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

Impact of Thoracic Duct Resection on Long-Term Survival After Esophagectomy: Individual Patient Data Meta-analysis

BACKGROUND

Radical esophagectomy, including thoracic duct resection (TDR), has been proposed to improve regional lymphadenectomy and possibly reduce the risk of locoregional recurrence. However, because of its impact on immunoregulation, some authors have expressed concerns about its possible detrimental effect on long-term survival. The purpose of this review was to assess the influence of TDR on long-term survival.

PATIENTS AND METHODS

PubMed, MEDLINE, Scopus, and Web of Science databases were searched through 15 March 2024. Overall survival (OS), cancer specific survival (CSS), and disease-free survival (DFS) were primary outcomes. Restricted mean survival time difference (RMSTD), risk ratio (RR), standardized mean difference (SMD), and 95% confidence intervals (CI) were used as pooled effect size measures. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology was employed to evaluate the certainty of evidence.

RESULTS

The analysis included six studies with 5756 patients undergoing transthoracic esophagectomy. TDR was reported in 49.1%. Patients' ages ranged from 27 to 79 years and 86% were males. At 4-year follow-up, the multivariate meta-analysis showed similar results for the comparison noTDR versus TDR in term of OS [- 0.8 months, 95% confidence interval (CI) - 3.1, 1.3], CSS (0.1 months, 95% CI - 0.9, 1.2), and DFS (1.5 months, 95% CI - 2.6, 5.5). TDR was associated with a significantly higher number of harvested mediastinal lymph nodes (SMD 0.57, 95% CI 0.01-1.13) and higher risk of postoperative chylothorax (RR = 1.32; 95% CI 1.04-2.23). Anastomotic leak and pulmonary complications were comparable.

CONCLUSIONS

TDR seems not to improve long-term OS, CSS, and DFS regardless of tumor stage. Routine TDR should not be routinely recommended during esophagectomy.

Identifying intense inflammatory subtype of esophageal squamous cell carcinoma using clustering approach

OBJECTIVE

To establish a risk-stratification system for predicting the postoperative recurrence of esophageal squamous cell carcinoma, this study aimed to evaluate the prognostic value of clusters based on blood inflammation and coagulation markers and investigate their correlation with serum cytokines and genetic alteration.

METHOD

This single-center, retrospective cohort study enrolled 491 patients with esophageal cancer who underwent subtotal esophagectomy between 2004 and 2012. For cluster exploration, nonhierarchical cluster analysis and k-means were applied using serum C-reactive protein, albumin, fibrinogen, and platelet-lymphocyte ratio as variables. Then, multivariate survival analysis was conducted to investigate the association of clusters with recurrence-free survival. To characterize the clusters, serum interleukin-6, interleukin-8, and genetic alteration in primary tumors, the PleSSision-Rapid panel, which can evaluate 160 representative driver genes, was used.

RESULTS

Patients were classified into clusters 1, 2, and 3, which included 24 (5%), 161 (33%), and 306 (62%) patients, respectively. Compared with cluster 3, cluster 1 or 2 had significantly worse recurrence-free survival. Based on the multivariable analysis using cluster, pStage, and age as covariates, cluster was an independent prognostic factor for recurrence-free survival (hazard ratio, 1.55; 95% confidence interval, 1.08-2.21; P = 0.02). The percentage of serum interleukin-6 and interleukin-8 levels was the highest in cluster 1, followed by clusters 2 and 3. In 23 patients with available genomic profiles, no significant difference in representative genomic alterations was observed.

CONCLUSIONS

Non-biased clustering using inflammation and coagulation markers identified the intense inflammatory subtype, which had an independent prognostic effect on recurrence-free survival.

Does Thoracic Duct Ligation at the Time of Esophagectomy Impact Long-Term Survival? An Individual Patient Data Meta-Analysis

