Discrepancy Between the Clinical and Final Pathological Findings of Lymph Node Metastasis in Superficial Esophageal Cancer

Radiomics diagnostic performance for predicting lymph node metastasis in esophageal cancer: a systematic review and meta-analysis

BACKGROUND

Esophageal cancer, a global health concern, impacts predominantly men, particularly in Eastern Asia. Lymph node metastasis (LNM) significantly influences prognosis, and current imaging methods exhibit limitations in accurate detection. The integration of radiomics, an artificial intelligence (AI) driven approach in medical imaging, offers a transformative potential. This meta-analysis evaluates existing evidence on the accuracy of radiomics models for predicting LNM in esophageal cancer.

METHODS

We conducted a systematic review following PRISMA 2020 guidelines, searching Embase, PubMed, and Web of Science for English-language studies up to November 16, 2023. Inclusion criteria focused on preoperatively diagnosed esophageal cancer patients with radiomics predicting LNM before treatment. Exclusion criteria were applied, including non-English studies and those lacking sufficient data or separate validation cohorts. Data extraction encompassed study characteristics and radiomics technical details. Quality assessment employed modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and Radiomics Quality Score (RQS) tools. Statistical analysis involved random-effects models for pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC). Heterogeneity and publication bias were assessed using Deek's test and funnel plots. Analysis was performed using Stata version 17.0 and meta-DiSc.

RESULTS

Out of 426 initially identified citations, nine studies met inclusion criteria, encompassing 719 patients. These retrospective studies utilized CT, PET, and MRI imaging modalities, predominantly conducted in China. Two studies employed deep learning-based radiomics. Quality assessment revealed acceptable QUADAS-2 scores. RQS scores ranged from 9 to 14, averaging 12.78. The diagnostic meta-analysis yielded a pooled sensitivity, specificity, and AUC of 0.72, 0.76, and 0.74, respectively, representing fair diagnostic performance. Meta-regression identified the use of combined models as a significant contributor to heterogeneity (p-value = 0.05). Other factors, such as sample size (> 75) and least absolute shrinkage and selection operator (LASSO) usage for feature extraction, showed potential influence but lacked statistical significance (0.05 < p-value < 0.10). Publication bias was not statistically significant.

CONCLUSION

Radiomics shows potential for predicting LNM in esophageal cancer, with a moderate diagnostic performance. Standardized approaches, ongoing research, and prospective validation studies are crucial for realizing its clinical applicability.

Outcomes of patients with esophageal squamous cell carcinoma who achieved a pathological complete response in the primary lesion by neoadjuvant treatment: a Japanese nationwide cohort study

BACKGROUND

Minimal data was reported regarding the characteristics, risks of lymph node metastasis, and prognostic factors in esophageal cancer patients who achieved remarkable response in the primary lesion to neoadjuvant treatment (NAT).

METHODS

This study evaluated the nationwide data of esophageal squamous cell carcinoma (ESCC) patients who underwent surgery following NAT in Japan. Of 4484 patients, 300 (6.7%) had ypT0 following NAT and curative esophagectomy. Factors associated with lymph node metastasis and prognosis were analyzed.

RESULTS

Neoadjuvant chemotherapy (NAC) and neoadjuvant chemoradiotherapy (NACRT) were administered in 260 (86.2%) and 40 (13.8%) patients, respectively. Pathologically, 72 (24.0%) had lymph node metastasis (residual nodal disease; RND), and pretherapeutic lymph node metastasis was the independent risk factor for RND (odd ratio [OR]: 3.21; 95% confidence interval [CI]: 1.44-8.20; P = 0.008). The 5-year overall and relapse-free survivals were significantly longer in patients with pathological complete response (pCR) than in those with RND (both P < 0.001). Pretherapeutic cT3 or T4a tumors (hazard ratio [HR]: 1.71; 95% CI: 1.02-2.88; P = 0.043), RND (HR: 3.30; 95% CI: 1.98-5.50; P < 0.001), and operative blood loss (Liter, HR: 1.53; 95% CI: 1.07-2.19; P = 0.021) were independent risk factors affecting relapse-free survival in multivariable analysis.

