional value to gastroscopy with biopsies and endosonographic ultrasound (EUS) with fine needle aspiration (FNA) for the detection of residual tumour after nCRT.

METHODS

Twenty-two patients with oesophageal cancer eligible for nCRT followed by oesophagectomy were prospectively included. All patients underwent (T2- and diffusion-weighted) MRI and gastroscopy+EUS before and after nCRT. Histopathology after oesophagectomy was the reference standard with pathological complete response (pCR) defined as ypT0N0. Diagnostic performance regarding the detection of residual tumour was calculated for gastroscopic biopsies and for EUS-FNA without and with MRI.

RESULTS

Nineteen of the 22 patients (86%) did not achieve pCR after nCRT (7 ypT+N+, 11 ypT+N0, 1 ypT0N+). Biopsies detected residual tumour in 6 of 18 ypT+ patients. After adding MRI, 16 of 18 residual tumours were assessed correctly. EUS-FNA detected 3 out of 8 ypN+ patients, while MRI did not improve detection. Overall, adding MRI improved sensitivity for detection of residual tumour to 89% (17 of 19) from 47% (9 of 19) with endoscopic biopsies and EUS-FNA only.

CONCLUSION

In this small study, the detection of residual tumour after nCRT in oesophageal cancer patients was improved by the addition of MRI to gastroscopy and EUS.

KEY POINTS

• In this small study, the detection of residual tumour after neoadjuvant chemoradiotherapy in oesophageal cancer patients was improved by adding MRI including diffusion-weighted images to gastroscopy and endosonographic ultrasound. • With the addition of MRI assessment to gastroscopy and endosonographic ultrasound, the considerable risk of missing residual tumours decreased from 53 to 11%, while the pitfall was overstaging in one out of three complete responders.

Clinical significance of evaluating endoscopic response to neoadjuvant chemotherapy in esophageal squamous cell carcinoma

BACKGROUND AND AIM

Clinical significance of endoscopic response (ER) after neoadjuvant chemotherapy (NAC) for esophageal cancer has not been fully understood. Thus, the present study aimed to investigate the association between ER to NAC and its clinicopathological outcomes in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

In total, 141 patients who underwent NAC and subsequent esophagectomy for ESCC were included. ER to NAC was retrospectively evaluated based on macroscopic findings of the primary tumor, which was classified into three categories: endoscopic no response (eNR), endoscopic partial response (ePR), and endoscopic good response (eGR). An endoscopic responder was defined as patients with eGR/ePR.

RESULTS

Approximately 89.4% of patients had cStage II-III disease, and 7.1% had pathological complete response. Upon ER evaluation, eNR, ePR, and eGR were observed in 46 (32.6%), 54 (38.3%), and 41 (29.1%) patients, respectively. Pathological responders significantly increased as the ER grade became better. Among preoperative clinical factors, only ER significantly correlated with pathological response in univariate and multivariate analysis. Endoscopic responders showed a significantly better prognosis than did eNR patients (P < 0.001), although the overall survival (OS) of the patients with eGR and ePR was equivalent. Endoscopic responder, ypT, ypN, and pathological responder were significant predictors of OS in the univariate analysis, and endoscopic responder, ypN, and pathological responder were independent predictors in the multivariate analysis.

CONCLUSION

This study suggests that ER can be a simple and important tool to predict the pathological response and survival of patients who undergo NAC for ESCC.

The value of GRASP on DCE-MRI for assessing response to neoadjuvant chemotherapy in patients with esophageal cancer

Background

To compare the value of two dynamic contrast-enhanced Magnetic Resonance Images (DCE-MRI) reconstruction approaches, namely golden-angle radial sparse parallel (GRASP) and view-sharing with golden-angle radial profile (VS-GR) reconstruction, and evaluate their values in assessing response to neoadjuvant chemotherapy (nCT) in patients with esophageal cancer (EC).

Methods

EC patients receiving nCT before surgery were enrolled prospectively. DCE-MRI scanning was performed after nCT and within 1 week before surgery. Tumor Regression Grade (TRG) was used for chemotherapy response evaluation, and patients were stratified into a responsive group (TRG1 + 2) and a non-responsive group (TRG3 + 4 + 5). Wilcoxon test was utilized for comparing GRASP and VS-GR reconstruction, Kruskal-Wallis and Mann-Whitney test was performed for each parameter to assess response, and Spearman test was performed for analyzing correlation between parameters and TRGs, as well as responder and non-responder. The receiver operating characteristic (ROC) was utilized for each significant parameter to assess its accuracy between responders and non-responders.

Results

Among the 64 patients included in this cohort (52 male, 12 female; average age of 59.1 ± 7.9 years), 4 patients showed TRG1, 4 patients were TRG2, 7 patients were TRG3, 11 patients were TRG4, and 38 patients were TRG5. They were stratified into 8 responders and 56 non-responders.

