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

18Fluorodeoxyglucose positron emission tomography (18F-FDG PET)-derived tumoral and peritumoral radiomic parameters can predict pathological subtype and survival in esophageal carcinoma

AIM

The aim of this study is to investigate the importance of the quantitative parameters of the tumoral and peritumoral regions in prediction of pathological subtypes and 1-year survival in patients with esophageal carcinoma.

MATERIALS AND METHODS

A total of 103 patients with esophageal squamous cell carcinoma (SCC) and adenocarcinoma (AC) and in whom 18fluorodeoxyglucose positron emission tomography/computerized tomography (18F-FDG PET/CT) was performed were included in the study. One-year progression-free survival (PFS) and overall survival times of all patients were noted. Primary tumor and peritumoral area were drawn with manual segmentation on the 18F-FDG PET images. Seventy-three quantitative parameters were extracted from tumoral and peritumoral volumes of interest by using software. The differences of parameters of tumoral and peritumoral regions were determined statistically between pathological subtypes and between 1-year survivors and non-survivors.

RESULTS

Diagnostic models were created with the statistically significant parameters. The model that consists of a tumoral and a peritumoral parameter could classify the pathological subtypes in 61% of the patients correctly (area under the curve [AUC]: 0.706, 61.2% accuracy, 53.7% sensitivity, and 75% specificity). The model that was created with 2 tumoral parameters could classify the 1-year survival in 66% of the patients correctly (AUC: 0.695, 66% accuracy, 73.6% sensitivity, and 56.1% specificity). The model consisting of a tumoral and a peritumoral parameter detected 1-year PFS in 66% of the patients accurately (AUC: 0.687, 66% accuracy, 72.4% sensitivity, and 55.6% specificity).

CONCLUSION

The quantitative parameters obtained from tumoral and peritumoral regions can provide information about pathological subtypes and 1-year survival in esophageal carcinoma.

Comparison of esophageal cancer survival after neoadjuvant chemoradiotherapy plus surgery versus definitive chemoradiotherapy: A systematic review and meta-analysis

Surgery after neoadjuvant chemoradiotherapy remains the gold standard for the treatment of resectable esophageal cancer (EC); however, chemoradiotherapy without surgery has been recommended in specific cases. The aim of this meta-analysis is to analyse the survival between surgeries after neoadjuvant chemoradiotherapy compared with definitive chemoradiotherapy in order to provide a theoretical basis for clinically individualised differential treatment. We conducted an initial search of MEDLINE (PubMed), the Cochrane Library, and Embase for English-only articles that compared treatment regimens and provided survival data. According to the final I2 value of the two survival indicators, the random effect model or fixed effect model was used to calculate the overall hazard ratio (HR) and 95% confidence intervals (CI). Cochrane's Q test was used to judge the heterogeneity of the studies, and a funnel plot was used to evaluate for publication bias. A sensitivity analysis was performed to verify the stability of the included studies. A total of 38 studies involving 29161 patients (neoadjuvant therapy: 15401, definitive chemoradiotherapy: 13760) were included in the analysis. The final pooled results (HR = 0.74, 95% CI: 0.67-0.82) showed a statistically significant increase in overall survival with neoadjuvant chemoradiotherapy plus surgery compared with definitive chemoradiotherapy. Subgroup analyses were performed to determine the effects of heterogeneity, additional treatment regimens, study types, and geographic regions, as well as histologic differences, complications, and recurrence, on the overall results. For people with esophageal cancer that can be removed, neoadjuvant chemoradiotherapy combined with surgery improves survival compared to definitive chemoradiotherapy. However, more research is needed to confirm these results and help doctors make decisions about treatment.

A Review of Advances in Radiotherapy in the Setting of Esophageal Cancers

Esophageal cancer is the eighth most common cancer worldwide and is the sixth most common cause of cancer-related mortality. The paradigm has shifted to include a multimodality approach with surgery, chemotherapy, targeted therapy (including immunotherapy), and radiation therapy. Advances in radiotherapy through techniques such as intensity modulated radiotherapy and proton beam therapy have allowed for the more dose homogeneity and improved organ sparing. In addition, recent studies of targeted therapies and predictive approaches in patients with locally advanced disease provide clinicians with new approaches to modify multimodality treatment to improve clinical outcomes.