CONCLUSIONS

Of patients with ypT0 after NAT, 24.0% had RND, and pretherapeutic lymph node metastasis was the risk factor. In addition, pretherapeutic cT3, or T4a tumors, RND, and operative blood loss were the poor prognosticators in patients with ypT0 after NAT.

Endoscopic Evaluation of Pathological Complete Response Using Deep Neural Network in Esophageal Cancer Patients Who Received Neoadjuvant Chemotherapy-Multicenter Retrospective Study from Four Japanese Esophageal Centers

BACKGROUND

Detecting pathological complete response (pCR) before surgery would facilitate nonsurgical approach after neoadjuvant chemotherapy (NAC). We developed an artificial intelligence (AI)-guided pCR evaluation using a deep neural network to identify pCR before surgery.

METHODS

This study examined resectable esophageal squamous cell carcinoma (ESCC) patients who underwent esophagectomy after NAC. The same number of histological responders without pCR and non-responders were randomly selected based on the number of pCR patients. Endoscopic images were analyzed using a deep neural network. A test dataset consisting of 20 photos was used for validation. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of AI and four experienced endoscopists' pCR evaluations were calculated. For pathological response evaluation, Japanese Classification of Esophageal Cancer was used.

RESULTS

The study enrolled 123 patients, including 41 patients with pCR, the same number of histological responders without pCR, and non-responders [grade 0, 5 (4%); grade 1a, 36 (30%); grade 1b, 21 (17%); grade 2, 20 (16%); grade 3, 41 (33%)]. In 20 models, the median values of sensitivity, specificity, PPV, NPV, and accuracy for endoscopic response (ER) detection were 60%, 81%, 77%, 67%, and 70%, respectively. Similarly, the endoscopists' median of these was 43%, 90%, 85%, 65%, and 66%, respectively.

CONCLUSIONS

This proof-of-concept study demonstrated that the AI-guided endoscopic response evaluation after NAC could identify pCR with moderate accuracy. The current AI algorithm might guide an individualized treatment strategy including nonsurgical approach in ESCC patients through prospective studies with careful external validation to demonstrate the clinical value of this diagnostic approach including primary tumor and lymph node.

Prognostic impact of endoscopic response evaluation after neoadjuvant chemotherapy for esophageal squamous cell carcinoma: a nationwide validation study

BACKGROUND

Our previous study reported the prognostic significance of endoscopic response (ER) evaluation, defined ER, and revealed ER as an independent prognostic factor of overall survival (OS) and recurrence-free survival (RFS) for esophageal squamous cell carcinoma (ESCC) treated with neoadjuvant chemotherapy (NAC) and surgery. The present study aimed to validate the prognostic impact of ER using a nationwide database from the authorized institute for board-certified esophageal surgeons by the Japan Esophageal Society.

METHODS

This study retrospectively reviewed patients with ESCC who underwent subtotal esophagectomy at 85 authorized institutes for esophageal cancer from 2010 to 2015. Patients were classified as ER when the tumor size was markedly reduced post-NAC compared to pre-NAC. The correlation between OS and RFS was investigated.

RESULTS

Of 4781 patients initially enrolled, 3636 were selected for subsequent analysis. Of them, 642 (17.7%) patients were classified as the ER group. Patients with ER showed significantly better OS and RFS. Subgroup analysis revealed the statistical difference in OS and RFS in cStage II and III, while the magnitude of survival difference between ER and non-ER was not evident in cStage I and IV. The percentage of ER varied from 46 to 87% among groups when institutions were classified into 3 subgroups based on the hospital volume, which would indicate the interinstitutional inconsistency.

CONCLUSIONS

The prognostic impact of ER was validated using a nationwide database. Standardization of ER evaluation is required to improve the interinstitutional consistency and clinical validity of the ER evaluation.

Machine learning models predict lymph node metastasis in patients with stage T1-T2 esophageal squamous cell carcinoma

Background

For patients with stage T1-T2 esophageal squamous cell carcinoma (ESCC), accurately predicting lymph node metastasis (LNM) remains challenging. We aimed to investigate the performance of machine learning (ML) models for predicting LNM in patients with stage T1-T2 ESCC.