A total of 15 parameters were calculated from each tumor. With VS-GR, 10/15 parameters significantly correlated with TRG and response groups. Of these, only AUCmax showed moderate correlation with TRG, 7 showed low correlation and 2 showed negligible correlation with TRG. 8 showed low correlation and 2 showed negligible correlation with response groups. With GRASP, 13/15 parameters significantly correlated with TRG and response groups. Of these, 10 showed low correlation and 3 showed negligible correlation with TRG. 11 showed low correlation and 2 showed negligible correlation with TRG. Seven parameters (AUC^* > 0.70, P < 0.05) showed good performance in response groups.

Conclusions

In patients with esophageal cancer on neoadjuvant chemotherapy, several parameters can differentiate responders from non-responders, using both GRASP and VS-GR techniques. GRASP may be able to better differentiate these two groups compared to VS-GR.

Trial registration for this prospective study: ChiCTR, ChiCTR-DOD-14005308. Registered 2 October 2014.

Detecting Pathological Complete Response in Esophageal Cancer after Neoadjuvant Therapy Based on Imaging Techniques: A Diagnostic Systematic Review and Meta-Analysis

INTRODUCTION

Up to 32% of patients with esophageal cancer show a pathological complete response (ypCR) after neoadjuvant therapy. To prevent overtreatment, the indication to perform esophagectomy in these patients should be reconsidered. Implementing an organ-preserving strategy for patients with ypCR requires an accurate assessment of residual disease after neoadjuvant treatment. The aim of this study was to systematically review the effectiveness of imaging techniques used for detection of ypCR after neoadjuvant therapy but before resection in patients with esophageal cancer.

METHODS

A systematic literature search of the Medline, Embase, and Cochrane Library databases was performed from January 1, 2000, to December 13, 2017. Eligible studies were diagnostic studies that compared results of imaging modalities after neoadjuvant therapy to histopathological findings in the resection specimen after esophagectomy. Methodological quality was assessed by the Cochrane Quality Assessment of Diagnostic Accuracy Studies, version 2, model. Primary outcome measures were true positive, false-positive, false-negative, and true negative values of imaging techniques predicting ypCR. A meta-analysis was performed by pooling sensitivities and specificities by using a bivariate model.

RESULTS

A total of 4420 articles were identified. After exclusion of irrelevant titles and abstracts, 360 articles were reviewed in full text. In total, four imaging modalities (computed tomography [CT], positron emission tomography [PET-CT], endoscopic ultrasound [EUS], and magnetic resonance imaging [MRI]) were used for restaging. The meta-analysis was conducted with data from 56 studies involving 3625 patients. The pooled sensitivities of CT, PET-CT, EUS, and MRI for detecting ypCR were 0.35, 0.62, 0.01 and 0.80, respectively, whereas the pooled specificities were 0.83, 0.73, 0.99, and 0.83, respectively. The positive predictive value in detecting ypCR was 0.47 for CT, 0.41 for PET-CT, not applicable for EUS, and 0.61 for MRI.

CONCLUSION

Current imaging modalities such as CT, PET-CT, and EUS seem to be insufficiently accurate to identify complete responders. More accurate diagnostic tests are needed to improve restaging accuracy for patients with esophageal cancer.

Tumor Remission and Tumor-Infiltrating Lymphocytes During Chemoradiation Therapy: Predictive and Prognostic Markers in Locally Advanced Esophageal Squamous Cell Carcinoma

PURPOSE

Clinical tools are unavailable for accurate prediction of pathologic responses to chemoradiation therapy (CRT) among patients with esophageal squamous cell carcinoma (ESCC) before surgery. We evaluated tumor remission and tumor-infiltrating lymphocytes (TILs) during CRT as predictors of pathologic response and prognostic markers for patients with locally advanced ESCC treated with neoadjuvant CRT (neo-CRT) or definitive CRT.

METHODS AND MATERIALS

We analyzed patients with locally advanced ESCC (N = 164) who underwent neo-CRT (N = 48) or definitive CRT (N = 116). Patients underwent endoscopic ultrasonography and biopsies when induction CRT finished. Tumor remission characteristics were designated minor (-/+) to excellent remission (ER) (+++). TILs were determined in 10% increments. Tumor remission, TILs, or both were associated with pathologic complete response (pCR) and survival in the neo-CRT group and then analyzed in the definitive CRT group.

RESULTS

ER and lymphocyte-predominant ESCC (LPE; ≥60% TILs) were identified according to the pCR rate and disease-free survival. We built a prediction model for pCR incorporating ER and LPE. The area under the receiver operating characteristic curve was 0.877, and sensitivity and specificity were 86.7% and 90.9%, respectively. Furthermore, this model identified pathologic response with an excellent calibration. Disease-free survival of patients with ER and LPE tumors was significantly longer than that of other patients.