Background: Thoracic duct ligation (TDL) during esophagectomy has been proposed to reduce the risk of postoperative chylothorax. Because of its role in immunoregulation, some authors argued that it had an unfavorable TDL effect on survival. The aim of this study was to analyze the effect of TDL on overall survival (OS). Methods: PubMed, MEDLINE, Scopus, and Web of Science were searched through December 2023. The primary outcome was 5-year OS. The restricted mean survival time difference (RMSTD), hazard ratios (HRs), and 95% confidence intervals (CI) were used as pooled effect size measures. The GRADE methodology was used to summarize the certainty of the evidence. Results: Five studies (3291 patients) were included. TDL was reported in 54% patients. The patients' age ranged from 49 to 69, 76% were males, and BMI ranged from 18 to 26. At the 5-year follow-up, the combined effect from the multivariate meta-analysis is -3.5 months (95% CI -6.1, -0.8) indicating that patients undergoing TDL lived 3.5 months less compared to those without TDL. TDL was associated with a significantly higher hazard for mortality at 12 months (HR 1.54, 95% CI 1.38-1.73), 24 months (HR 1.21, 95% CI 1.12-1.35), and 28 months (HR 1.14, 95% CI 1.02-1.28). TDL and noTDL seem comparable in terms of the postoperative risk for chylothorax (RR = 0.66; p = 0.35). Conclusions: In this study, concurrent TDL was associated with reduced 5-year OS after esophagectomy. This may suggest the need of a rigorous follow-up within the first two years of follow-up.

Oncological and physiological impact of thoracic duct resection in esophageal cancer

Despite advances in multidisciplinary treatment, esophagectomy remains the main curative treatment for esophageal cancer. The advantages and disadvantages of thoracic duct (TD) resection have been controversial for decades. We have herein reviewed relevant published literature regarding 'thoracic duct,' 'esophageal cancer,' and 'esophagectomy' describing the anatomy and function of the TD, and incidence of thoracic duct lymph nodes (TDLN) and TDLN metastases, as well as the oncological and physiological effects of TD resection. The presence of lymph nodes around the TD, referred to as TDLN, has been reported previously. The delineation of TDLNs is clearly defined by a thin fascial structure covering the TD and the surrounding adipose tissue. Previous studies have examined the number of TDLNs and the percentage of patients with TDLN metastasis and revealed that each patient had approximately two TDLNs. The percentage of patients with TDLN metastasis was reported to be 6-15%. Several studies have been conducted to compare the survival after TD resection with that after TD preservation. However, no consensus has been reached because all studies were retrospective, precluding firm conclusions. Although the issue of whether the risk of postoperative complications is affected by TD resection is still unclear, resecting the TD has been shown to have a long-term impact on nutritional status after surgery. In summary, TDLNs are quite common and present in most patients, while metastasis in the TDLNs occurs in a minority. However, the oncological value of TD resection in esophageal cancer surgery remains controversial due to varying findings and methodological limitations of previous comparative studies. Considering the potential but unproven oncological benefits and possible physiological drawbacks of TD resection, including postoperative fluid retention and disadvantages in the long-term nutritional outcome, clinical stage, and nutritional status should be considered before deciding whether to perform TD resection or not.

The impact of thoracic duct resection on the long-term body composition of patients who underwent esophagectomy for esophageal cancer and survived without recurrence

BACKGROUND

We have reported the possible benefits of radical esophagectomy with thoracic duct (TD) resection in elective esophageal cancer surgery. However, the effect of TD resection on the long-term nutrition status remains unclear.

METHODS

Patients who underwent esophagectomy at Keio University between January 2006 and December 2018 were included, and those who had no recurrence for more than three years were evaluated. Changes in each body composition (muscle mass and body fat) were comparatively assessed between those who underwent TD resection or not, before and at, one, three and five years after surgery. Computed tomography images were analyzed on postoperative year 1, 3 and 5.

RESULTS

This study included 217 patients categorized in the TD-resected (TD-R) (156 patients) and TD-preserved (TD-P) (61 patients) groups. The loss of muscle mass was comparable between the groups. On the other hand, the loss of adipose tissues was significantly greater in the TD-R group than in the TD-P group at one and three years after surgery, while there was no statistical difference five years after surgery. Additionally, among patients with cT1N0M0 disease in whom survival advantage of TD resection has been reported previously, the loss of muscle mass did not differ between each group.

CONCLUSIONS

The change of muscle mass between the two groups was comparable. Although body fat mass was reduced by TD resection, it eventually recovered in the long term. In patients with esophageal cancer, TD resection may be acceptable without significant impact on body composition in the long term.

Prognosis of Patients with Esophageal Carcinoma After Routine Thoracic Duct Resection: A Propensity-matched Analysis of 12,237 Patients Based on the Comprehensive Registry of Esophageal Cancer in Japan

OBJECTIVE

To clarify whether routine thoracic duct (TD) resection improves the prognosis of patients with esophageal cancer after radical esophagectomy.