Early prediction of residual disease after neoadjuvant chemoradiotherapy and cetuximab for locally advanced esophageal cancer using 18F-FDG PET-CT imaging: a prospective cohort study

Background

Previous studies in locally advanced esophageal cancer (LAEC) suggested that a change in the tumor's metabolic response, i.e., decrease of its interim ¹⁸F-FDG uptake compared with baseline, may predict histopathological response. We evaluated the possible predictive correlation between various PET-CT and histopathological parameters following a neoadjuvant biological-containing chemoradiotherapy (CRT) regimen.

Methods

Patients with resectable LAEC received neoadjuvant cisplatin/5-fluorouracil-based CRT and cetuximab following one cycle of induction chemotherapy and cetuximab. Changes in maximum and mean standardized uptake values (ΔSUV-max and ΔSUV-mean, respectively) and metabolic tumor volume (ΔMTV), measured by PET-CT at baseline and 2 weeks after the onset of treatment, were compared with histopathological findings at surgery. Histopathological response was defined by tumor regression grade (TRG), pathological complete response (pCR) and microscopic or macroscopic residual disease (RD).

Results

Of 18 patients, 13 (72%) with adenocarcinoma (AC) and 5 (28%) with squamous cell carcinoma (SCC), were included. None of the changes in the parameters of PET was associated with pCR; only ΔSUV-mean was associated with TRG in the AC cohort. In contrast, both ΔSUV-mean% and ΔSUV-max% were significantly associated with RD, both in the whole cohort and in the AC cohort. Changes in FDG-uptake predicted RD2 at surgery: only patients with less than 13% decrease in SUV-mean% or less than 29% decrease in SUV-max% had RD2, while all patients with RD0 or RD1 had greater reductions [100% specificity and 100% positive predictive value (PPV)].

Conclusions

Changes in ΔSUV-max and ΔSUV-mean after two weeks of onset of cetuximab-based neoadjuvant chemotherapy for LAEC may predict macroscopic RD but not TRG or pCR at surgery.

Trimodality Therapy vs Definitive Chemoradiation in Older Adults With Locally Advanced Esophageal Cancer

BACKGROUND

The comparative effectiveness of trimodality therapy vs definitive chemoradiation for treating locally advanced esophageal cancer in older adults is uncertain. Existing trials lack generalizability to older adults, a population with heightened frailty. We sought to emulate a hypothetical trial comparing these treatments using real-world data.

METHODS

A cohort of adults aged 66-79 years diagnosed with locally advanced esophageal cancer between 2004 and 2017 was identified in the Surveillance Epidemiology and End Results-Medicare database. The clone-censor-weight method was leveraged to eliminate time-related biases when comparing outcomes between treatments. Outcomes included overall mortality, esophageal cancer-specific mortality, functional adverse events, and healthy days at home.

RESULTS

A total of 1240 individuals with adenocarcinomas and 661 with squamous cell carcinomas were identified. For adenocarcinomas, the standardized 5-year risk of mortality was 73.4% for trimodality therapy and 83.8% for definitive chemoradiation (relative risk [RR] = 0.88, 95% confidence interval [CI] = 0.82 to 0.95). Trimodality therapy was associated with mortality risk reduction for squamous cell carcinomas (RR = 0.87, 95% CI = 0.70 to 1.01). The 1-year incidence of functional adverse events was higher in the trimodality group (adenocarcinomas RR = 1.40, 95% CI = 1.22 to 1.65; squamous cell carcinomas RR = 1.21, 95% CI = 1.00 to 1.49). Over 5 years, trimodality therapy was associated with 160 (95% CI = 67 to 229) and 177 (95% CI = 51 to 313) additional home days in individuals with adenocarcinomas and squamous cell carcinomas, respectively.

CONCLUSIONS

Compared with definitive chemoradiation, trimodality therapy was associated with reduced mortality but increased risk of function-related adverse events. Discussing these tradeoffs may help optimize care plans.