Methods

Patients with T1-T2 ESCC at three centers between January 2014 and December 2019 were included in this retrospective study and divided into training and external test sets. All patients underwent esophagectomy and were pathologically examined to determine the LNM status. Thirty-six ML models were developed using six modeling algorithms and six feature selection techniques. The optimal model was determined by the bootstrap method. An external test set was used to further assess the model’s generalizability and effectiveness. To evaluate prediction performance, the area under the receiver operating characteristic curve (AUC) was applied.

Results

Of the 1097 included patients, 294 (26.8%) had LNM. The ML models based on clinical features showed good predictive performance for LNM status, with a median bootstrapped AUC of 0.659 (range: 0.592, 0.715). The optimal model using the naive Bayes algorithm with feature selection by determination coefficient had the highest AUC of 0.715 (95% CI: 0.671, 0.763). In the external test set, the optimal ML model achieved an AUC of 0.752 (95% CI: 0.674, 0.829), which was superior to that of T stage (0.624, 95% CI: 0.547, 0.701).

Conclusions

ML models provide good LNM prediction value for stage T1-T2 ESCC patients, and the naive Bayes algorithm with feature selection by determination coefficient performed best.

The Least Nodal Disease Burden Defines the Minimum Number of Nodes Retrieved for Esophageal Squamous Cell Carcinoma

Background

Clinically, a single positive lymph node (SPLN) should indicate the least nodal disease burden in node-positive patients with esophageal squamous cell carcinoma (ESCC) and may also be used to define the minimum number of examined lymph nodes (NELNs) in ESCC patients.

Methods

Data from three Chinese cohorts of 2448 ESCC patients who underwent esophagectomy between 2008 and 2012 were retrospectively analyzed. Based on lymph node status, patients were divided into two groups: N0 ESCC and SPLN ESCC. A Cox proportional hazards regression model was used to determine the minimum NELNs retrieved to maximize survival for ESCC patients with localized lymph node involvement. The results were then validated externally in the SEER database.

Results

A total of 1866 patients were pathologically diagnosed with N0 ESCC, and 582 patients were diagnosed with SPLN ESCC. The overall survival rate of patients with N0 ESCC was significantly better than that of patients with SPLN ESCC (HR 1.88, 95% CI 1.64-2.13, P<0.001), but no significant difference was found between SPLN ESCC patients with ≥ 20 lymph nodes harvested and N0 ESCC patients (HR 1.20, 95% CI 0.95-1.52, P=0.13). Analysis of patients selected from the SEER database showed the same trend, and no significant difference was observed between N0 ESCC patients and SPLN ESCC patients with ≥ 20 lymph nodes retrieved (HR: 1.02, 95% CI 0.72-1.43, P=0.92).

Conclusions

A minimum of 20 lymph nodes retrieved should be introduced as a quality indicator for ESCC patients with localized lymph node involvement.

A Population-Based Study: How to Identify High-Risk T1-2 Esophageal Cancer Patients?

Background

Due to individualized conditions of lymph node metastasis (LNM) and distant metastasis (DM), the following therapeutic strategy and diagnosis of T1-2 esophageal cancer (ESCA) patients are varied. A prediction model for identifying risk factors for LNM, DM, and overall survival (OS) of high-risk T1-2 ESCA patients is of great significance to clinical practice.

Methods

A total of 1,747 T1-2 ESCA patients screened from the surveillance, epidemiology, and end results (SEER) database were retrospectively analyzed for their clinical data. Univariate and multivariate logistic regression models were established to screen out risk factors for LNM and DM of T1-2 ESCA patients, while those of OS were screened out using the Cox regression analysis. The identified risk factors for LNM, DM, and OS were then subjected to the establishment of three nomograms, respectively. The accuracy of the nomograms was evaluated by depicting the calibration curve, and the predictive value and clinical utility were evaluated by depicting the clinical impact curve (CIC) and decision curve analysis (DCA), respectively.

Results

The age, race, tumor grade, tumor size, and T-stage were significant factors for predicting LNM of T1-2 ESCA patients (p < 0.05). The age, T-stage, tumor grade, and tumor size were significant factors for predicting DM of T1-2 ESCA patients (p < 0.05). The age, race, sex, histology, primary tumor site, tumor size, N-stage, M-stage, and surgery were significant factors for predicting OS of T1-2 ESCA patients (p < 0.05). The C-indexes of the three nomograms constructed by these factors were 0.737, 0.764, and 0.740, respectively, suggesting that they were clinically effective.