SUMMARY OF BACKGROUND DATA

Although TD resection can cause nutritional disadvantage and immune suppression, it has been performed for the resection of surrounding lymph nodes.

METHODS

We analyzed 12,237 patients from the Comprehensive Registry of Esophageal Cancer in Japan who underwent esophagectomy between 2007 and 2012. TD resection and preservation groups were compared in terms of prognosis, perioperative outcomes, and initial recurrent patterns using strict propensity score matching. Particularly, the year of esophagectomy and history of primary cancer of other organs were added as covariates.

RESULTS

After propensity score matching, 1638 c-Stage I-IV patients participated in each group. The 5 year overall survival and cause-specific survival rates were 57.5% and 65.6% in the TD-resected group and 55.2% and 63.4% in the TD-preserved group, respectively, without significant differences. The TD-resected group had significantly more retrieved mediastinal nodes (30 vs 21, P < 0.0001) and significantly fewer lymph node recurrence (376 vs 450, P = 0.0029) compared with the TD-preserved group. However, the total number of distant metastatic organs was significantly greater in TD-resected group than in the TD-preserved group (499 vs 421, P = 0.0024).

CONCLUSIONS

TD resection did not improve survival in patients with esoph-ageal cancer. Despite having retrieved more lymph nodes, TD resection caused distant metastases in more organs compared to TD preservation. Hence, prophylactic TD resection should not be recommended in patients with esophageal cancer.

Standard Lymphadenectomy for Esophageal and Lung Cancer: Variability in the Number of Examined Lymph Nodes Among Pathologists and Its Survival Implication

AIM

We compared variability in number of examined lymph nodes between pathologists and analyzed survival implications in lung and esophageal cancer after standardized lymphadenectomy.

METHODS

Outcomes of 294 N2 dissected lung cancer patients and 132 2-field dissected esophageal cancer patients were retrospectively examined. The primary outcome was difference in reported lymph node count among pathologists. Secondary outcomes were overall and disease-specific survival related to this count and survival related to the 50% probability cut-off value of detecting metastasis based on the number of examined lymph nodes.

RESULTS

The median number of examined lymph nodes in lung cancer was 13 (IQR 9-17) and in esophageal cancer it was 22 (18-29). The pathologist with the highest median number of examined nodes had > 50% higher lymph node yield compared with the pathologist with the lowest median number of nodes in lung (15 vs. 9.5, p = 0.003), and esophageal cancer (28 vs. 17, p = 0.003). Survival in patients stratified by median reported lymph node count in both lung (adjusted RMST ratio < 14 vs. ≥ 14 lymph nodes 0.99, 95% CI 0.88-1.10; p = 0.810) and esophageal cancer (adjusted RMST ratio < 25 vs. ≥ 25 lymph nodes 0.95, 95% CI 0.79-1.15, p = 0.612) was similar. The cut-off value for 50% probability of detecting metastasis by number of examined lymph nodes in lung cancer was 15.7 and in esophageal cancer 21.8. When stratified by this cut-off, no survival differences were seen.

CONCLUSION

The quality of lymphadenectomy based on lymph node yield is susceptible to error due to detected variability between pathologists in the number of examined lymph nodes. This variability in yield did not have any survival effect after standardized lymphadenectomy.

Tumor Burden Monitoring with Circulating Tumor DNA During Treatment in Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND

To guide appropriate treatment strategy, an accurate tumor monitoring modality that reflects tumor burden during neoadjuvant treatment is required for esophageal squamous cell carcinoma (ESCC). We aimed to investigate the clinical utility of circulating tumor DNA (ctDNA) in plasma in patients who received neoadjuvant chemotherapy (NAC) followed by esophagectomy.

PATIENTS AND METHODS

Longitudinally collected plasma samples for ctDNA combined with genomic DNA from primary lesions were obtained from patients with histologically confirmed ESCC who underwent NAC followed by subtotal esophagectomy. Next-generation sequencing was performed to identify mutations from the plasma and the primary tumor. The relationships between changes in ctDNA and the pathological response and recurrence were assessed in patients with locally advanced ESCC.

RESULTS

In pretreatment samples from 13 patients, multiple concordant mutations in ctDNA and primary tumors were observed in 11 patients (85%), who were classified as ctDNA positive before treatment. The ctDNA positive rate after NAC correlated with the pathological response (responders, 25%; nonresponders, 100%; p = 0.007). The risk of recurrence increased significantly in patients with positive ctDNA after surgery in analysis of 16 patients; the 1-year recurrence-free survival rates were 90 and 0% in ctDNA-negative and ctDNA-positive groups, respectively (p = 0.0008). In two patients with postoperative recurrence, ctDNA was detected approximately 5.5 months earlier than the diagnosis using radiographical imaging.