Prognostic Assessment of Interim F18-Fluorodeoxyglucose Positron Emission Tomography in Esophageal Cancer Treated With Chemoradiation With or Without Surgery

Purpose

This study aimed to evaluate if the F18-fluorodeoxyglucose positron emission tomography (F18-FDG PET) response after two weeks of chemoradiation for locoregionally advanced esophageal cancer (staged Tumor (T) 3 and/or Nodes (N)+ Metastases (M) 0) was linked to the pathologic response for patients undergoing surgery, to disease-free survival (DFS) or overall survival (OS).

Materials and Methods

Between March 2006 and September 2017, 40 patients were prospectively enrolled in our study, gave written consent, and had PET scans performed before treatment and after two weeks of chemoradiation. One patient did not undergo his two-week PET without informing study coordinators and was excluded from analyses.

Results

The median age at diagnosis was 62 years. Seventy-two percent of patients had N+ disease. Median OS for the entire group was 24 months. Five-year overall survival was 17%. Survival curves for patients with no PET response, minor PET response, or good PET response overlapped and were not statistically different. For the 25 patients who underwent surgery, the positive predictive value (PPV) of the PET response relative to the pathologic response was 75% and the negative predictive value (NPV) was 62%. In study patients, the crude recurrence rate was 68% and there was no correlation between PET response and DFS.

Conclusion

In our study, interim PET response after two weeks of chemoradiation for locoregionally advanced esophageal cancer was not predictive of outcome or pathologic response. Based on our data and current literature, interim PET should not be used to alter treatment (whether to escalate neo-adjuvant treatment or omit surgery).

DCE-MRI radiomics nomogram can predict response to neoadjuvant chemotherapy in esophageal cancer

OBJECTIVES

To assess volumetric DCE-MRI radiomics nomogram in predicting response to neoadjuvant chemotherapy (nCT) in EC patients.

METHODS

This retrospective analysis of a prospective study enrolled EC patients with stage cT1N + M0 or cT2-4aN0-3M0 who received DCE-MRI within 7 days before chemotherapy, followed by surgery. Response assessment was graded from 1 to 5 according to the tumor regression grade (TRG). Patients were stratified into responders (TRG1 + 2) and non-responders (TRG3 + 4 + 5). 72 radiomics features and vascular permeability parameters were extracted from DCE-MRI. The discriminating performance was assessed with ROC. Decision curve analysis (DCA) was used for comparing three different models.

RESULTS

This cohort included 82 patients, and 72 tumor radiomics features and vascular permeability parameters acquired from DCE-MRI. mRMR and LASSO were performed to choose the optimized subset of radiomics features, and 3 features were selected to create the radiomics signature that were significantly associated with response (P < 0.001). AUC of combining radiomics signature and DCE-MRI performance in the training (n = 41) and validation (n = 41) cohort was 0.84 (95% CI 0.57-1) and 0.86 (95% CI 0.74-0.97), respectively. This combined model showed the best discrimination between responders and non-responders, and showed the highest positive and positive predictive value in both training set and test set.

CONCLUSIONS

The radiomics features are useful for nCT response prediction in EC patients.

Response rate and diagnostic accuracy of early PET-CT during neo-adjuvant therapies in oesophageal adenocarcinoma: A systematic review and meta-analysis

PURPOSE

Only 25% of oesophageal adenocarcinoma (OAC) patients have a pathological response to neo-adjuvant therapy (NAT) before oesophagectomy. Early response assessment using PET imaging may help guide management of these patients. We performed a systematic review and meta-analysis to synthesise the evidence detailing response rate and diagnostic accuracy of early PET-CT assessment.

METHODS

We systematically searched several databases including MEDLINE and Embase. Studies with mixed cohorts of histology, tumour location and a repeat PET-CT assessment after more than one cycle of NAT were excluded. Reference standard was pathological response defined by Becker or Mandard classifications. Primary outcome was metabolic response rate after one cycle of NAT defined by a reduction in maximum standardised uptake value (SUVmax) of 35%. Secondary outcome was diagnostic accuracy of treatment response prediction, defined as the sensitivity and specificity of early PET-CT using this threshold. Quality of evidence was also assessed. Random-effects meta-analysis pooled response rates and diagnostic accuracy. This study was registered with PROSPERO (CRD42019147034).

