Impact of Skeletal Muscle Loss and Sarcopenia on Outcomes of Locally Advanced Esophageal Cancer during Neoadjuvant Chemoradiation

BACKGROUND

The impact of changes in skeletal muscle and sarcopenia on outcomes during neoadjuvant chemoradiotherapy (NACR) for patients with esophageal cancer remains controversial.

PATIENTS AND METHODS

We retrospectively analyzed the data of patients with locally advanced esophageal squamous cell cancer who received NACR followed by esophagectomy between June 2013 and December 2021. The images at third lumbar vertebra were analyzed to measure the cross-sectional area and calculate skeletal muscle index (SMI) before and after NACR. SMI less than 52.4 cm2/m2 for men and less than 38.5 cm2/m2 for women were defined as sarcopenia. The nonlinearity of the effect of percent changes in SMI (ΔSMI%) to survival outcomes was assessed by restricted cubic splines.

RESULTS

Overall, data of 367 patients were analyzed. The survival outcomes between sarcopenia and non-sarcopenia groups had no significant differences before NACR. However, patients in post-NACR sarcopenia group showed poor overall survival (OS) benefit (P = 0.016) and poor disease-free survival (DFS) (P = 0.043). Severe postoperative complication rates were 11.9% in post-NACR sarcopenia group and 5.0% in post-NACR non-sarcopenia group (P = 0.019). There was a significant non-linear relationship between ΔSMI% and survival outcomes (P < 0.05 for non-linear). On the multivariable analysis of OS, ΔSMI% > 12% was the independent prognostic factor (HR 1.76, 95% CI 1.03-2.99, P = 0.039) and significant difference was also found on DFS analysis (P = 0.025).

CONCLUSIONS

Patients with post-neoadjuvant chemoradiotherapy sarcopenia have worse survival and adverse short-term outcomes. Moreover, greater loss in SMI is associated with increased risks of death and disease progression during neoadjuvant chemoradiotherapy, with maximum impact noted with SMI loss greater than 12%.

Impact of deep muscle invasion on nodal status and survival in patients with pT2 esophageal squamous cancer

BACKGROUND

Whether T2 esophageal squamous cell carcinoma should be subclassified remains controversial. We aimed to investigate the impact of the depth of muscularis propria invasion on nodal status and survival outcomes.

METHODS

We identified patients with pT2 esophageal squamous cell carcinoma who underwent primary surgery from January 2009 to June 2017. Clinical data were extracted from prospectively maintained databases. Tumor muscularis propria invasion was stratified into superficial or deep. Binary logistic regression was used to determine risk factors for lymph node metastases. The impact of the depth of muscularis propria invasion on survival was investigated using Kaplan‒Meier analysis and a Cox proportional hazard regression model.

RESULTS

A total of 750 patients from three institutes were investigated. The depth of muscularis propria invasion (odds ratio [OR]: 3.95, 95% confidence interval [CI]: 2.46-6.35; p < 0.001) was correlated with lymph node metastases using logistic regression. T substage (hazard ratio [HR]: 1.37, 95% CI: 1.05-1.79; p < 0.001) and N status (HR: 1.51, 95% CI: 1.05-2.17; p < 0.001) were independent risk factors in multivariate Cox regression analysis. The deep muscle invasion was associated with worse overall survival (HR: 1.52, 95% CI: 1.19-1.94; p = 0.001) than superficial, specifically in T2N0 patients (HR: 1.38, 95% CI: 1.08-1.94; p = 0.035).

CONCLUSIONS

We found that deep muscle invasion was associated with significantly worse outcomes and recommended the substaging of pT2 esophageal squamous cell carcinoma in routine pathological examination.

Increased resected lymph node stations improved survival of esophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) and surgery have been recommended as the standard treatments for locally advanced esophageal squamous cell carcinoma (ESCC). In addition, nodal metastases decreased in frequency and changed in distribution after neoadjuvant therapy. This study aimed to examine the optimal strategy for lymph node dissection (LND) in patients with ESCC who underwent nCRT.

METHODS

The hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were calculated using the Cox proportional hazard model. To determine the minimal number of LNDs (n-LNS) or least station of LNDs (e-LNS), the Chow test was used.

RESULTS

In total, 333 patients were included. The estimated cut-off values for e-LNS and n-LNS were 9 and 15, respectively. A higher number of e-LNS was significantly associated with improved OS (HR: 0.90; 95% CI 0.84-0.97, P = 0.0075) and DFS (HR: 0.012; 95% CI: 0.84-0.98, P = 0.0074). The e-LNS was a significant prognostic factor in multivariate analyses. The local recurrence rate of 23.1% in high e-LNS is much lower than the results of low e-LNS (13.3%). Comparable morbidity was found in both the e-LNS and n-LND subgroups.

CONCLUSION

This cohort study revealed an association between the extent of LND and overall survival, suggesting the therapeutic value of extended lymphadenectomy during esophagectomy. Therefore, more lymph node stations being sampled leads to higher survival rates among patients who receive nCRT, and standard lymphadenectomy of at least 9 stations is strongly recommended.

Vitamin D receptor induces oxidative stress to promote esophageal squamous cell carcinoma proliferation via the p53 signaling pathway

Background

Esophageal squamous cell carcinoma (ESCC) is a common pathological esophageal cancer with poor prognosis. Vitamin D deficiency reportedly occurs in ESCC patients, and this is related to single nucleotide polymorphism of vitamin D receptor (VDR).

Objective

We investigated the effect of VDR on ESCC proliferation, invasion, and metastasis and its potential mechanism.

Methods

ESCC and normal tissues were collected from 20 ESCC patients. The ESCC tissue microarray contained 116 pairs of ESCC and normal tissues and 73 single ESCC tissues. VDR expression and its clinicopathological role were determined by real-time quantitative polymerase chain reaction, Western blot, and immunohistochemistry staining. sh-VDR and VDR overexpression were used to validate the effect of VDR on ESCC cell phenotype, and tandem mass tag-based quantitative proteomics and bioinformatics methods identified differential VDR-related proteins. The downstream pathway and regulatory effect were analyzed using ingenuity pathway analysis (IPA). Differentially expressed proteins were verified through parallel reaction monitoring and Western blot. In vivo imaging visualized subcutaneous tumor growth following tail vein injection of VDR-deficient ESCC cells.

Results

High VDR expression was observed in ESCC tissues and cells. Gender, T stage, and TNM stage were related to VDR expression, which was the independent prognostic factor related to ESCC. VDR downregulation repressed ESCC cell proliferation, invasion, and migration in vitro and subcutaneous tumor growth and lung metastases in vivo. The cell phenotype changes were reversed upon VDR upregulation, and differential proteins were mainly enriched in the p53 signaling pathway. TP53 cooperated with ABCG2, APOE, FTH1, GCLM, GPX1, HMOX1, JUN, PRDX5, and SOD2 and may activate apoptosis and inhibit oxidative stress, cell metastasis, and proliferation. TP53 was upregulated after VDR knockdown, and TP53 downregulation reversed VDR knockdown-induced cell phenotype changes.