CONCLUSIONS

ctDNA is a promising biomarker for predicting pathological response and postoperative recurrence in ESCC. To demonstrate the external validity, we are currently preparing a multicenter prospective study.

Effect of Postoperative Oral Intake Status on Sarcopenia Six Months After Esophageal Cancer Surgery

PURPOSE

In patients with esophageal cancer, skeletal muscle mass has been reported to decrease progressively after surgery and be independently associated with a poor prognosis. The purpose of this study was to investigate perioperative changes in dysphagia, oral intake status, and nutritional status and identify factors related to sarcopenia 6 months after esophagectomy.

METHODS

A total of 134 patients who underwent radical resection for thoracic esophageal cancer between March 2016 and July 2019 were analyzed retrospectively. The diagnosis of sarcopenia was made by CT taken 6 months postoperatively using the cut-off criteria of skeletal muscle index (SMI) < 52.4 cm²/m² for male and SMI < 38.5 cm²/m² for female patients. As factors related to postoperative sarcopenia, dysphagia, oral intake status, nutritional status, and physical function were extracted from the medical records. Multivariate logistic regression analysis was performed to identify perioperative risk factors related to sarcopenia 6 months after surgery.

RESULTS

Of the 134 patients, 34.3% were judged to be unable to start oral intake on swallowing assessment. At discharge, 30.6% received tube feeding with or without oral intake. In the non-oral intake group on swallowing assessment, a significantly higher proportion of patients received tube feeding at discharge (p = 0.014). Preoperative BMI, postoperative handgrip strength, and tube feeding at discharge were independent risk factors for sarcopenia 6 months after esophagectomy in male patients.

CONCLUSION

Tube feeding at discharge is significantly related to postoperative sarcopenia in patients with esophageal cancer. Identifying high-risk groups might allow early detection of malnutrition and provision of appropriate care.

Implementation of the Esophagectomy Complication Consensus Group definitions: the benefits of speaking the same language

In 2015 the Esophagectomy Complication Consensus Group (ECCG) reported consensus definitions for complications after esophagectomy. This aimed to reduce variation in complication reporting, attributed to heterogeneous definitions. This systematic review aimed to describe the implementation of this definition set, including the effect on complication frequency and variation. A systematic literature review was performed, identifying all observational and randomized studies reporting complication frequencies after esophagectomy since the ECCG publication. Recruitment periods before and subsequent to the index ECCG publication date were included. Coefficients of variance were calculated to assess outcome heterogeneity. Of 144 studies which met inclusion criteria, 70 (48.6%) used ECCG definitions. The median number of separately reported complication types was five per study; only one study reported all ECCG complications. The coefficients of variance of the reported frequencies of eight of the 10 most common complications were reduced in studies which used the ECCG definitions compared with those that did not (P = 0.036). Among ECCG studies, the frequencies of postoperative pneumothorax, reintubation, and pulmonary emboli were significantly reduced in 2020-2021, compared with 2015-2019 (P = 0.006, 0.034, and 0.037 respectively). The ECCG definition set has reduced variation in esophagectomy morbidity reporting. This adds greater confidence to the observed gradual improvement in outcomes with time, and its ongoing use and wider dissemination should be encouraged. However, only a handful of outcomes are widely reported, and only rarely is it used in its entirety.

Intraoperative visualization of morphological patterns of the thoracic duct by subcutaneous inguinal injection of indocyanine green in esophagectomy for esophageal cancer

To prevent chylothorax after esophageal cancer surgery, it is important to recognize morphological patterns of the thoracic duct intraoperatively. The present study aimed to evaluate the safety and usefulness of near-infrared (NIR) fluorescence imaging with subcutaneous inguinal injection of indocyanine green (SII-ICG) to detect the thoracic duct during thoracoscopic esophagectomy for esophageal cancer. Patients (n = 16) who underwent thoracoscopic esophagectomy in the prone position with SII-ICG at Shinshu University Hospital between June 2020 and January 2022 were enrolled in the present study and retrospectively reviewed. Immediately prior to thoracoscopic esophagectomy, we injected 0.2-0.5 mg/kg ICG into the subcutaneous tissue in the bilateral inguinal region. The identification rate of the thoracic duct was 93.8% (n = 15), and the success rate of fluorescence using SII-ICG was 87.5% (n = 14). The visible thoracic ducts had four patterns: a typical pattern in 50% (n = 8), duplication pattern in 18.8% (n = 3), branching pattern in 12.5% (n = 2), and plexiform pattern in 12.5% (n = 2). In all cases, ICG fluorescence did not disappear and was visible during the thoracic surgery. No SII-ICG-related complications were observed. Intraoperative NIR fluorescence imaging of the thoracic duct using SII-ICG is a simple and safe method with very high detection sensitivity. This method can be a powerful tool for avoiding thoracic duct injuries during esophageal cancer surgery.