Conclusions

The newly constructed nomograms can objectively and accurately predict the LNM, DM, and OS of T1-2 ESCA patients, which contribute to the individualized decision making before clinical management.

Clinical Significance of Endoscopic Response Evaluation to Predict the Distribution of Residual Tumor after Neoadjuvant Chemotherapy for Esophageal Squamous Cell Carcinoma

PURPOSE

To appropriately adopt the organ preservation approach, including subsequent chemoradiotherapy (CRT) in patients who respond to neoadjuvant chemotherapy (NAC), the distribution of residual disease, including pathological lymph nodes (LNs) and recurrence site, needs to be recognized preoperatively. This study was designed to evaluate whether endoscopic response evaluation can predict residual tumor distribution.

METHODS

Patients with esophageal squamous cell carcinoma who underwent transthoracic esophagectomy (TTE) were retrospectively reviewed. Endoscopic responder (ER) to NAC was defined according to primary tumor endoscopic findings. Recurrence-free survival (RFS), overall survival (OS), and residual tumor patterns were compared between groups.

RESULTS

Of 193 patients, 40 (20%) were classified as ER. ERs showed significantly better RFS and OS. The pN location was found within the primary tumor and cN field in 88% of ERs, which was significantly higher than non-ERs at 63% (p = 0.004). Furthermore, the postoperative recurrence incidence in the distant organ was significantly lower in the ERs than the non-ERs (8%, 32%, respectively, p = 0.002). Residual disease, including postoperative initial recurrence, existed within the same field as the primary tumor and cN in 88% of ERs, significantly higher than 42% in the non-ERs (p < 0.001).

CONCLUSIONS

Endoscopic response evaluation can preoperatively predict distribution of residual tumors after NAC, which could help radiation field selection in subsequent definitive CRT when patients prefer to omit TTE. Along with improvements in NAC response rate, this could facilitate organ preservation in patients who respond to NAC.

SLC7A9 as a Potential Biomarker for Lymph Node Metastasis of Esophageal Squamous Cell Carcinoma

BACKGROUND

The expression of solute carrier (SLC) 7 family genes is reportedly associated with several malignancies. Here, we focused on SLC7A9 and investigated its expression, function, and clinical significance in esophageal squamous cell carcinoma (ESCC).

METHODS

SLC7A9 transcription levels were evaluated in 13 ESCC cell lines, and polymerase chain reaction (PCR) array analysis was conducted to detect coordinately expressed genes with SLC7A9. SLC7A9 contributions to proliferation, invasion, and migration were evaluated in ESCC cells subjected to siRNA-mediated gene knockdown and pCMV6-entry plasmid-mediated overexpression. SLC7A9 expression was detected in 189 ESCC tissues by quantitative reverse-transcription (qRT)-PCR and correlated with clinicopathological parameters.

RESULTS

The expression levels of SLC7A9 varied widely in ESCC cell lines and correlated with FGFBP1 expression. Knockdown of SLC7A9 significantly suppressed the proliferation, invasion, and migration of the ESCC cell lines. Moreover, overexpression of SLC7A9 enhanced cell proliferation and migration. In analyses of clinical specimens, SLC7A9 mRNA was overexpressed in the ESCC tissues compared with the adjacent normal esophageal tissues. High mRNA expression was significantly associated with high levels of squamous cell carcinoma-related antigen and carcinoembryonic antigen, advanced disease stage, and lymph node metastasis. High SLC7A9 expression was also significantly associated with poor disease-specific and disease-free survival, and lymph node recurrence after radical surgery, but not with the other recurrence patterns. On multivariate analysis, high SLC7A9 expression was an independent predictor of lymph node recurrence.

CONCLUSIONS

SLC7A9 influences the malignant behavior of ESCC cells. Tumor SLC7A9 expression may serve as a novel biomarker for predicting lymph node metastasis and recurrence in ESCC patients.