Conclusions

VDR may inhibit p53 signaling pathway activation and induce ESCC proliferation, invasion, and metastasis by activating oxidative stress.

[Analysis on the secondary attack rates of SARS-CoV-2 Omicron variant and the associated factors]

Objective: To evaluate the secondary attack rates of the SARS-CoV-2 Omicron variant and the associated factors. Methods: A total of 328 primary cases and 40 146 close contacts of the SARS-CoV-2 Omicron variant routinely detected in local areas of Jiangsu Province from February to April 2022 were selected in this study, and those with positive nucleic acid test results during 7 days of centralized isolation medical observation were defined as secondary cases. The demographic information and clinical characteristics were collected, and the secondary attack rate (SAR) and the associated factors were analyzed by using a multivariate logistic regression model. Results: A total of 1 285 secondary cases of close contacts were reported from 328 primary cases, with a SAR of 3.2% (95%CI: 3.0%-3.4%). Among the 328 primary cases, males accounted for 61.9% (203 cases), with the median age (Q1, Q3) of 38.5 (27, 51) years old. Among the 1 285 secondary cases, males accounted for 59.1% (759 cases), with the median age (Q1, Q3) of 34 (17, 52) years old. The multivariate logistic regression model showed that the higher SAR was observed in the primary male cases (OR=1.632, 95%CI: 1.418-1.877), younger than 20 years old (OR=1.766, 95%CI: 1.506-2.072),≥60 years old (OR=1.869, 95%CI: 1.476-2.365), infected with the BA.2 strain branch (OR=2.906, 95%CI: 2.388-3.537), the confirmed common cases (OR=2.572, 95%CI: 2.036-3.249), and confirmed mild cases (OR=1.717, 95%CI: 1.486-1.985). Meanwhile, the higher SAR was observed in the close contacts younger than 20 years old (OR=2.604, 95%CI: 2.250-3.015),≥60 years old (OR=1.287, 95%CI: 1.052-1.573) and exposure for co-residence (OR=27.854, 95%CI: 23.470-33.057). Conclusion: The sex and age of the primary case of the Omicron variant, the branch of the infected strain, case severity of the primary case, as well as the age and contact mode of close contacts are the associated factors of SAR.

Identification of m6a-related signature genes in esophageal squamous cell carcinoma by machine learning method

Background: We aimed to construct and validate the esophageal squamous cell carcinoma (ESCC)-related m6A regulators by means of machine leaning. Methods: We used ESCC RNA-seq data of 66 pairs of ESCC from West China Hospital of Sichuan University and the transcriptome data extracted from The Cancer Genome Atlas (TCGA)-ESCA database to find out the ESCC-related m6A regulators, during which, two machine learning approaches: RF (Random Forest) and SVM (Support Vector Machine) were employed to construct the model of ESCC-related m6A regulators. Calibration curves, clinical decision curves, and clinical impact curves (CIC) were used to evaluate the predictive ability and best-effort ability of the model. Finally, western blot and immunohistochemistry staining were used to assess the expression of prognostic ESCC-related m6A regulators. Results: 2 m6A regulators (YTHDF1 and HNRNPC) were found to be significantly increased in ESCC tissues after screening out through RF machine learning methods from our RNA-seq data and TCGA-ESCA database, respectively, and overlapping the results of the two clusters. A prognostic signature, consisting of YTHDF1 and HNRNPC, was constructed based on our RNA-seq data and validated on TCGA-ESCA database, which can serve as an independent prognostic predictor. Experimental validation including the western and immunohistochemistry staining were further successfully confirmed the results of bioinformatics analysis. Conclusion: We constructed prognostic ESCC-related m6A regulators and validated the model in clinical ESCC cohort as well as in ESCC tissues, which provides reasonable evidence and valuable resources for prognostic stratification and the study of potential targets for ESCC.

Longer Time Interval from Neoadjuvant Chemoradiation to Surgery is Associated with Poor Survival for Patients Without Clinical Complete Response in Oesophageal Cancer

BACKGROUND

The optimal interval between neoadjuvant therapy and oesophagectomy for oesophageal cancer remains controversial.

METHODS

Patients with locally advanced oesophageal squamous cell carcinoma (ESCC) who received neoadjuvant chemoradiotherapy followed by oesophagectomy between June 2017 and December 2020 were prospectively enrolled and retrospectively analysed. Patients were divided into two groups: timely (group A; < 10 weeks) and delayed (group B; ≥ 10 weeks) surgery groups. Survival was the primary outcome, and tumour response and post-operative complications were the secondary outcomes.

RESULTS

Overall, 224 patients were recruited; 116 patients (51.8%) underwent timely surgery within 10 weeks (group A), and 108 patients (49.2%) underwent delayed surgery over 10 weeks (group B) after chemoradiotherapy. In patients with clinical complete response (cCR), two groups had no significant difference of survival benefit (P = 0.618). However, in patients without cCR, delayed surgery was associated with poor survival (P = 0.035) and cancer progression (P = 0.036). A total of 40 patients (34.5%) in group A and 54 patients (50.0%) in group B achieved pCR (P = 0.019). pCR rates were significantly different across the four groups and increased over time (P = 0.006).

CONCLUSIONS

Patients with a prolonged time interval from neoadjuvant chemoradiation to surgery had higher pCR rates. For patients with cCR to neoadjuvant chemoradiation, the time interval to surgery can be safely prolonged for at least 10 weeks. However, for patients with non-cCR to neoadjuvant chemoradiation, delayed surgery is associated with poor survival, and surgery should be performed within 10 weeks of neoadjuvant chemoradiation.

The prognostic impact of preoperative body mass index changes for patients with esophageal squamous cell carcinoma who underwent esophagectomy: A large-scale long-term follow-up cohort study

Background

This study aims to investigate the relationship between preoperative body mass index changes (ΔBMI) and prognosis in patients with esophageal squamous cell carcinoma who underwent esophagectomy.

Methods

We identified 1,883 patients with esophageal squamous cell carcinoma who underwent curative resection in our department between January 2005 and December 2013. Patients were grouped into a stable body mass index (ΔBMI = 0) group and a decreased body mass index (ΔBMI &lt; 0) group. Risk factors for ΔBMI were assessed using logistic regression analysis. The impact of ΔBMI on survival was investigated using Kaplan–Meier curves and Cox regression. A nomogram for survival prediction was constructed and validated.