RESULTS

Overall, 1341 articles were screened, and 6 studies were eligible for analysis. These studies reported data for 518 patients (aged 27-78 years; 452 [87.3%] were men) between 2005 and 2020. Pooled sensitivity of early metabolic response to predict pathological response was 77.2% (95% CI 53.2%-100%). Significant heterogeneity existed between studies (I2  = 80.6% (95% CI 38.9%-93.8%), P = .006). Pooled specificity was 75.0% (95% CI 68.2%-82.5%), however, no significant heterogeneity between studies existed (I2  = 0.0% (95% CI 0.0%-67.4%), P = .73).

CONCLUSION

High-quality evidence is lacking, and few studies met the inclusion criteria of this systematic review. The sensitivity of PET using a SUVmax reduction threshold of 35% was suboptimal and varied widely. However, specificity was consistent across studies with a pooled value of 75.0%, suggesting early PET assessment is a better predictor of treatment resistance than of pathological response. Further research is required to define optimal PET-guided treatment decisions in OAC.

Prediction Model of Long-term Survival After Esophageal Cancer Surgery

OBJECTIVE

We aimed to develop prediction models for estimating the long-term survival in patients who have undergone surgery for esophageal cancer.

BACKGROUND

Few prediction models have been developed for the long-term survival in esophageal cancer patients.

METHODS

This nationwide Swedish population-based cohort study included 1542 patients who survived for ≥90 days after esophageal cancer surgery between 1987 and 2010, with follow-up until 2016. Risk prediction models for 1-, 3-, and 5-year all-cause mortality and 3- and 5-year disease-specific mortality were developed using logistic regression. Candidate predictors were established and readily identifiable prognostic factors. The performance of the models was assessed by the area under receiver-operating characteristic curve (AUC) with interquartile range (IQR) using bootstrap cross-validation and risk calibration.

RESULTS

Predictors included in all models were age, sex, pathological tumor stage, tumor histology, and resection margin status. The models also included various additional predictors depending on the outcome, that is, education level, neoadjuvant therapy, reoperation (within 30 d of primary surgery) and comorbidity (Charlson comorbidity index). The AUC statistics after cross-validation were 0.71 (IQR 0.69-0.74) for 1-year, 0.77 (IQR 0.75-0.80) for 3-year, and 0.78 (IQR 0.76-0.81) for 5-year all-cause mortality. The corresponding values were 0.76 (IQR 0.74-0.79) for 3-year and 0.77 (IQR 0.71-0.83) for 5-year disease-specific mortality. All models showed good agreement between the observed and predicted risks.

CONCLUSIONS

These models showed good performance for predicting long-term survival after esophageal cancer surgery and may thus be useful for patients in planning their lives and to guide the postoperative treatment and follow-up.

Prognostic and predictive values of interim 18F-FDG PET during neoadjuvant chemoradiotherapy for esophageal cancer: a systematic review and meta-analysis

PURPOSE

To determine the prognostic and predictive value of early metabolic response assessed by a change in standardized uptake value (SUV) on interim 18F-FDG PET in patients with esophageal cancer undergoing neoadjuvant chemoradiotherapy.

METHODS

PubMed and Embase were searched up until 10 September, 2020, for studies evaluating a change in SUV on interim 18F-FDG PET for predicting a pathologic response, progression-free survival (PFS), or overall survival (OS) in patients with esophageal cancer. The sensitivity and specificity for predicting a pathologic response were pooled using bivariate and hierarchical summary receiver operating characteristic (HSROC) models. Meta-analytic pooled hazard ratios (HRs) and their 95% confidence intervals (CIs) were derived using a random-effects model.

RESULTS

A total of 11 studies (695 patients) were included in the meta-analysis. For nine studies assessing predictive accuracy, the pooled sensitivity and specificity of an early metabolic response for predicting a pathologic response were 0.80 (95% CI 0.61-0.91) and 0.54 (95% CI 0.45-0.63), respectively. The area under the HSROC curve was 0.64 (95% CI 0.60-0.68). Across the nine studies assessing prognostic value, an early metabolic response determined by interim PET showed pooled HRs for predicting PFS and OS of 0.44 (95% CI, 0.30-0.63) and 0.42 (95% CI, 0.31-0.56), respectively.