CONCLUSIONS

When we included tumor remission and TILs during CRT, our model predicted pCR with high probability and helped stratify prognostic subgroups, thereby guiding future therapy decisions for patients with locally advanced ESCC. Validation of this model in larger, prospective, multicenter studies is essential.

Accuracy of 18F-FDG PET/CT in Predicting Residual Disease After Neoadjuvant Chemoradiotherapy for Esophageal Cancer

Our purpose was to prospectively investigate optimal evaluation of qualitative and quantitative ¹⁸F-FDG PET/CT in response evaluations 12-14 wk after neoadjuvant chemoradiotherapy (nCRT) in esophageal cancer patients. Methods: This was a side study of the prospective diagnostic pre-SANO trial. ¹⁸F-FDG PET/CT scans at baseline and at 12-14 wk after nCRT were qualitatively assessed for the presence of tumor. Maximum SUVs normalized for lean body mass (SUL_max) were measured in all scans. The primary endpoint was the proportion of false-negative patients with tumor regression grade (TRG) 3-4 (>10% vital residual tumor) in qualitative and quantitative analyses. Receiver-operating-characteristic curve analysis for TRG1 versus TRG3-4 using SUL_max, SUL_max tumor-to-esophagus ratio, and Δ%SUL_max was performed to define optimal cutoffs. Secondary endpoints were sensitivity, specificity, negative predictive value, and positive predictive value for TRG1 versus TRG2-4. Results: In total, 129 of 219 patients were analyzed. Qualitative ¹⁸F-FDG PET/CT was unable to detect TRG3-4 in 15% of patients. Sensitivity, specificity, negative predictive value, and positive predictive value in qualitative analysis for detecting TRG1 versus TRG2-4 was 80%, 37%, 42%, and 77%, respectively. In 18 of 190 patients (10%) with follow-up scans after nCRT, ¹⁸F-FDG PET/CT identified new interval metastases. Quantitative parameters did not detect TRG3-4 tumor in 27%-61% of patients. The optimal cutoff for detecting TRG1 versus TRG2-4 was a post-nCRT SUL_max of 2.93 (area under receiver-operating-characteristic curve, 0.70). Conclusion: Qualitative and quantitative analyses of ¹⁸F-FDG PET/CT are unable to accurately detect TRG3-4 and to discriminate substantial residual disease from benign inflammation-induced ¹⁸F-FDG uptake after nCRT. However, ¹⁸F-FDG PET/CT is useful for the detection of interval metastases and might become useful in an active surveillance strategy with serial ¹⁸F-FDG PET/CT scanning.

Diagnostic performance of MRI for assessment of response to neoadjuvant chemoradiotherapy in oesophageal cancer

Background

Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non‐surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2‐weighted (T2W) and diffusion‐weighted (DW) MRI.

Methods

Patients with locally advanced oesophageal cancer who underwent T2W‐ and DW‐MRI (1·5 T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five‐point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW‐MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated.

Results

Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W‐MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W + DW‐MRI were 90–97 and 42–50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W‐MRI, and 0·71, 0·70 and 0·70 on T2W + DW‐MRI (P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively). The κ value for interobserver agreement improved from 0·24–0·55 on T2W‐MRI to 0·55–0·71 with DW‐MRI.

Conclusion

Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.

A Diagnostic Algorithm That Combines Quantitative 18F-FDG PET Parameters and Contrast-Enhanced CT Improves Posttherapeutic Locoregional Restaging and Prognostication of Survival in Patients With Esophageal Cancer

PURPOSE

The aim of this study was to determine whether the combination of contrast-enhanced CT (CE-CT) and quantitative F-FDG PET parameters improves locoregional restaging in esophageal cancer (EC) after neoadjuvant therapy.

METHODS

Eighty-eight consecutive patients with locally advanced esophageal cancer, who underwent restaging after neoadjuvant chemotherapy or chemoradiotherapy before esophagectomy, were included in this retrospective study. The diagnostic accuracy of CE-CT, visual F-FDG PET/CT (vPET/CT), and quantitative PET parameters was assessed for T and N staging. Histopathology was used as the reference standard. The prognostic value for recurrence-free survival, cancer-specific survival, and overall survival was assessed using Cox regression analysis.