Results

The results showed that T stage (OR: 1.30, 95% CI: 1.16–1.45, P &lt; 0.001) and N stage (OR: 1.24, 95% CI: 1.11–1.38, P &lt; 0.001) were independent risk factors for ΔBMI. The ΔBMI &lt; 0 group had worse overall survival than the stable body mass index group (HR: 1.25, 95% CI: 1.08–1.44, P = 0.002). When stratified by stage, ΔBMI had the greatest prognostic impact in stage I tumors (HR: 1.82, 95%: 1.05–3.15, P = 0.033). In addition, multiple comparisons showed that decreasing ΔBMI correlated with worse prognosis. The ΔBMI-based nomogram presented good predictive ability with a C-index of 0.705.

Conclusion

This study demonstrates that ΔBMI &lt; 0 had an adverse impact on the long-term survival of patients with esophageal squamous cell carcinoma undergoing esophagectomy. These results may support further investigation of preoperative nutrition support.

Is Tumor Regression Grade Sufficient to Predict Survival in Esophageal Cancer with Trimodal Therapy?

BACKGROUND

This study aimed to assess the predictive value of tumor regression grade (TRG) and nodal status on survival in esophageal carcinoma with neoadjuvant chemoradiotherapy (nCRT).

METHODS

Tumor pathologic regression and nodal status were assessed. Differences in survival stratified by TRG or nodal status were analyzed using the Kaplan-Meier method and log-rank test. The prognostic value of TRG and nodal status were analyzed using univariate and multivariate Cox proportional hazards methods.

RESULTS

From July 2016 to June 2019, 253 patients with esophageal cancer underwent nCRT followed by surgery. Significant differences were presented in survival according to nodal status but not TRG. Multivariate analysis showed that nodal status and not TRG was the only independent predicter for overall survival (HR: 3.550, 95% CI: 2.264-5.566, P < 0.001) and disease-free survival (HR: 2.801, 95% CI: 1.874-4.187, P < 0.001). The modified TRG system combining tumor regression with nodal status stratified patients survival with good discrimination.

CONCLUSIONS

Lymph node status impacts more importantly than TRG on survival for patients with esophageal cancer undergoing nCRT plus esophagectomy. The modified TRG system may facilitate postoperative treatment decisions and survival surveillance.

Effect of circumferential resection margin status on survival and recurrence in esophageal squamous cell carcinoma with neoadjuvant chemoradiotherapy

Background

The aim of this study was to investigate whether circumferential resection margin (CRM) status has an impact on survival and recurrence in esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy.

Methods

We screened patients with esophageal squamous cell carcinoma who underwent esophagectomy from January 2017 to December 2019. The CRM was reassessed. Patients were grouped into a CRM of 1 mm or less (0 &lt; CRM ≤ 1 mm) and a CRM greater than 1 mm (CRM&gt;1 mm). The impact of CRM on survival was investigated using Kaplan–Meier analysis and Cox regression modeling. The optimal CRM cut point was evaluated using restricted cubic spline curve.

Results

A total of 89 patients were enrolled in this study. The CRM status was an independent risk factor for the prognosis (HR: 0.35, 95% CI: 0.16-0.73). Compared with a CRM of 1 mm or less, a CRM greater than 1 mm had better overall survival (HR: 0.35, 95% CI: 0.16-0.73, log-rank P = 0.011), longer disease-free survival (HR: 0.51, 95% CI: 0.27-0.95, log-rank P = 0.040), and less recurrence (HR: 0.44, 95% CI: 0.23-0.85, log–rank P = 0.015). We visualized the association between CRM and the hazard ratio of survival and identified the optimal cut point at 1 mm.

Conclusions

A CRM greater than 1 mm had better survival and less recurrence compared to a CRM of 1 mm or less. A more radical resection with adequate CRM could benefit survival in patients with esophageal squamous cell carcinoma after neoadjuvant therapy.

The comparisons of neoadjuvant chemoimmunotherapy versus chemoradiotherapy for esophageal squamous cancer

OBJECTIVES

To evaluate the short-term outcomes of neoadjuvant chemoimmunotherapy followed by oesophagectomy for locally advanced oesophageal squamous carcinoma.

METHODS

Patients receiving neoadjuvant chemoimmunotherapy or chemoradiotherapy between September 2019 and September 2021 were identified. The primary outcomes were tumour response and survival. Secondary outcomes were toxic effects and postoperative complications. The propensity score matching for enrolled patients was performed.

RESULTS

Data of 149 patients with clinical stage II-IV oesophageal squamous cancer, including 55 receiving neoadjuvant chemoimmunotherapy and 94 receiving neoadjuvant chemoradiotherapy, were analyzed after propensity score matching. With regard to tumour response score, 24 (43.6%) and 59 (62.8%) patients were scored 0/1 in the neoadjuvant chemoimmunotherapy and neoadjuvant chemoradiotherapy groups, respectively (p = 0.023). Of note, 17 (30.9%) patients in the neoadjuvant chemoimmunotherapy group achieved pathological complete response (ypT0N0), while 48 (51.1%) patients in neoadjuvant chemoradiotherapy group achieved pathological complete response (P = 0.026). Neoadjuvant chemoradiotherapy was associated with higher risk of postoperative pneumonia (p = 0.034) and less lymph nodes and stations dissected (p ≤ 0.001). The 1-year cumulative overall survival rate was 94.5% and 86.2% in the NACI and NACR groups, respectively (p = 0.170).

CONCLUSIONS

We found that neoadjuvant chemoimmunotherapy compared with neoadjuvant chemoradiotherapy was associated with lower pneumonia rate and was safe and feasible for locally advanced oesophageal squamous cancer. However, the tumour regression score and the pathological complete response rate of patients treated with neoadjuvant immunotherapy was lower than those of patients treated with neoadjuvant chemoradiotherapy. The short-term follow-up results were comparable between two treatment modalities.

Safety and Feasibility of Esophagectomy Following Neoadjuvant Immunotherapy Combined with Chemotherapy for Esophageal Squamous Cell Carcinoma

Background

This study aimed to investigate the safety and feasibility of esophagectomy after neoadjuvant immunotherapy and chemotherapy for esophageal squamous cell carcinoma.

Methods

We retrospectively identified patients who received neoadjuvant immunotherapy combined with chemotherapy (n = 38) in our center between 2020 and 2021. The primary end point was the risk of major complications (grade ≥3) according to the Clavien–Dindo classification. Secondary end points were surgical details, 30-day mortality, and 30-day readministration.