CONCLUSION

Change in SUV on interim 18F-FDG PET had significant prognostic value and moderate predictive value for a pathologic response in esophageal cancer treated with neoadjuvant chemoradiotherapy. Interim 18F-FDG PET may help prognostic stratification and guide treatment planning in oncologic practice.

18F-FDG PET/CT Metrics Are Correlated to the Pathological Response in Esophageal Cancer Patients Treated With Induction Chemotherapy Followed by Neoadjuvant Chemo-Radiotherapy

Background and Objective

The aim of this study was to assess the ability of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (¹⁸F-FDG PET/CT) to provide functional information useful in predicting pathological response to an intensive neoadjuvant chemo-radiotherapy (nCRT) protocol for both esophageal squamous cell carcinoma (SCC) and adenocarcinoma (ADC) patients.

Material and Methods

Esophageal carcinoma (EC) patients, treated in our Center between 2014 and 2018, were retrospectively reviewed. The nCRT protocol schedule consisted of an induction phase of weekly administered docetaxel, cisplatin, and 5-fluorouracil (TCF) for 3 weeks, followed by a concomitant phase of weekly TCF for 5 weeks with concurrent radiotherapy (50–50.4 Gy in 25–28 fractions). Three ¹⁸F-FDG PET/CT scans were performed: before (PET₁) and after (PET₂) induction chemotherapy (IC), and prior to surgery (PET₃). Correlation between PET parameters [maximum and mean standardized uptake value (SUV_max and SUV_mean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)], radiomic features and tumor regression grade (TGR) was investigated.

Results

Fifty-four patients (35 ADC, 19 SCC; 48 cT3/4; 52 cN+) were eligible for the analysis. Pathological response to nCRT was classified as major (TRG1-2, 41/54, 75.9%) or non-response (TRG3-4, 13/54, 24.1%). A major response was statistically correlated with SCC subtype (p = 0.02) and smaller tumor length (p = 0.03). MTV and TLG measured prior to IC (PET₁) were correlated to TRG1-2 response (p = 0.02 and p = 0.02, respectively). After IC (PET₂), SUV_mean and TLG correlated with major response (p = 0.03 and p = 0.04, respectively). No significance was detected when relative changes of metabolic parameters between PET₁ and PET₂ were evaluated. At textural quantitative analysis, three independent radiomic features extracted from PET₁ images ([JointEnergy and InverseDifferenceNormalized of GLCM and LowGrayLevelZoneEmphasis of GLSZM) were statistically correlated with major response (p < 0.0002).

Conclusions

¹⁸F-FDG PET/CT traditional metrics and textural features seem to predict pathologic response (TRG) in EC patients treated with induction chemotherapy followed by neoadjuvant chemo-radiotherapy. Further investigations are necessary in order to obtain a reliable predictive model to be used in the clinical practice.

Opportunistic body composition evaluation in patients with esophageal adenocarcinoma: association of survival with 18F-FDG PET/CT muscle metrics

OBJECTIVE

¹⁸F-FDG PET is widely used to accurately stage numerous types of cancers. Although ¹⁸F-FDG PET/CT features of tumors aid in predicting patient prognosis, there is increasing interest in mining additional quantitative body composition data that could improve the prognostic power of ¹⁸F-FDG PET/CT, without additional examination costs or radiation exposure. The aim of this study was to determine the association between overall survival and body composition metrics derived from routine clinical ¹⁸F-FDG PET/CT examinations.

METHODS

Patients who received baseline ¹⁸F-FDG PET/CT imaging during workup for newly diagnosed esophageal adenocarcinoma (EAC) were included. From these studies, psoas cross-sectional area (CSA), muscle attenuation (MA), SUV_mean, and SUV_max were obtained. Correlation with overall survival was assessed using a Cox Proportional Hazards model, controlling for age, body mass index, ¹⁸F-FDG dose, glucose level, diabetes status, in-hospital status, and tumor stage.

RESULTS

Among the 59 patients studied, psoas MA and SUV_max were found to be significant predictors of survival (HR 0.94, 95% CI 0.88-0.99, p = 0.04, and HR 0.37, 95% CI 0.14-0.97, p = 0.04, respectively) and remained independent predictors. Psoas CSA and SUV_mean did not significantly influence survival outcomes.