Lymphocyte-to-C-Reactive Protein Ratio as a Novel Marker for Predicting Oncological Outcomes in Patients with Esophageal Cancer

BACKGROUND

Esophageal cancer has a poor prognosis because of its rapid progression and early and extensive lymph node metastasis. Simple, objective indicators for predicting long-term outcomes are needed to select optimal perioperative treatment and appropriate follow-up for patients with esophageal cancer. The aim of this study is to investigate the relationship between the lymphocyte-to-C-reactive protein ratio (LCR) and the survival of patients with esophageal cancer, by performing time-dependent receiver operating characteristic (ROC) curve analysis. The results were compared to those of traditional inflammation-based markers.

METHODS

This study enrolled 495 patients who underwent thoracic esophagectomy for esophageal cancer as the primary treatment between 2000 and 2019 in our department. We investigated the predictability of the LCR for oncological outcomes compared to that of other traditional inflammatory markers.

RESULTS

The 3-year overall survival (OS) and recurrence-free survival (RFS) were 72.6% and 57.5%, respectively. Low LCR was significantly associated with higher cancer stage, included depth of invasion (p < 0.001), lymph node metastasis (p < 0.001) and cStage (p < 0.001). The LCR had the highest AUC value (0.675) for predicting OS compared to the other examined inflammatory markers. In multivariate analysis, the LCR (optimal cutoff threshold = 19,000) was identified as a significant predictor of death (hazard ratio, 2.24; 95% confidence interval [CI], 1.61-3.12; p < 0.001) and recurrence (hazard ratio, 1.97; 95%CI, 1.48-2.63; p < 0.001).

CONCLUSION

The LCR is novel indicator for oncological outcomes for patients with esophageal cancer and may assist to facilitate personalized multidisciplinary treatments.

A nomogram for predicting lymph node metastasis in superficial esophageal squamous cell carcinoma

Superficial esophageal squamous cell carcinoma (SESCC) is defined as carcinoma with mucosal or submucosal invasion, regardless of regional lymph node metastasis (LNM). The lymph node status is not only a key factor to determine the training strategy, but also the most important prognostic factor in esophageal cancer. In this study, we establish a clinical nomogram for predicting LNM in patients with SESCC. A predictive model was established based on the training cohort composed of 711 patients who underwent esophagectomy for SESCC from December 2009 to June 2018. A prospective cohort of 203 patients from June 2018 to January 2019 was used for validation. Favorable calibration and well-fitted decision curve analysis were conducted and good discrimination was observed (concordance index [C-index], 0.860; 95% confidence interval [CI], 0.825–0.894) through internal validation. The external validation cohort presented good discrimination (C-index, 0.916; 95% CI, 0.860–0.971). This model may facilitate the prediction of LNM in patients with SESCCs.

Clinical impact of abdominal versus mediastinal metastases as a prognostic factor for poor outcomes following esophageal cancer surgery: a retrospective study

Background

Surgery is still the mainstay of radical treatment for resectable esophageal cancer (EC). It is apparent that the presence or spread of lymph node metastasis (LNM) is a powerful prognostic factor in patients with EC who are eligible for curative treatment. Although the importance and efficacy of lymph node dissection in radical esophagectomy have been reported, the clinical or prognostic relevance of specific metastatic patterns within the mediastinal cavity and abdomen remains unclear.

Methods

We retrospectively analyzed the association of postoperative survival with clinical mediastinal LNM (cMLNM) and abdominal LNM (cALNM) in 157 patients who underwent radical EC surgery at our hospital between May 2012 and March 2018.

Results

A significant difference in cause-specific survival (CSS) was observed between patients with and without cALNM (log-rank p = 0.000). A multivariate Cox regression analysis revealed that cALNM and thoracic surgery (mediastinal lymphadenectomy via conventional open right thoracotomy or video-assisted thoracoscopic surgery) independently predicted CSS (p = 0.0007 and 0.021, respectively). Moreover, a significant difference in systemic recurrence-free survival was observed between those with and without cALNM (log-rank p = 0.000). Multivariate Cox regression analysis revealed that cALNM and sex independently predicted systemic recurrence-free survival (p = 0.000 and 0.015, respectively).

Conclusion

cALNM was an independent poor prognostic factor for CSS after EC surgery. It may also be an independent prognostic factor for postoperative systemic recurrence, which can shorten the CSS. For patients with cALNM-positive EC who have a high potential risk of systemic metastases, more extensive treatment besides the conventional perioperative systemic chemotherapy may be necessary.