Results

The most commonly used regimens of immunotherapy were camrelizumab (36.8%), pembrolizumab (31.5%), tislelizumab (15.8%), sintilimab (13.2%), and toripalimab (2.6%). The median interval to surgery was 63 days (range, 40–147). Esophagectomy was performed in 37 of 38 patients who received neoadjuvant immunotherapy and chemotherapy. All procedures were performed minimally invasively, except for 1 patient who was converted to thoracotomy. Of 37 surgical patients, R0 resection was achieved in 36 patients (97.3%). Pathologic complete response was observed in 9 patients (24.3%). Tumor regression grade I was identified in 17 patients (45.9%). Morbidity occurred in 12 of 37 patients (32.4%). The most common complication was pneumonia (16.2%). There were no deaths or readministration within 30 days.

Conclusions

Esophagectomy following neoadjuvant immune checkpoint inhibitor plus chemotherapy for patients with resectable esophageal squamous cell carcinoma appears to be safe and feasible, with acceptable complication rates.

Efficacy and Safety of Immune Checkpoint Inhibitor in Advanced Esophageal Squamous Cell Carcinoma: A Meta-Analysis

Background

The published evidence from several randomized controlled clinical trials of immunotherapy for advanced esophageal squamous cell carcinoma has shown promising results. This study aimed to investigate the efficacy and safety of immune checkpoint inhibitor treatment in esophageal squamous cell carcinoma.

Methods

PubMed, Web of Science, Cochrane Library, and Embase databases were searched for relevant articles published before December 30, 2020. The data for efficacy and safety of immune checkpoint inhibitor treatment were subjected to meta-analysis.

Results

Seven clinical trials comprising 1733 patients were included. The results showed that immune checkpoint inhibitor treatment as second- or later-line treatment was associated with an increased risk of the objective response rate (relative risk: 1.82, 95% confidence interval: 0.82–4.04; P=0.002) and median overall survival (hazard ratio: 0.75, 95% confidence interval: 0.67–0.85; P<0.001) compared with chemotherapy in locally advanced or metastatic esophageal squamous cell carcinoma. Moreover, immune checkpoint inhibitor treatment was associated with significant improvement in median overall survival (hazard ratio: 0.61, 95% confidence interval: 0.48–0.77, P<0.001) compared with chemotherapy in the programmed death-ligand 1 (PD-L1)-positive population. However, immune checkpoint inhibitor treatment was also effective in all patients independent of PD-L1 expression. The most common grade ≥3 treatment-related adverse events with immune checkpoint inhibitor therapy were anemia, asthenia, rash, fatigue, decreased appetite, diarrhea, pneumonia, decreased neutrophil count, and vomiting. Patients undergoing immune checkpoint inhibitor therapy was associated with a decreased risk of treatment-related adverse events (relative risk: 0.82, 95% confidence interval: 0.62–1.08; P<0.001) and grade ≥3 treatment-related adverse events (relative risk: 0.50, 95% confidence interval: 0.42–0.60; P<0.001) compared with those undergoing chemotherapy.

Conclusions

Immune checkpoint inhibitors as second- or later-line therapy may improve overall response rate and overall survival but not all oncological outcomes for patients with locally advanced or metastatic esophageal squamous cell carcinoma. Patients treated with immune checkpoint inhibitors might experience fewer treatment-related adverse events of any grade, but specifically grade ≥3, compared with those treated with chemotherapy.

Prognostic impact of lymph node harvest for patients with node-negative esophageal squamous cell carcinoma: a large-scale multicenter study

Background

We examined the association between the number of resected lymph nodes and survival to determine the optimal lymphadenectomy for thoracic esophageal squamous cell carcinoma (ESCC) patients with negative lymph node.

Methods

We included 1,836 patients from Chinese three high-volumed hospitals with corresponding clinicopathological characters such as gender, age, tumor location, tumor grade and TNM stage of patients. The median follow-up of included patients was 45.7 months (range, 1.03-117.3 months). X-Tile plot was used to identify the lowest number of lymphadenectomy. The multivariate model's construction was in use of parameters with clinical significance for survival and a nomogram based on clinical variable with P<0.05 in Cox regression analysis. Both two models were validated using a cohort extracted from the Surveillance, Epidemiology, and End Results (SEER) 18 registries database between 1975 and 2016 (n=951).

Results

More lymphadenectomy numbers were significantly associated with better survival in patients both in training cohort [hazard ratio (HR) =0.980; 95% confidence interval (CI): 0.971-0.988; P<0.001] and validation cohort (HR =0.980; 95% CI: 0.968-0.991; P=0.001). Cut-off point analysis determined the lowest number of 9 for thoracic ESCC patients in N0 stage through training cohort (C-index: 0.623; sensitivity: 80.7%; 1 - specificity: 72.5%) when compared with 10 in validation cohort (C-index: 0.643; sensitivity: 78.2%; 1 - specificity: 63.0%). The cut-off points of 9 were examined in training cohort and validated in the divided cohort from validation cohort (all P<0.05). Meanwhile, nomograms for both cohorts were constructed and the calibration curves for both cohorts agreed well with the actual observations in terms of predicting 3- and 5-year survival, respectively.

Conclusions

Larger number for lymphadenectomy was associated with better survival in thoracic ESCC patients in N0 stage. Nine was what we got as the lowest number for lymphadenectomy in pN0 ESCC patients through this study, and our result should be confirmed further.

[Correlation between preoperative inflammatory biomarkers and postoperative pneumonia or long-term prognosis in patients with esophageal cancer after neoadjuvant therapy]

Objective: To examine the correlation between neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR) and neutrophil-monocyte ratio (NMR) for postoperative pneumonia or long-term overall survival in patients with esophageal cancer after neoadjuvant therapy. Methods: The clinical data of 137 patients, including 111 males and 26 females, with the age of (M(QR))61(10) years (range: 45 to 75 years), undergoing radical resection of esophageal cancer after neoadjuvant therapy admitted at Department of Thoracic Surgery, West China Hospital from January 2016 to May 2019 were analyzed retrospectively. The blood routine one or two days before surgery and the occurrence of pneumonia after surgery were collected via hospital information system. The absolute count of neutrophils, lymphocytes and monocytes was recorded, to calculate NLR, LMR and NMR. The survival of patients was recorded systematically via follow-up. In the first part, the influencing factors of postoperative inflammation were analyzed, to group the patients into two groups according to the occurrence of postoperative pneumonia. χ2 test, t-test or rank-sum test were conducted for inter-group comparison. In the second part, cutoff values of inflammatory biomarkers were obtained with the receiver operating characteristic (ROC) curve and grouped, with postoperative pneumonia as endpoint criteria. Independent factors correlated with postoperative pneumonia were determined through univariate and multivariate Logistic regression analysis. In the third part, the analysis on prognosis factors was carried on, with the survival as endpoint criteria. Cutoff values of inflammatory biomarkers were obtained with X-Tile software and grouped. The survival analysis was carried on with univariate and multivariate Cox proportional hazards regression model, and the Kaplan-Meier curve was drawn finally. The results of survival analysis were verified by Log-rank test. Results: Median follow-up time was 614 (299) days (range: 382 to 1 612 days). Cutoff values of NLR, LMR, and NMR obtained via the ROC curve were 3.0, 3.9, and 6.2, respectively. According to the multivariate Logistic regression analysis, NLR>3.0 (OR=2.740, 95% CI: 1.221 to 6.152, P=0.015) and LMR>3.9 (OR=0.140, 95% CI: 0.022 to 0.890, P=0.037) were independent prognosis factors for postoperative pneumonia in patients with esophageal cancer after neoadjuvant therapy. Cutoff values of NLR, LMR, and NMR obtained with X-Tile software were 3.3, 4.2, and 7.2, respectively. Through multivariate Cox proportional risk regression analysis, late tumor ypTNM staging (8th AJCC) (HR=2.087, 95% CI:1.079 to 4.038, P=0.029), poor pathologic response (HR=2.251, 95% CI: 1.117 to 4.538, P=0.023), and LMR>4.2 (HR=0.347, 95% CI: 0.127 to 0.946, P=0.039) could be independent prognosis factors for overall survival. Kaplan-Meier survival analysis indicated that the overall survival of patients with LMR ≤4.2 was worse (P=0.002), with the 1-year overall survival rate of 82.9%, and the 1-year overall survival rate of patients with LMR>4.2 was 94.6%. Conclusion: Preoperative LMR ≤3.9 and NLR>3.0 can be considered as independent prognosis factors for postoperative pneumonia, while LMR≤4.2 as one of independent prognosis factors for overall survival.