Elevation of the Prognostic Factor Plasma Fibrinogen Reflects the Immunosuppressive Tumor Microenvironment in Esophageal Squamous Cell Carcinoma

INTRODUCTION

Despite previous reports on the clinical significance of plasma fibrinogen (FNG) levels as a prognostic indicator of ESCC, its underlying mechanism remains unclear. This study aimed to validate the prognostic impact of plasma FNG levels and clarify its relationship with primary tumors in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

The prognostic impact of FNG was evaluated in patients with ESCC who underwent esophagectomy between 2000 and 2019. The RNA sequencing of the primary ESCC site, which was from pre-operative biopsy, was performed, followed by immune profile characterization using an immunogram. Those profiles were assessed via the immunohistochemical staining of tumor-associated macrophages (TAMs) and clinical response to nivolumab.

RESULTS

Multivariate analysis identified FNG as a significant prognostic factor in ESCC. The immunogram suggested an immunosuppressive tumor environment in the high-FNG group. Immunostaining with the TAM markers CD163 and CD204, revealed that the high-FNG group had significantly higher number of TAMs compared with the low-FNG group. The immunosuppressive characteristics were clinically validated in patients with metastatic ESCC; those who had elevated FNG levels showed poor response to nivolumab.

CONCLUSION

This study successfully validated the prognostic impact of plasma FNG levels in an expanded cohort with ESCC. Accordingly, our findings showed that increased plasma FNG reflects an immunosuppressive tumor microenvironment that facilitates tumor progression and poor responses to nivolumab.

Effectiveness of lymphadenectomy along the thoracic duct for radical esophagectomy

BACKGROUND

There has been much debate on whether to perform TD resection in radical esophagectomy for esophageal cancer from the perspectives of metastatic rate, effect on postoperative hemodynamics, and other factors. The objective of this study was to determine whether TDLN dissection contributes to improved prognosis.

METHODS

This study involved 1211 patients who underwent D2/D3 dissection with TD resection for thoracic esophageal cancer between 1984 and 2020. The lymph nodes along the TD were defined as TDLNs and the remaining No. 112 nodes as non-TDLNs. The metastatic rate in TDLNs and non-TDLNs and their outcomes were compared with those of other thoracic lymph nodes. Correlation with the invasion depth of the main lesion was also analyzed (T0-2 545 patients, T3-4 666 patients).

RESULTS

The metastatic rates in TDLNs/non-TDLNs in all patients were 7.3%/7.5%, respectively, while those in T0-2 were 2.2%/3.9%, and those in T3-4 were 11.5%/10.6%, with both having higher rates in advanced cases. The efficacy index (EI) for lymphadenectomy in T3-4 was 2.94 for TDLNs and 3.44 for non-TDLNs, with no significant difference. The metastatic rate in TDLNs by tumor site was as follows: Ut/Mt/Lt = 1.1/2.4/2.4% (T0-2) and 7.7/14.5/8.4% (T3-4), being especially high (~ 15%) in patients with advanced cases in Mt region. The EI was comparable or higher for TDLNs compared with other group-2 (Mt/Lt) and group-3 (Ut) regional lymph nodes, regardless of site.

CONCLUSIONS

The significance of TD resection was low in T0-2 due to the low metastatic rate but became evident in cases with invasion depth of T3-4. TDLN resection was at least as effective as dissection of other group-2 or -3 lymph nodes, including No. 112 nodes.

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.

Nutritional Outcomes of Thoracic Duct Resection for Radical Esophagectomy by Assessing Body Composition Changes in One Year: A Single-Center Retrospective Study

BACKGROUND

Thoracic duct (TD) resection is performed when the tumor or a metastatic lymph node directly invades the TD, and is sometimes indicated for radical lymphadenectomy during esophagectomy in esophageal cancer patients. However, the effect of TD resection on nutritional status has not been established.