Prognostic impact of thoracic duct lymph node metastasis in esophageal squamous cell carcinoma

AIM

We have previously reported the existence of lymph nodes surrounding the thoracic duct ( TDLN) and transthoracic esophagectomy (TTE) with thoracic duct (TD) resection increased the number of lymph nodes (LNs) retrieved. The current study aims to evaluate the prognostic impact of TDLN metastasis in esophageal cancer patients subdivided by its location and comparing the patients' survival with those with extra-regional LN metastasis.

METHODS

Patients who underwent TTE with TD resection for esophageal squamous cell carcinoma (ESCC) were reviewed. Patients were classified into those with or without TDLN metastasis, and clinicopathological factors were compared between groups. TDLN was further divided into TDLN-Ut/Mt/Lt based on the location in the mediastinum. The relapse-free survival (RFS) and overall survival (OS) were compared between groups.

RESULTS

Of 232 patients, TDLN metastasis was observed in 17 (7%). RFS and OS were significantly worse in the TDLN metastasis group. TDLN metastasis was shown to be an independent prognostic factor for RFS and OS in the multivariate analysis. The negative prognostic impact of TDLN metastasis was evident in TDLN-Mt/Lt. The RFS and OS of patients with TDLN metastasis were almost identical to those with positive LN metastasis in extra-regional LNs.

CONCLUSION

TDLN metastasis was proven to be a strong prognostic indicator. Although the TDLN has been included in the classification of regional LN in the current staging systems, it could be independently classified from the current regional LNs. Given that neoadjuvant therapy has been a standard, we might need to introduce adjuvant therapy when TDLN metastasis is observed.

A nomogram to predict lymph node metastasis risk for early esophageal squamous cell carcinoma

Background

A nomogram was developed to predict lymph node metastasis (LNM) for patients with early-stage esophageal squamous cell carcinoma (ESCC).

Methods

We used the clinical data of ESCC patients with pathological T1 stage disease who underwent surgery from January 2011 to June 2018 to develop a nomogram model. Multivariable logistic regression was used to confirm the risk factors for variable selection. The risk of LNM was stratified based on the nomogram model. The nomogram was validated by an independent cohort which included early ESCC patients underwent esophagectomy between July 2018 and December 2019.

Results

Of the 223 patients, 36 (16.1%) patients had LNM. The following three variables were confirmed as LNM risk factors and were included in the nomogram model: tumor differentiation (odds ratio [OR] = 3.776, 95% confidence interval [CI] 1.515–9.360, p = 0.004), depth of tumor invasion (OR = 3.124, 95% CI 1.146–8.511, p = 0.026), and tumor size (OR = 2.420, 95% CI 1.070–5.473, p = 0.034). The C-index was 0.810 (95% CI 0.742–0.895) in the derivation cohort (223 patients) and 0.830 (95% CI 0.763–0.902) in the validation cohort (80 patients).

Conclusions

A validated nomogram can predict the risk of LNM via risk stratification. It could be used to assist in the decision-making process to determine which patients should undergo esophagectomy and for which patients with a low risk of LNM, curative endoscopic resection would be sufficient.

Risk factors for lymph node metastasis in T1 esophageal squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND

Lymph node metastasis (LNM) affects the application and outcomes of endoscopic resection in T1 esophageal squamous cell carcinoma (ESCC). However, reports of the risk factors for LNM have been controversial.

AIM

To evaluate risk factors for LNM in T1 ESCC.

METHODS

We searched Embase, PubMed and Cochrane Library to select studies related to LNM in patients with T1 ESCC. Included studies were divided into LNM and non-LNM groups. We performed a meta-analysis to examine the relationship between LNM and clinicopathologic features. Odds ratio (OR), mean differences and 95% confidence interval (CI) were assessed using a fixed-effects or random-effects model.

RESULTS

Seventeen studies involving a total of 3775 patients with T1 ESCC met the inclusion criteria. After excluding studies with heterogeneity based on influence analysis, tumor size (OR = 1.93, 95%CI = 1.49-2.50, P < 0.001), tumor location (OR = 1.46, 95%CI = 1.17-1.82, P < 0.001), macroscopic type (OR = 3.17, 95%CI = 2.33-4.31, P < 0.001), T1 substage (OR = 6.28, 95%CI = 4.93-8.00, P < 0.001), differentiation (OR = 2.11, 95%CI = 1.64-2.72, P < 0.001) and lymphovascular invasion (OR = 5.86, 95%CI = 4.60-7.48, P < 0.001) were found to be significantly associated with LNM. Conversely, sex, age and infiltrative growth pattern were not identified as risk factors for LNM.