RESULTS

Sensitivity, positive predictive value, and accuracy were 78.8%, 70.2%, and 59.0% (CE-CT), and 81.1%, 81.1%, and 68.2% (vPET/CT) for T staging as well as 59.5%, 75.9%, and 50.0% (CE-CT), and 70.2%, 93.7%, and 67.0% (vPET/CT) for N staging, respectively. Tumor length and metabolic tumor volume (MTV) exhibited an incremental increase with advancing T stages (P = 0.002 and 0.038). Contrast-enhanced CT had the highest sensitivity to differentiate advanced T stages (T3/4 vs 0-2; area under the receiver operating curve [AUC], 0.86; P < 0.001), whereas MTV at a threshold of 5.8 mL had the highest sensitivity to detect complete response (T0 vs 1-4; AUC, 0.77; P = 0.002). Contrast-enhanced CT and MTV combined had an even superior accuracy to predict complete response (AUC, 0.82; P < 0.001). The imaging American Joint Committee on Cancer stage provided a better prognostication of recurrence-free survival, cancer-specific survival, and overall survival than either T stage, N stage derived from CE-CT or vPET/CT, or quantitative PET parameters alone.

CONCLUSIONS

Combined CE-CT and MTV had the highest diagnostic accuracy to identify the posttherapeutic T stage, allowing for robust prediction of recurrence and survival.

Novel imaging techniques in staging oesophageal cancer

The survival of oesophageal cancer is poor as most patients present with advanced disease. Radiological staging of oesophageal cancer is complex but is fundamental to clinical management. Accurate staging investigations are vitally important to guide treatment decisions and optimise patient outcomes. A combination of baseline computed tomography (CT), endoscopic ultrasound (EUS) and positron emission tomography (PET) are currently used for initial treatment decisions. The potential value of these imaging modalities to re-stage disease, monitor response and alter treatment is currently being investigated. This review presents an essential update on the accuracy of oesophageal cancer staging investigations, their use in re-staging after neo-adjuvant therapy and introduces evolving imaging techniques, including novel biomarkers that have clinical potential in oesophageal cancer.

Clinical predictors of pathologically response after neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma: long term outcomes of a phase II study

Background

A pathologically complete response (pCR) or near pCR to neoadjuvant chemoradiotherapy (NCRT) might imply a better prognosis in patients with esophageal cancer. The aim of the study is to identify clinical factors associated with a pCR or near pCR.

Methods

We retrospectively analyzed 40 patients with radical esophagectomy after NCRT for esophageal squamous cell carcinoma (ESCC) from January 2001 to December 2006 in Sun Yat-sen University Cancer Center. Clinical factors included age, gender, weight loss, dysphagia, drinking status, smoking status, tumor location, tumor length, tumor grade, cT status, cN status, the regimen of chemotherapy and the interval between NCRT and surgery as potential predictors for a pCR or near pCR. Logistic regression was used to estimate the independent factors for a pCR or near pCR.

Results

After surgical resection, 22.5% of the patients obtained the pCR. Patients with pCR had a better prognosis than those with non-pCR. However, there was no statistically significantly difference between the two groups (P=0.124). We separated the patients into pCR or near pCR (good responders, GRs) and poor responders (PR) based on the histology. GR showed better overall survival (OS) than PR (P=0.014). Univariate analysis indicated that short tumor length, good tumor grade and never drinking were associated with GR to NCRT. Using logistic regression analysis, good tumor grade was the only independent factor for the GR to NCRT (P=0.021). Cox regression revealed that weight loss, drinking status and GR were independent factors in ESCC patients with radical esophagectomy after NCRT.

Conclusions

Our study indicated that good tumor grade were an independent significant factor for the GR to NCRT. Weight loss, drinking status and GR were independent factors in patients with radical esophagectomy after NCRT. GR may improve OS of ESCC patients receiving NCRT.

Timing of esophagectomy after neoadjuvant chemoradiation treatment in squamous cell carcinoma

BACKGROUND

Time interval between neoadjuvant (combined) chemotherapy and radiation (nCRT) and surgery has been linked to pathologic response rates and outcomes in patients with various solid cancers. The optimal timing between nCRT and esophagectomy in patients with esophageal squamous cell carcinoma (SCC), however, is not known. Our aim was to analyze the relation between elapsed time from completion of nCRT to esophagectomy and postsurgical mortality and overall survival.

METHODS

We reviewed the National Cancer Database for patients with SCC (n = 1,244) of the esophagus diagnosed between 2003 and 2011 who were treated with nCRT followed by esophagectomy within 26 weeks after completion of nCRT.

RESULTS

Thirty-day mortality was 5.6% and 90-day mortality was 11.1%. The duration of post-nCRT interval was not a predictor of 30-day and 90-day postoperative mortality in multivariate models, but 30-day postoperative mortality was predictable based on increasing Charlson-Deyo comorbidities (adjusted odds ratio [aOR] 1.77, P = .054) and improved in academic institutions (aOR 0.66, P = .005). Similar findings were found for 90-day mortality (comorbidity index aOR 1.58, P = .046) and for treatment at an academic facility (0.82, P = .062). In a multivariate survival analysis, the duration of the post-nCRT interval was not found to be a predictor of overall survival (P = .769), whereas increasing age (hazard ratio [HR] 1.02, P = .005), increasing comorbidity score (HR 1.38, P = .005), treatment at an academic hospital (HR 0.84, P = .001), and post-treatment nodal status (HR 1.73, P < .001) were predictors.