CONCLUSIONS

Characterization of psoas muscles as a surrogate marker for sarcopenia on baseline ¹⁸F-FDG PET/CT imaging is relatively easily obtained and may offer additional prognostic value in patients with EAC.

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.

Definitive Chemoradiotherapy Versus Trimodality Therapy for Resectable Oesophageal Carcinoma: Meta-analyses and Systematic Review of Literature

BACKGROUND

Standard therapy for loco-regionally advanced, resectable oesophageal carcinoma is trimodality therapy (TMT) consisting of neoadjuvant chemoradiotherapy and oesophagectomy. Evidence of survival advantage of TMT over organ-preserving definitive chemoradiotherapy (dCRT) is inconclusive. The aim of this study is to compare survival between TMT and dCRT.

METHODS

A systematic review and meta-analyses were conducted. Randomised controlled trials and observational studies on resectable, curatively treated, oesophageal carcinoma patients above 18 years were included. Three online databases were searched for studies comparing TMT with dCRT. Primary outcomes were 1-, 2-, 3- and 5-year overall survival rates. Risk of bias was assessed using the Cochrane risk of bias tools for RCTs and cohort studies. Quality of evidence was evaluated according to Grading of Recommendation Assessment, Development and Evaluation.

RESULTS

Thirty-two studies described in 35 articles were included in this systematic review, and 33 were included in the meta-analyses. Two-, three- and five-year overall survival was significantly lower in dCRT compared to TMT, with relative risks (RRs) of 0.69 (95% CI 0.57-0.83), 0.76 (95% CI 0.63-0.92) and 0.57 (95% CI 0.47-0.71), respectively. When only analysing studies with equal patient groups at baseline, no significant differences for 2-, 3- and 5-year overall survival were found with RRs of 0.83 (95% CI 0.62-1.10), 0.81 (95% CI 0.57-1.14) and 0.63 (95% CI 0.36-1.12).

CONCLUSION

These meta-analyses do not show clear survival advantage for TMT over dCRT. Only a non-significant trend towards better survival was seen, assuming comparable patient groups at baseline. Non-operative management of oesophageal carcinoma patients might be part of a personalised and tailored treatment approach in future. However, to date hard evidence proving its non-inferiority compared to operative management is lacking.

Fructose 1,6-Bisphosphatase 1 Expression Reduces 18F-FDG Uptake in Clear Cell Renal Cell Carcinoma

Purpose

To determine the relationship between fructose 1,6-bisphosphatase 1 (FBP1) expression and fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) uptake in patients with clear cell renal cell carcinoma (ccRCC), and to investigate how ¹⁸F-FDG uptake and FBP1 expression are related to tumor metabolism and tumor differentiation grade.

Materials and Methods

A total of 54 patients with ccRCC underwent ¹⁸F-FDG combined positron emission tomography and computed tomography (PET/CT) before tumor resection. The maximum standardized uptake value (SUVmax) for the primary tumor was calculated from the ¹⁸F-FDG uptake. The relationship between SUVmax of primary tumor and the expression of FBP1, hexokinase 2 (HK2), and glucose transporter 1 (GLUT1) was analyzed via immunohistochemical analysis.

Results

We identified an inverse relationship between FBP1 expression and SUVmax (P=0.031). SUVmax was higher in patients with high-grade ccRCC (mean, 11.6 ± 5.0) than in those with low-grade ccRCC (mean, 3.8 ± 1.6, P < 0.001). FBP1 expression was significantly lower in patients with high-grade ccRCC (mean, 0.23 ± 0.1) than in those with low-grade ccRCC (mean, 0.57 ± 0.08; P=0.018). FBP1 status could be predicted with an accuracy of 66.7% when a SUVmax cutoff value of 3.55 was used. GLUT1 expression in ccRCC was positively correlated with ¹⁸F-FDG uptake and FBP1 status, whereas HK2 expression was not.

Conclusion

SUVmax in patients with ccRCC is inversely associated with the expression of FBP1, and FBP1 may inhibit ¹⁸F-FDG uptake via regulating GLUT1. SUVmax is higher in patients with high-grade ccRCC than in those with low-grade ccRCC, which could be the result of lower FBP1 expression in patients with high-grade ccRCC.