CONCLUSION

A tumor size > 2 cm, lower location, nonflat macroscopic type, T1b stage, poor differentiation and lymphovascular invasion were associated with LNM in patients with T1 ESCC.

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

Effect of azygos arch preservation during thoracoscopic esophagectomy on facilitation of postoperative refilling

PURPOSE

In esophageal cancer surgery, the significance of preserving the azygos arch during thoracoscopic esophagectomy remains unknown. To determine the significance, we examined the difference in postoperative courses between patients who underwent an azygos arch-preserving technique and patients whose azygos arch had been dissected.

METHODS

We retrospectively analyzed 119 patients with esophageal cancer who underwent thoracoscopic esophagectomy from January 2017 to December 2019. Statistical tests, including univariate or multivariate analyses and propensity score-matched analysis, were performed focusing on changes in fluid balance caused by the preservation of the azygos arch.

RESULTS

The azygos arch was preserved in 65 patients and dissected in 54 patients. Urine output on postoperative day 2 was higher, and the IN-OUT balance on postoperative day 2 or accumulated IN-OUT balance up to postoperative day 2 tended to be lower in the azygos arch-preserving group than in the dissected group. The azygos arch-preserving technique did not affect the number of dissected mediastinal lymph nodes.

CONCLUSION

The azygos arch-preserving technique during thoracoscopic esophagectomy facilitated postoperative refilling and avoided postoperative fluid excess. This technique might be a novel minimally invasive option for an otherwise highly invasive esophageal cancer surgery.

Distribution of Lymph Node Metastasis in Esophageal Squamous Cell Carcinoma After Trimodal Therapy

BACKGROUND

Although metastatic tumors in lymph nodes (LN) are potentially affected by neoadjuvant chemoradiotherapy (NCRT), the distribution of LN metastases of esophageal squamous cell carcinoma (ESCC) after trimodal therapy has never been sufficiently estimated.

PATIENTS AND METHODS

We evaluated the distribution of LN metastases, relationships between LN metastases and radiation fields, risk factors for LN metastasis, and the influence of LN metastasis on the survival of 184 patients with ESCC who underwent NCRT followed by esophagectomy.

RESULTS

Neoadjuvant chemoradiotherapy resulted in down-staged LN status in 74 (49.3%) patients. Pathological LN metastases were extensive in 177 LN stations in the cervical, mediastinal, and abdominal fields, and 162 (91.5%) metastases were located inside the radiation fields. Multivariate analysis showed that clinical N stage [N0 vs. 1/2/3: hazard ratio (HR), 2.69; 95% confidence interval (CI), 1.22-5.92; p = 0.01] and clinical response of primary tumor (complete vs. noncomplete: HR, 2.93; 95% CI, 1.50-5.69; p = 0.002) were statistically significant for pathological LN metastasis. Recurrence-free and overall survivals were significantly stratified according to the number of pathological LN metastases, associations between clinical and pathological LN metastases, and presence or absence of pathological LN metastases outside radiation field.

CONCLUSIONS

About 50% of patients who were clinically diagnosed with LN metastasis before treatment were downstaged by NCRT, and their prognoses were relatively good. However, LN metastases were extensive at the cervical, mediastinal, and abdominal areas, even within the radiation field. Thus, systematic and adequate lymphadenectomy is required for ESCC treated by NCRT.

Lymph Node and Bone Marrow Micrometastases Define the Prognosis of Patients with pN0 Esophageal Cancer

BACKGROUND

Pathological routine lymph node staging is postulated to be the main oncological prognosticator in esophageal cancer (EC). However, micrometastases in lymph nodes (LNMM) and bone marrow (BNMM) are discussed as the key events in tumor recurrence. We assessed the prognostic significance of the LNMM/BNMM status in initially pN0 staged patients with curative esophagectomy.