Prognostic Role of Nodal Skip Metastasis in Thoracic Esophageal Squamous Cell Carcinoma: A Large-Scale Multicenter Study

BACKGROUND

Nodal-skip metastasis (NSM) is found in esophageal squamous cell carcinoma (ESCC), but its prognostic role is controversial. This study aimed to investigate the prognostic value of NSM for thoracic ESCC patients.

METHODS

Categorization of NSM was according to the N groupings of Japan Esophagus Society (JES) staging system, which is dependent on tumor location. Using the Kaplan-Meier method and Cox-regression analysis, this study retrospectively analyzed the overall survival (OS) for 2325 ESCC patients after radical esophagectomy at three high-volume esophageal cancer centers. Predictive models also were constructed.

RESULTS

The overall NSM rate was 20% (229/1141): 37.4% in the in upper, 12.9% in the middle, and 22.2% in the lower thoracic ESCC. The patients with NSM always had a better prognosis than those without NSM. Furthermore, NSM was an independent prognostic factor for thoracic ESCC patients (hazard ratio [HR], 0.633; 95% confidence interval [CI], 0.499-0.803; P < 0.001). By integrating the prognostic values of NSM and N stage, the authors proposed the new N staging system. The categories defined by the new N staging system were more homogeneous in terms of OS than those defined by the current N system. Moreover, the new N system was shown to be an independent prognostic factor also for thoracic ESCC patients (HR, 1.607; 95% CI, 1.520-1.700; P < 0.001). Overall, the new N system had slightly better homogeneity, discriminatory ability, and monotonicity of gradient than the current N system.

CONCLUSIONS

This study emphasized the prognostic power of NSM and developed a modified node-staging system to improve the efficiency of the current International Union for Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) N staging system.

Pattern of subcarinal lymph node metastasis and dissection strategy for thoracic esophageal cancer

Background

This study aimed to assess the role of subcarinal lymph nodes in lymph node metastasis in thoracic esophageal squamous cell carcinoma (ESCC) and to investigate the adequate range of lymph node dissection during esophagectomy.

Methods

This study included 782 thoracic ESCC patients who underwent esophagectomy between July 2008 and December 2010. The metastatic rate of subcarinal lymph nodes and their influencing factors were investigated. The outcome of subcarinal lymph node dissection was assessed using the efficacy index (the incidence of metastasis to a lymph node station (%) multiplied by the 5-year survival rate (%) of patients with metastasis to that lymph node station and divided by 100). Additionally, postoperative complications were compared between the subcarinal lymph node resection and reservation groups.

Results

The metastatic rates of subcarinal lymph nodes in the upper, middle, and lower thoracic ESCC were 8.3% (4/48), 19.1% (79/414), and 16.2% (23/142), respectively (χ²=3.669, P>0.05) and in T1, T2, T3, and T4 tumors were 0% (0/71), 4% (4/100), 22.2% (85/383), and 34% (17/50), respectively (χ²=42.859, P<0.05). Tumor invasion and size were significantly correlated with metastasis. For upper thoracic ESCC with positive subcarinal lymph nodes, metastasis tendency was mainly to the lower mediastinum. In middle third esophageal cancer, after subcarinal lymph nodes were involved, metastasis to the lower mediastinal lymph nodes increased by nearly 50%, and bidirectional metastasis increased by nearly three times compared with that before involvement. For lower third cancer with positive subcarinal lymph nodes, metastasis tendency was mainly to the upper mediastinum. The postoperative complication rates in the resection and reservation groups were as follows: overall, 19% and 14.6%, respectively (P>0.05), and pulmonary, 10.3% and 7.3%, respectively (P>0.05). The efficacy indexes of lymph node dissection at the upper, middle, and lower third esophagus were 0%, 7.6%, and 27.5%, respectively.

Conclusions

Dissection of subcarinal lymph nodes, which does not increase postoperative complications, should be performed routinely in lower thoracic ESCC after submucosal invasion of tumor; meanwhile, tumors larger than 3cm should also result in subcarinal lymph node dissection in patients with a tumor located in the upper esophagus and T1-T2 ESCC.

A meta-analysis on surgery with or without postoperative radiotherapy to treat squamous cell esophageal carcinoma

BACKGROUND

Esophageal cancer (EC) is the sixth most common cause of cancer-related mortality in the world. Currently, surgery is the recommended treatment modality when possible. The outcomes of surgery alone are poor, and postoperative radiotherapy (PORT) has been used to patients with esophageal squamous cell carcinoma (ESCC) for years. However, the value of PORT for patients with ESCC after curative resection remains controversial. To assess the benefits and harms of postoperative radiotherapy compared with surgery alone for patients with ESCC we performed in this meta-analysis.