CONCLUSION

Perioperative mortality and overall survival are not affected by the time interval between completion of nCRT and esophagectomy among patients with SCC histology.

Detection of residual disease after neoadjuvant chemoradiotherapy for oesophageal cancer (preSANO): a prospective multicentre, diagnostic cohort study

BACKGROUND

After neoadjuvant chemoradiotherapy for oesophageal cancer, roughly half of the patients with squamous cell carcinoma and a quarter of those with adenocarcinoma have a pathological complete response of the primary tumour before surgery. Thus, the necessity of standard oesophagectomy after neoadjuvant chemoradiotherapy should be reconsidered for patients who respond sufficiently to neoadjuvant treatment. In this study, we aimed to establish the accuracy of detection of residual disease after neoadjuvant chemoradiotherapy with different diagnostic approaches, and the optimal combination of diagnostic techniques for clinical response evaluations.

METHODS

The preSANO trial was a prospective, multicentre, diagnostic cohort study at six centres in the Netherlands. Eligible patients were aged 18 years or older, had histologically proven, resectable, squamous cell carcinoma or adenocarcinoma of the oesophagus or oesophagogastric junction, and were eligible for potential curative therapy with neoadjuvant chemoradiotherapy (five weekly cycles of carboplatin [area under the curve 2 mg/mL per min] plus paclitaxel [50 mg/m² of body-surface area] combined with 41·4 Gy radiotherapy in 23 fractions) followed by oesophagectomy. 4-6 weeks after completion of neoadjuvant chemoradiotherapy, patients had oesophagogastroduodenoscopy with biopsies and endoscopic ultrasonography with measurement of maximum tumour thickness. Patients with histologically proven locoregional residual disease or no-pass during endoscopy and without distant metastases underwent immediate surgical resection. In the remaining patients a second clinical response evaluation was done (PET-CT, oesophagogastroduodenoscopy with biopsies, endoscopic ultrasonography with measurement of maximum tumour thickness, and fine-needle aspiration of suspicious lymph nodes), followed by surgery 12-14 weeks after completion of neoadjuvant chemoradiotherapy. The primary endpoint was the correlation between clinical response during clinical response evaluations and the final pathological response in resection specimens, as shown by the proportion of tumour regression grade (TRG) 3 or 4 (>10% residual carcinoma in the resection specimen) residual tumours that was missed during clinical response evaluations. This study was registered with the Netherlands Trial Register (NTR4834), and has been completed.

FINDINGS

Between July 22, 2013, and Dec 28, 2016, 219 patients were included, 207 of whom were included in the analyses. Eight of 26 TRG3 or TRG4 tumours (31% [95% CI 17-50]) were missed by endoscopy with regular biopsies and fine-needle aspiration. Four of 41 TRG3 or TRG4 tumours (10% [95% CI 4-23]) were missed with bite-on-bite biopsies and fine-needle aspiration. Endoscopic ultrasonography with maximum tumour thickness measurement missed TRG3 or TRG4 residual tumours in 11 of 39 patients (28% [95% CI 17-44]). PET-CT missed six of 41 TRG3 or TRG4 tumours (15% [95% CI 7-28]). PET-CT detected interval distant histologically proven metastases in 18 (9%) of 190 patients (one squamous cell carcinoma, 17 adenocarcinomas).

INTERPRETATION

After neoadjuvant chemoradiotherapy for oesophageal cancer, clinical response evaluation with endoscopic ultrasonography, bite-on-bite biopsies, and fine-needle aspiration of suspicious lymph nodes was adequate for detection of locoregional residual disease, with PET-CT for detection of interval metastases. Active surveillance with this combination of diagnostic modalities is now being assessed in a phase 3 randomised controlled trial (SANO trial; Netherlands Trial Register NTR6803).

FUNDING

Dutch Cancer Society.

Preoperative prediction of a pathologic complete response of esophageal squamous cell carcinoma to neoadjuvant chemoradiotherapy

BACKGROUND

The accurate prediction of a pathologic complete response (ypT0N0M [LYM] 0 ypStage 0) before operation is essential for selecting appropriate strategies for treating esophageal cancer after neoadjuvant chemoradiotherapy.