METHODS

From 110 patients bone marrow aspirates and lymph node tissues were analyzed. For LNMM detection immunohistochemistry was performed using the anticytokeratin antibody AE1/AE3. To detect micrometastases in the bone marrow a staining with the pan-keratin antibody A45-B/B3 was done. Results were correlated with clinicopathologic parameters as well as recurrence and death during follow-up time.

RESULTS

Thirty-eight (34.5%) patients showed LNMM, whereas in 54 (49.1%) patients BNMM could be detected. LNMM and BNMM positive patients showed a correlation to an increased pT category (p = 0.017). Univariate and multivariate analyses revealed that the LNMM/BNMM status and especially LNMM skipping the anatomical lymph node chain were significant independent predictors of overall survival and recurrence-free survival.

CONCLUSIONS

This study indicates that routine pathological staging of EC is insufficient. Micrometastases in lymph nodes and the bone marrow seem to be the main reason for tumor recurrence and they are a strong prognosticator following curative treatment of pN0 EC.

Minimally invasive oesophagectomy with extended lymph node dissection and thoracic duct resection for early-stage oesophageal squamous cell carcinoma

BACKGROUND

Oesophageal squamous cell carcinoma is an aggressive disease owing to early and widespread lymph node metastases. Multimodal therapy and radical surgery may improve prognosis. Few studies have investigated the efficacy of radical lymph node and thoracic duct resection.

METHODS

Patients with oesophageal squamous cell carcinoma who underwent transthoracic minimally invasive oesophagectomy (TMIE) for cancer at Keio University Hospital between January 2004 and December 2016 were selected. Between 2004 and 2008, TMIE was performed in the lateral decubitus position without thoracic duct resection (standard TMIE). From 2009 onwards, TMIE with extended lymph node and thoracic duct resection was introduced (extended TMIE). Demographics, co-morbidity, number of retrieved lymph nodes, pathology, postoperative complications and recurrence-free survival (RFS) were compared between groups.

RESULTS

Forty-four patients underwent standard TMIE and 191 extended TMIE. There were no significant differences in clinical and pathological tumour stage or postoperative complications. The extended-TMIE group had more lymph nodes removed at nodal stations 106recL and 112. Among patients with cT1 N0 disease, RFS was better in the extended-TMIE group (P < 0·001), whereas there was no difference in RFS between groups in patients with advanced disease.

CONCLUSION

Extended TMIE including thoracic duct resection increased the number of lymph nodes retrieved and was associated with improved survival in patients with cT1 N0 oesophageal squamous cell carcinoma.

Association of the primary tumor's SUVmax with survival after surgery for clinical stage IA esophageal cancer: a single-center retrospective study

BACKGROUND

Compared to other esophageal cancers, clinical stage IA esophageal cancer generally has a good prognosis, although a subgroup of patients has a poor prognosis. Unfortunately, clinical diagnoses of invasion depth or lymph node metastasis are not always accurate, which make it difficult to identify patients with a high risk of postoperative recurrence using the tumor-node-metastasis staging system. Fluorodeoxyglucose-positron emission tomography may help guide the identification of malignant tumors and the evaluation of their malignant grade based on glucose metabolism. We aimed to evaluate the association between pre-operative fluorodeoxyglucose-positron emission tomography findings and the postoperative prognosis of patients with clinical stage IA esophageal cancer.

METHODS

This single-center retrospective study evaluated pre-esophagectomy fluorodeoxyglucose-positron emission tomography findings from 38 patients with clinical stage IA esophageal cancer. Receiver operating characteristic curve analysis was performed to evaluate the prognostic significance of the primary tumor having low and high SUVmax values (cut-off: 3.56).

RESULTS

Overall survival (log-rank p = 0.034) and progression-free survival (log-rank p = 0.008) were significantly different between the groups with low SUVmax values (n = 18) and high SUVmax values (n = 20). Furthermore, the primary tumor's SUVmax value was related to pathological vascular invasion (p = 0.045) and distant metastasis (p = 0.042).

CONCLUSION

The SUVmax of the primary tumor is a predictor of postoperative survival for clinical stage IA esophageal cancer. Thus, using fluorodeoxyglucose-positron emission tomography to evaluate the primary tumor's glucose metabolism may reflect the tumor's grade and potentially compensate for inaccuracies in tumor-node-metastasis staging.