METHOD

A comprehensive electronic literature search was performed via the Cochrane Library, MEDLINE and EMBASE from January 1st, 1990 to October 1st, 2018 for relevant trials. The primary outcomes of interest are overall survival (OS) and disease-free survival (DFS). A meta-analysis was performed to calculate the hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Three randomized controlled trials (RCTs) and seven retrospective studies (RS) were included, for a total of 5640 patients with 1774 in the PORT group and 3866 in the surgery alone group respectively. Meta-analysis showed there were significant increases both for OS (HR 0.86, 95%CI 0.79-0.93, p = 0.0004) and DFS (HR 0.74, 95%CI 0.63-0.87, p = 0.004) for patients administered PORT compared with surgery alone. Regarding the postoperative recurrence, PORT can significantly reduce the local recurrence rate (OR 0.34, 95%CI 0.29-0.40, p < 0.00001), while it showed no difference in distant metastasis (OR 1.09, 95%CI 0.91-1.30, p = 0.37). Subgroup analysis demonstrated PORT can improve the OS for patients with positive lymph node (N+, HR 0.73, 95%CI 0.59-0.90, p < 0.00001), curative resection (R0 resection, HR 0.81, 95%CI 0.73-0.90, p < 0.0001) and T3 stage (HR 0.84, 95%CI 0.80-1.0, p = 0.05).

CONCLUSIONS

PORT improved the OS and DFS for patients with ESCC compared with surgery alone, and significantly reduced the local recurrence. PORT showed survival benefits for specific subgroups such as patients with positive lymph node, R0 resection margin and T3 stage.

Timing of surgery after neoadjuvant chemoradiotherapy affects oncologic outcomes in patients with esophageal cancer

BACKGROUND

The optimal time interval between neoadjuvant chemoradiotherapy (nCRT) and esophagectomy in esophageal cancer has not been defined.

AIM

To evaluate whether a prolonged time interval between the end of nCRT and surgery has an effect on survival outcome in esophageal cancer patients.

METHODS

We searched PubMed, Embase, Web of Science, the Cochrane Library, Wanfang and China National Knowledge Infrastructure databases for relevant articles published before November 16, 2019, to identify potential studies that evaluated the prognostic role of different time intervals between nCRT and surgery in esophageal cancer. The hazard ratios and 95% confidence intervals (95%CI) were merged to estimate the correlation between the time intervals and survival outcomes in esophageal cancer, esophageal squamous cell carcinoma and adenocarcinoma using fixed- and random-effect models.

RESULTS

This meta-analysis included 12621 patients from 16 studies. The results demonstrated that esophageal cancer patients with a prolonged time interval between the end of nCRT and surgery had significantly worse overall survival (OS) [hazard ratio (HR): 1.107, 95%CI: 1.014-1.208, P = 0.023] than those with a shorter time interval. Subgroup analysis showed that poor OS with a prolonged interval was observed based on both the sample size and HRs. There was also significant association between a prolonged time interval and decreased OS in Asian, but not Caucasian patients. In addition, a longer wait time indicated worse OS (HR: 1.385, 95%CI: 1.186-1.616, P < 0.001) in patients with adenocarcinoma.

CONCLUSION

A prolonged time interval from the completion of nCRT to surgery is associated with a significant decrease in OS. Thus, esophagectomy should be performed within 7-8 wk after nCRT.

Clinical and prognostic significance of preoperative lymphocyte-monocyte ratio, neutrophil-lymphocyte ratio and neutrophil-monocyte ratio on esophageal squamous cell carcinoma patients

Background

The interaction between tumor cells and inflammatory cells has not been systematically investigated in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to evaluate whether preoperative lymphocyte-monocyte ratio (LMR), neutrophil-lymphocyte ratio (NLR), and neutrophil-monocyte ratio (NMR) could predict the prognosis of ESCC patients undergoing esophagectomy.

Methods

A total of 1,883 patients with histologically diagnosed ESCC who underwent radical esophagectomy from May 2005 to May 2015 were retrospectively reviewed. Besides clinicopathological factors, “Survminer” package in R^® was applied to determine the optimal cut-off point for LMR, NLR and NMR. Meanwhile, we evaluated the prognostic value of LMR, NLR, and PLR using Kaplan-Meier curves and Cox regression models.

Results

The median follow-up was 28.77 months (range, 1.60–247.90 months). The optimal cut-off point of LMR, NLR and NMR is 3.83, 2.06 and 7.21, respectively. Kaplan-Meier survival analysis of patients with low preoperative LMR demonstrated a significant worse prognosis for 5-year OS (P<0.001) than those with high preoperative LMR. The high NLR cohort had lower 5-year OS (P<0.001). No significant difference with 5-year OS was found in NMR (P=0.405). On multivariate analysis, preoperative LMR (P=0.018; HR =0.786, 95% CI: 0.645, 0.959) and NLR (P=0.028; HR =1.247, 95% CI: 1.024, 1.519) were the independent prognostic factors in ESCC patients. Integrating LMR and NLR, we divided the ESCC patients in four groups according to their cut-off points and we found the patients in LMR ≥3.83 and NLR <2.06 group received the best prognosis while the prognosis of patients in LMR<3.83 and NLR ≥2.06 group was the worst. The difference was statistically significant.

Conclusions

Preoperative LMR and NLR better predicts cancer survival in patients with ESCC undergoing esophagectomy, especially under the circumstances of LMR ≥3.83 and NLR <2.06.

Clinical and prognostic effects of adjuvant therapy on less advanced esophageal squamous cell carcinoma patients

BACKGROUND

This study aimed to clarify whether adjuvant therapy is suitable for less advanced esophageal squamous cell carcinoma (ESCC) patients postoperatively.

METHODS

Data from 973 patients were collected. The prognosis and clinicopathological traits of these patients were calculated in both the TNM I and IIA stages. Meanwhile, 2 separate nomograms were applied in terms of the variables with a multivariate P value <0.05 in the Cox proportional hazard regression model.

RESULTS

There were 471 and 502 patients in the I and IIA stage respectively; among all enrolled patients, 641, 130, 73, and 129 patients were in the no-treatment, chemotherapy, radiotherapy, and chemoradiotherapy groups, respectively. Adjuvant therapy was drawn as the independent prognostic factors for stage I (P=0.026; HR =1.081, 95% CI: 1.093, 1.308) and IIA patients (P<0.001; HR =0.788, 95% CI: 0.693, 0.896). Radiotherapy consistently obtained the best prognosis for patients when compared with the other 3 groups in the I and IIA stage. Patients in I stage had the worst prognosis after receiving chemoradiotherapy, and still, the small survival benefits of chemoradiotherapy were seen in patients of IIA stage. Two separate nomograms for the I and IIA stage were constructed. The C-index was 0.665 (95% CI: 0.569, 0.761) in the I stage and 0.645 (95% CI: 0.567, 0.723) in the IIA stage. Meanwhile, the calibration curves for predicting 3-year and 5-year survival for I and IIA patients agreed well with the actual observations.

CONCLUSIONS

Among less advanced ESCC patients, adjuvant therapy was not only found to be an independent factor but also proved to be of importance in patient prognosis, and radiotherapy is recommended.