METHODS

We reviewed 130 consecutive patients with esophageal squamous cell carcinoma who were evaluated preoperatively using upper gastrointestinal endoscopy, computed tomography, and 18F-fluorodeoxyglucose-positron emission tomography after neoadjuvant chemoradiotherapy and subsequently underwent esophagectomy. Our aim was to determine the diagnostic abilities of computed tomography, 18F-fluorodeoxyglucose-positron emission tomography, and endoscopy to predict preoperatively a pathologic complete response of the primary site of the locally advanced esophageal squamous cell carcinoma and associated lymph nodes to trimodal neoadjuvant chemoradiotherapy. Associations between clinical complete response (ycT0N0M [LYM] 0 ycStage 0) and pathologic complete response were investigated preoperatively.

RESULTS

Twenty-nine (22.3%) and 43 (33.1%) patients, respectively, achieved clinical complete response and pathologic complete response, which were associated (P=.001). The sensitivity and specificity, as well as the positive and negative predictive values of clinical complete response to define pathologic complete response were 39.5%, 86.2%, 58.6%, and 74.3%, respectively. Univariate and multivariate analyses selected clinical complete response as the sole independent preoperative predictor of pathologic complete response (clinical complete responses versus non-clinical complete responses: odds ratio: 0.26, 95% confidence interval, 0.10-0.65, P=.004). Recurrence-free and overall survival (OS) rates were better in patients with than in those without clinical complete response (5-year recurrence-free and overall survival: 69.0% vs 41.4% and 75.9% vs 45.0%, respectively, both P=.02). Furthermore, clinical complete response was an independent preoperative predictor of recurrence-free survival (clinical complete response versus nonclinical complete response: hazard ratio: 2.20, 95% confidence interval, 1.08-4.45, P=.03).

CONCLUSION

Although pathologic complete response was predictable preoperatively to some extent, the accuracy was somewhat low. Considerable caution should be exercised when selecting the watch-and-wait approach with operation as needed and omitting planned operative intervention even for patients who achieve clinical complete response after neoadjuvant chemoradiotherapy.

Personalized therapy based on image for esophageal or gastroesophageal junction adenocarcinoma

Preoperative therapy is the gold standard for esophageal or gastroesophageal junction adenocarcinoma. Positron emission tomography (PET) is not only essential for tumor staging, but changes in glucose consumption correspond with response to therapy and correlated with prognosis. Therefore, with further refinement, PET parameter can serve as a tool for personalized therapy. For instance, the Municon trials suggested the possibility of PET-response guided therapy for esophageal adenocarcinoma (EAC) patients, however there are limitations. New PET parameters such as total lesion glycolysis (TLG) or magnetic resonance imaging (MRI) may provide better response prediction. Furthermore, PET parameters combined with genomic profiling might enhance better treatment selection, prediction, and prognostication. Here, we summarized the current state of understanding and future possibilities.

Early Metabolic Change after Induction Chemotherapy Predicts Histologic Response and Prognosis in Patients with Esophageal Cancer: Secondary Analysis of a Randomized Trial

BACKGROUND

Early metabolic response after preoperative induction chemotherapy (IC) appears to predict histologic response and prognosis in esophageal cancer (EC), but the usefulness of this approach needs further development.

OBJECTIVE

We evaluated metabolic response after one cycle of IC using positron emission tomography (PET) to correlate PET response and outcomes.

PATIENTS AND METHODS

We retrospectively analyzed PET data from a randomized phase 2 trial (NCT00525915) of chemoradiation and surgery with or without IC for the treatment of EC. PET was performed at baseline, after one cycle of IC, and 5-7 weeks after chemoradiation. The relationship between PET response (≥35% reduction in standardized uptake value [SUV]) after IC and treatment response was analyzed.

RESULTS

In 63 patients who received IC, the mean initial SUVmax prior to treatment was 11.9 ± 8.04 and mean SUVmax after one cycle of IC was 6.47 ± 4.45. The mean SUV reduction after IC was 39.3%. Eleven of 37 PET responders achieved a pathologic complete response (pCR), but only two of 22 PET non-responders did (univariate logistic regression; odds ratio: 4.25, 95% confidence interval: 0.83-21.77; p = 0.08). PET responders to IC had significantly longer overall survival (OS) than PET nonresponders (log-rank p = 0.009). PET response after chemoradiation was not correlated with OS (log-rank p = 0.15).

CONCLUSION

Early PET response after IC is prognostic, but subsequent PET changes (for example, after chemoradiation) are not prognostic. Early PET response might have the potential of predicting pCR.

Management of Patients With Adenocarcinoma or Squamous Cancer of the Esophagus

Esophageal cancer is characterized by early and frequent metastasis. Surgery is the primary treatment for early-stage disease, whereas patients with patients with locally advanced disease receive perioperative chemotherapy or chemoradiotherapy. Squamous cancers can be treated with primary chemoradiotherapy without surgery, depending on their response to therapy and patient tolerance for subsequent surgery. Chemotherapy with a fluorinated pyrimidine and a platinum agent, followed by later treatment with taxanes and irinotecan, provides some benefit. Agents that inhibit the erb-b2 receptor tyrosine kinase 2 (ERBB2 or HER2), or vascular endothelial growth factor, including trastuzumab, ramucirumab, and apatinib, increase response and survival times. Esophageal adenocarcinomas have mutations in tumor protein p53 and mutations that activate receptor-associated tyrosine kinase, vascular endothelial growth factor, and cell cycle pathways, whereas esophageal squamous tumors have a distinct set of mutations. Esophageal cancers develop systems to evade anti-tumor immune responses, but studies are needed to determine how immune checkpoint modification contributes to esophageal tumor development.