PATIENTS AND METHODS

In total, 174 consecutive patients from October 2015 to March 2019 who underwent radical esophagectomy for esophageal cancer in Toranomon Hospital were classified into thoracic duct preserved group (n = 51) and TD-resected (TD-R) group (n = 123). We compared laboratory data, body composition data from bioelectrical impedance analysis measured preoperatively and at 1 and 12 months after surgery, and postoperative complications between the two groups.

RESULTS

Clinical stage was significantly more advanced in the TD-R group. Total body weight, body mass index, and fat mass continuously decreased in the two groups over 12 months after surgery, and the decreases were statistically greater in the TD-R group at 12 months after surgery. Skeletal muscle mass and fat-free mass decreased over 1 month after surgery and stayed in a reduced state until 12 months after surgery without statistically significant differences between the two groups. TD resection did not increase incidence of postoperative complications (Clavien-Dindo classification ≥ grade III), but TD resection increased incidence of chylothorax.

CONCLUSIONS

Our results suggest that loss of body fat mass, which was a main contributor to body weight loss, was accelerated in the TD-R group, but TD resection does not deteriorate loss of muscle mass at 12 months after surgery.

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.

The presence of metastatic thoracic duct lymph nodes in Western esophageal cancer patients

BACKGROUND

The thoracic lymphadenectomy during an esophagectomy for esophageal cancer includes resection of the thoracic duct (TD) compartment containing the thoracic duct lymph nodes (TDLN). However, the role of TD compartment resection is still a topic of debate since metastatic TDLNs have only been demonstrated in squamous cell carcinomas in Eastern esophageal cancer patients. Therefore, the aim of this study was to assess the presence and metastatic involvement of TDLNs in a Western population, in which adenocarcinoma is the predominant type of esophageal cancer.

METHODS

From July 2017 to May 2020 all consecutive patients undergoing an open or robot-assisted transthoracic esophagectomy with concurrent lymphadenectomy and resection of the TD compartment in the University Medical Center Utrecht, The Netherlands and the Città della Salute e della Scienza University Hospital in Turin, Italy were included. The TD compartment was resected en bloc and was separated in the operation room by the operating surgeon after which it was macro- and microscopically assessed for (metastatic) TDLNs by the pathologist.

RESULTS

A total of 117 patients with an adenocarcinoma (73%) or squamous cell carcinoma (27%) of the esophagus were included. In 61 (52%) patients TDLNs were found, containing metastasis in 9 (15%) patients. No major complications related to TD compartment resection were observed.

CONCLUSIONS

This is the first study to demonstrate the presence of metastatic TDLNs in adenocarcinomas of the esophagus. This result provides a valid argument to routinely extend the thoracic lymphadenectomy with resection of the TD compartment during an esophagectomy for esophageal cancer.

The effect of prophylactic thoracic duct ligation during esophagectomy on the incidence of chylothorax and survival of the patients: an updated review

BACKGROUND

The role of thoracic duct ligation (TDL) during esophagectomy remains controversial. This review aimed to elucidate the effect of TDL on chylothorax and survival of the patients after esophagectomy for cancer.

METHODS

We searched articles from PubMed, Web of Science, Scopus, Cochrane, and Google Scholar till May 2020 according to the PRISMA guidelines using the terms of [Oesophagectomy OR esophagectomy] AND [chylothorax] AND [thoracic duct ligation]. Only those compared the incidence of chylothorax in patients who ligated or resected the thoracic duct (ligation group) or preserved the thoracic duct (preservation group) were selected.

RESULTS

First, 15 studies including one randomized controlled trial were collected for meta-analysis regarding post-esophagectomy chylothorax. Of these, 3658 patients underwent TDL and 4638 cases preserved the thoracic duct. Both groups showed similar chylothorax rate (odd ratios 0.73 in favor of ligation group; 95% confidence interval [CI] 0.50-1.07, p = 0.11). Second, four studies providing survival information were included for another meta-analysis, and the patients in preservation group demonstrated better 5-year overall survival compared to those in ligation group (odds ratio 1.25; 95% CI 1.08-1.44, p = 0.002).

CONCLUSIONS

The present review provided updated evidence opposing prophylactic TDL during esophagectomy for lowering chylothorax. Considering the harmful effect of TDL on survival of the patients, further well-designed trials should be considered in selected cases under strict supervision.