Prognostic value of preoperative weight loss-adjusted body mass index on survival after esophagectomy for esophageal squamous cell carcinoma

BACKGROUND

The impact of body mass index (BMI) on survival in patients with esophageal squamous cell carcinoma (ESCC) undergoing surgery remains unclear. Therefore, a definition of clinically significant BMI in patients with ESCC is needed.

AIM

To explore the impact of preoperative weight loss (PWL)-adjusted BMI on overall survival (OS) in patients undergoing surgery for ESCC.

METHODS

This retrospective study consisted of 1545 patients who underwent curative resection for ESCC at West China Hospital of Sichuan University between August 2005 and December 2011. The relationship between PWL-adjusted BMI and OS was examined, and a multivariate analysis was performed and adjusted for age, sex, TNM stage and adjuvant therapy.

RESULTS

Trends of poor survival were observed for patients with increasing PWL and decreasing BMI. Patients with BMI ≥ 20.0 kg/m² and PWL < 8.8% were classified into Group 1 with the longest median OS (45.3 mo). Patients with BMI < 20.0 kg/m² and PWL < 8.8% were classified into Group 2 with a median OS of 29.5 mo. Patients with BMI ≥ 20.0 kg/m² and PWL ≥ 8.8% (HR = 1.9, 95%CI: 1.5-2.5), and patients with BMI < 20.0 kg/m² and PWL ≥ 8.8% (HR = 2.0, 95%CI: 1.6-2.6), were combined into Group 3 with a median OS of 20.1 mo. Patients in the three groups were associated with significantly different OS (P < 0.05). In multivariate analysis, PWL-adjusted BMI, TNM stage and adjuvant therapy were identified as independent prognostic factors.

CONCLUSION

PWL-adjusted BMI has an independent prognostic impact on OS in patients with ESCC undergoing surgery. BMI might be an indicator for patients with PWL < 8.8% rather than ≥ 8.8%.

Prognostic significance and role of thoracic lymph node metastasis based on Chinese expert consensus in esophageal cancer

Background

The Chinese expert consensus on thoracic lymph node (LN) dissection in radical esophagectomy (Chinese Criteria, 2017 edition) was newly promoted. This study examined the prognostic significance and role of thoracic LN metastasis based on the Chinese Criteria for esophageal cancer.

Methods

Data of patients with thoracic esophageal squamous cell carcinoma (ESCC) who underwent curative esophagectomy in the West China Hospital from May 2005 to May 2015 were retrospectively analyzed. Patients' prognosis and clinicopathological features were compared to determine the role of Chinese Criteria and their relationship with Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) 8th TNM staging.

Results

Overall, 2,285 qualified patients were divided into the no (n=1,148), skip (n=156), local (n=665), and mediastinal (n=316) metastasis groups according to the Chinese Criteria. Significant prognostic differences occurred among the four groups in all the thoracic and lower mediastinal ESCC patients (both P<0.001). The Chinese Criteria grouping was an independent prognostic factor for all thoracic [P<0.001; hazard ratio (HR) =1.261, 95% confidence interval (CI): 1.103-1.441], upper (P<0.001; HR =1.391, 95% CI: 1.264-1.530), lower mediastinal thoracic ESCC patients (P<0.001; HR =1.312, 95% CI: 1.257-1.370) and all thoracic ESCC after adjuvant therapy (P<0.001; HR =1.303, 95% CI: 1.221-1.390). Significant prognostic differences among Chinese Criteria groups occurred with N1 (P=0.014) and N2 (P=0.018) stages only. Significant differences in survival among N stages were found in local (P<0.001) and mediastinal (P=0.009) metastasis groups.

Conclusions

Our study was the first to report the Chinese Criteria in measuring the degree of thoracic LN metastasis. Similar to N-stage, the Chinese Criteria were confirmed as an independent prognostic factor for thoracic ESCC. Further confirmation of our findings is warranted.

Risk factors for benign anastomotic stricture post-oesophagectomy: single-centre analysis of 702 oesophagectomies with squamous cell carcinoma

Background

Benign stricture formation after oesophagectomy makes a considerable impact on postoperative recovery, nutritional status and quality of life. Our aim was to investigate the incidence and risk factors for benign anastomotic stenosis post-oesophagectomy in a large series of patients.

Methods

We conducted a retrospective study of all patients undergoing oesophagectomy of oesophageal squamous cell carcinoma (ESCC) in our department from August 2012 to May 2013. Anastomotic stricture was identified clinically and radiologically. A total of 14 clinicopathological variables were assessed by univariate and multivariate logistic regression analyses.

Results

The study included 702 patients, and anastomotic stricture occurred in 62 patients (8.8%), which was significantly higher after cervical (20.8%) anastomosis than below (7.4%) or above (6.6%) aortic arch anastomosis. The anastomotic stricture rate was 31.8% in single-layer hand sewn (s-HS) anastomosis, 11.7% in circular stapled (CS) anastomosis, 10.4% in double-layer hand-sewn (d-HS) anastomosis and 1.9% in semi-mechanical (SM) anastomosis. The univariate analysis found that hypertension, surgical approach, anastomotic technique, anastomosis site, total number of removed lymph node and anastomotic leakage were associated with anastomotic stricture rate (P<0.05). Age, gender, body mass index (BMI), history of smoking or diabetes, the length of tumour, pT stage, pN stage and historical grading showed no statistically significant difference in the incidence of benign stenosis (P>0.05). On multivariate analysis, anastomosis site (P=0.006) and anastomotic technique (P<0.001) were independently associated with stricture risk.

Conclusions

Our study highlighted that patients with ESCC undergoing cervical anastomosis should be cautiously monitored postoperatively as a result of relative high stricture rate. SM technique is the preferred method of oesophago-gastric anastomosis due to a decreased stricture formation compared with other techniques.

The role of mitochondrial folate enzyme MTHFD1L in esophageal squamous cell carcinoma

OBJECTIVE

The lack of novel therapeutic targets poses the major challenge to prolong survival and improve the quality of life for esophageal squamous cell carcinoma (ESCC). Methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L) plays critical roles in folate cycle maintenance. However, little information is available concerning the role of MTHFD1L in cancer cells, and no studies have addressed such issues in esophageal cancer.

MATERIALS AND METHOD

Surgical cancer and adjacent normal esophageal tissues were obtained from patients with esophagectomy and esophagogastrostomy for ESCC. Western blot, immunohistochemistry and Quantitative RT-PCR were performed to evaluate protein and RNA expression levels of MTHFD1L. Knockdown of MTHFD1L expression was achieved by using short hairpin RNA. The effects of MTHFD1L silencing on ESCC cell proliferation and apoptosis were assessed by the MTT assay, Celigo assays, Annexin V FACS assay and Caspase-3/7 array in vitro.