Active surveillance in clinically complete responders after neoadjuvant chemoradiotherapy for esophageal or junctional cancer

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is standard of care for locally advanced esophageal cancer in many countries. After nCRT up to one third of all patients have a pathologically complete response in the resection specimen, posing an ethical imperative to reconsider the necessity of standard surgery in all operable patients after nCRT. An active surveillance strategy following nCRT, in which patients are subjected to frequent clinical investigations after the completion of neoadjuvant therapy, has been evaluated in other types of cancer with promising results. In esophageal cancer, both patients who are cured by neoadjuvant therapy alone as well as patients with subclinical disseminated disease at the time of completion of neoadjuvant therapy may benefit from such an organ sparing approach. Active surveillance is currently applied in selected patients with esophageal cancer who refuse surgery or are medically unfit for major surgery after completion of nCRT, but this strategy is not (yet) adopted as an alternative to standard surgery or definitive chemoradiation. The available literature is scarce, but suggests that long-term oncological outcomes after active surveillance are noninferior compared to standard surgical resection, providing justification for comparison of both treatments in a phase III trial. This review gives an overview of the current knowledge regarding active surveillance after completion of nCRT in esophageal cancer and outlines future research perspectives.

Significance of baseline FDG-PET/CT scan as a method of staging regional lymph nodes in patients with operable distal oesophageal or gastroesophageal junction adenocarcinoma

BACKGROUND

The new American Joint Committee on Cancer eighth edition (AJCC8) staging is the first to describe separate clinical and pathology staging systems, but still has low performance to predict prognosis in patients with oesophageal/gastroesophageal junction (O/GOJ) adenocarcinoma, who are candidates for surgery. Recent studies have demonstrated that O/GOJ cancer patients with 18F-fluorodeoxyglucose (FDG) avid regional lymph nodes (RLNs) may have poor prognosis. The aim of our study was to examine whether the baseline assessment of the FDG uptake of RLN improves the prognostic accuracy of the new AJCC8 staging.

PATIENTS AND METHODS

This single-centre retrospective study included patients with operable FDG avid O/GOJ adenocarcinoma treated with perioperative chemotherapy. All patients were reclassified according to the new AJCC8 clinical staging. Prognostic factors for time-to-progression (TTP) and overall survival (OS) were explored.

RESULTS

Of 430 patients included in the study, 180 (41.9%) had FDG avid RLN at baseline PET/CT scan before starting perioperative chemotherapy. The presence of FDG avid RLN was significantly and independently associated with shorter TTP and OS, especially in clinical stage III patients (p < .001 in both cases). Stage III patients with FDG avid RLN had similar TTP and OS to those with stage IVA. Classifying stage III patients with FDG avid RLN into stage IVA led to a significant improvement of the prognostic accuracy of the new AJCC8 clinical staging system (Harrell's concordance index improved from 0.555 to 0.588, p < .001). Of 430 patients starting perioperative chemotherapy, 332 underwent radical tumour resection. The presence of FDG avid RLN before starting perioperative chemotherapy could additionally predict a significantly shorter postoperative time-to-relapse and OS (p < .001 in both cases).

CONCLUSIONS

We propose that the incorporation of RLN status (by FDG PET/CT scan) into the AJCC8 staging system of O/GOJ adenocarcinoma improves its prognostic accuracy and may also improve treatment stratification.

Neoadjuvant treatment of locally advanced esophageal and junctional cancer: the evidence-base, current key questions and clinical trials

Recent trials, including CROSS, MAGIC, ACCORD, and OEO2, have established neoadjuvant therapy as standard of care for locally advanced (cT_2-3N_anyM₀) esophageal and junctional cancer compared with surgery alone. The CROSS trial in particular defines a new benchmark for outcomes from multimodal therapy, with a 5 year survival rate of 47%, a median survival of 47 months, a pathologic complete response rate (pCR) of 29% and an R0 resection rate of 92%. Several key questions remain, in particular whether CROSS-regimen chemoradiotherapy is superior to neoadjuvant chemotherapy alone for esophageal cancer, in particular adenocarcinoma. Second, with respect to neoadjuvant chemoradiation, whether an apparent complete clinical response can justify a "watch and wait" surveillance policy, with salvage surgery reserved for where relapse occurs. Third, whether with modern staging, predicted node negative cT2 tumors merit neoadjuvant therapy as standard. Finally, with the enormous interest in the application of targeted and immune-based therapies, and positive leads from other cancers, whether such approaches can improve outcomes in patients undergoing treatment with curative intent. We review herein a brief overview of the existing evidence-base and current active trials addressing these key questions.

Neoadjuvant treatment of locally advanced esophageal and junctional cancer: the evidence-base, current key questions and clinical trials

Recent trials, including CROSS, MAGIC, ACCORD, and OEO2, have established neoadjuvant therapy as standard of care for locally advanced (cT_2-3N_anyM₀) esophageal and junctional cancer compared with surgery alone. The CROSS trial in particular defines a new benchmark for outcomes from multimodal therapy, with a 5 year survival rate of 47%, a median survival of 47 months, a pathologic complete response rate (pCR) of 29% and an R0 resection rate of 92%. Several key questions remain, in particular whether CROSS-regimen chemoradiotherapy is superior to neoadjuvant chemotherapy alone for esophageal cancer, in particular adenocarcinoma. Second, with respect to neoadjuvant chemoradiation, whether an apparent complete clinical response can justify a "watch and wait" surveillance policy, with salvage surgery reserved for where relapse occurs. Third, whether with modern staging, predicted node negative cT2 tumors merit neoadjuvant therapy as standard. Finally, with the enormous interest in the application of targeted and immune-based therapies, and positive leads from other cancers, whether such approaches can improve outcomes in patients undergoing treatment with curative intent. We review herein a brief overview of the existing evidence-base and current active trials addressing these key questions.

18F-FDG PET Response After Induction Chemotherapy Can Predict Who Will Benefit from Subsequent Esophagectomy After Chemoradiotherapy for Esophageal Adenocarcinoma

This study aimed to determine whether ¹⁸F-FDG PET response after induction chemotherapy before concurrent chemoradiotherapy can identify patients with esophageal adenocarcinoma who may benefit from subsequent esophagectomy. Methods: We identified and analyzed 220 patients with esophageal adenocarcinoma who had received induction chemotherapy before chemoradiotherapy, with or without surgery, with curative intent; all underwent ¹⁸F-FDG PET scanning before and after induction chemotherapy. ¹⁸F-FDG PET responders were defined as patients who achieved complete response (CR) after induction chemotherapy (maximum SUV ≤ 3.0). The predictive value of ¹⁸F-FDG PET response for patient outcomes was evaluated. Results: Overall, 86 patients had bimodality therapy (BMT; induction chemotherapy + chemoradiotherapy) and 134 had trimodality therapy (TMT; induction chemotherapy + chemoradiotherapy with surgery). Forty-eight patients (21.8%) achieved an ¹⁸F-FDG PET CR after induction chemotherapy. ¹⁸F-FDG PET CR was found to correlate with overall survival (OS) and progression-free survival (PFS) in BMT patients. For TMT patients, ¹⁸F-FDG PET CR predicted pathologic response (P = 0.003) but not survival. Among ¹⁸F-FDG PET nonresponders, TMT patients had significantly better survival than did BMT patients (P < 0.001). However, among ¹⁸F-FDG PET responders, BMT patients had OS (P = 0.201) and PFS (P = 0.269) similar to that of TMT patients. After propensity score-matched analysis, ¹⁸F-FDG PET responders treated with BMT versus TMT still had comparable OS and PFS, but TMT was associated with better locoregional control. Conclusion:¹⁸F-FDG PET response to induction chemotherapy could be a useful imaging biomarker to identify patients with esophageal adenocarcinoma who could benefit from subsequent esophagectomy after chemoradiotherapy. Compared with BMT, TMT can significantly improve survival in ¹⁸F-FDG PET nonresponders. However, outcomes for ¹⁸F-FDG PET responders were similar after either treatment (BMT or TMT). Prospective validation of these findings is warranted.

New approaches in esophageal carcinomas

New approaches in the treatment of esophageal cancer comprise endoscopy with refinements of esophagoscopic intraluminal resection by endoscopic submucosal dissection. Radical open surgery is more and more replaced by minimally invasive esophagectomy (MIO), especially in the hybrid technique with laparoscopic gastrolysis and transthoracic esophageal resection and gastric pull-up. Total MIO also in the robotic technique has not yet shown that it produces superior results than the hybrid technique. Fluorescent dye can improve the intraoperative visualization of the vascularization of the gastric conduit. The individualization of neoadjuvant therapy is the magic word in clinical research of multimodal treatment of esophageal cancer. This means response prediction based on molecular markers or clinical response evaluation. The documentation of the diversity of postoperative complications is now standardized by an international consensus. The value of enhanced recovery after surgery is not yet approved compared to conventional management.