RESULTS

Twenty-three paired cancer and adjacent normal esophageal tissues from patients with ESCC were included in this study. MTHFD1L protein and RNA expression levels were significantly upregulated in ESCC tissue as compared with normal tissue. High expression of MTHFD1 was also detected in two esophageal cancer cell lines (TE-1 and EC109). Knockdown of MTHFD1L expression inhibited the proliferation of TE-1 cells, and the apoptosis was distinctly increased following shMTHFD1L infection.

CONCLUSIONS

Our preliminary study highlighted for the first time that MTHFD1L might be involved in the development of ESCC, which may provide a new potential tumor-specific therapeutic targeting for anti-folate agents.

Missed diagnosis of esophageal leiomyoma leading to esophagectomy: a case report and review of literatures

Leiomyomas are the most common benign esophageal neoplasm. About half of them were smaller than 5 cm and asymptomatic with a stable size for many years. Esophageal leiomyomas that excess than 5 cm in size may develop as a consequence of giant one at rapid growth rate. This case report specifically describes a mid-aged woman who experienced a missed diagnosis of an esophageal leiomyoma over three years, which was covered by mediastinal thymolipoma and it subsequently developed as a giant tumor occupying the entire esophagus that makes the simple enucleation impossible. A surgical intervention of esophagectomy had to be performed to manage this entity.

Prognostic significance and role in TNM stage of tumor deposits in esophageal cancer

BACKGROUND

Tumor deposits (TDs) are now observed in esophageal cancer (EC), but the role of TDs is seldom elucidated. This study aimed to research the prognostic significance and the role of TDs in EC. The patients with primary EC, who had undergone curative esophagectomy in West China Hospital from May 2005 to May 2011 were retrospectively enrolled.

METHODS

The prognosis and clinicopathological traits were compared between tumor deposits positive (TDP) and tumor deposits negative (TDN) groups in all patients and TNM 0-IV stages respectively.

RESULTS

In our study, 1,044 patients were enrolled, with 948 (90.8%) in TDN group and 96 (9.2%) in TDP group. TDP group had significantly more advanced EC and worse prognosis (all P<0.001) than TDN group in all patients, TNM II stage and TNM III stage. The prognosis of TDP group in TNM II stage was significantly worse than TDN patients in TNM III stage (P<0.001), and the worst prognosis was always found in patients with at least one TD regardless of the number of metastatic lymph node is.

CONCLUSIONS

Patients in TDP subgroup had more advanced EC and worse prognosis than those in TDN subgroup. It might be more reasonable to be regarded as an indicator of stage migration in EC.

Three-field lymph node dissection in treating the esophageal cancer

There are many controversies in lymphadenectomy for thoracic esophageal cancer, and whether 3-field lymphadenectomy or 2-field lymphadenectomy is better have still been in doubt. The aim of this article is to review the role of the lymph node dissection by introducing the merits and demerits in 3-field lymphadenectomy, and the development in lymphadenectomy's selection, treatment and diagnosis. All the literatures related to esophageal lymphadenectomy and minimally invasive surgery (MIE) were searched in PubMed database and the cross references were added and reviewed to complete the reference list. Several researches elucidated that better overall survival (OS) in patients with esophageal cancer after 3-field lymphadenectomy had been reported worldwide, and 3-field lymphadenectomy is more suitable for treating esophageal cancer with cervical and/or upper mediastinal lymph nodes metastasis than 2-field lymphadenectomy regardless of the tumor's histology and location. Many approaches based on the characteristics of esophageal cancer lymph node metastasis are taken to improve the accuracy of 3-field lymphadenectomy and decrease the postoperative morbidity and mortality, while every approach needs further studies to demonstrate its feasibility. The benefits of the recently rapid-developed techniques performed in treating esophageal cancer: the MIE and the robotic-assisted thoracoscopic esophagectomy are illuminated as well, and both of them are technically safe and feasible for esophageal cancer, whereas further evaluations are still necessary.

First Report on the Occurrence of Cucumber mosaic virus on Fragaria ananassa in China

More than 20 viruses are known to infect strawberry (Fragaria ananassa), and a substantial number of these include new viruses identified since 2000 that can contribute to disease complexes (2). The most serious virus related losses in commercial strawberries are caused by aphid transmitted viruses (3,4,5). A survey was undertaken from 2012 to 2013 to investigate virus prevalence in commercial strawberries in rural areas of Hebei Province around Beijing, China, that were exhibiting virus symptoms. Visual observations revealed that the incidence of virus-like symptoms ranged from 30 to 50% of the plants and these symptoms included yellowing, leaf malformation, sometimes combined with severe stunting and deformed flowers or fruits. Leaf samples were tested for Strawberry vein banding virus (SVBV), Strawberry mottle virus (SMoV), Strawberry mild yellow edge virus (SMYEV), and Strawberry crinkle virus (SCV), which are the four most prevalent aphid-transmitted viruses in single or mixed infections (2). Testing was conducted by RT-PCR using total RNA extracted from fresh symptomatic strawberry leaves (3). SVBV was detected in 58 of 190 samples, but all of the samples tested negative for SMoV, SMYEV, and SCV. Aphids were present on many of the plants, so the samples were tested for Cucumber mosaic virus (CMV) because CMV is prevalent in Beijing gardens and farms, and recently had been shown to infect maize in China (5). This RT-PCR was carried out with the CMV primer pair CM420-F (5'-TGATTCTACCGTGTGGGTGA-3') and CM420-R (5'-CCGTAAGCTGGATGGACAAC-3') to amplify a portion of the capsid protein coding region and the conserved 3'non-translated regions of the genomic RNAs. This test revealed the presence of 43 CMV-positives out of 190 samples, and only 16 of these samples were co-infected with both SVBV and CMV. Samples infected with CMV only had leaf malformations and yellowing, while no CMV was found in symptomless samples. One of the amplified, CMV-specific DNA fragments was sequenced directly from the PCR product and showed 93.8% nucleotide sequence identity and 100% amino acid sequence identity to the CMV subgroup I (GenBank Accession No. D10538) (1). Subsequent ELISA tests for the CMV presence verified the RT-PCR results (Agdia, Elkhart, IN), and transmission electron microscopy observations revealed 28 nm spherical particles characteristic of CMV in strawberry samples tested positive for CMV. However, we were unable to detect either CMV or SVBV in 89 of the 169 samples from symptomatic plants, which suggested possible presence of the other pathogen(s). To the best of our knowledge, this is the first report of natural infections of CMV in strawberry plants. These data suggests that CMV is a potential threat to strawberry production. References: (1) M. Q. K. Andrew et al. Virus taxonomy: IXth Report of the ICTV, 970, Elsevier, 2012. (2) R. R. Martin and I. E. Tzanetakis. Plant Dis. 97:1358, 2013. (3) J. R. Thompson et al. J. Virol. Methods 111:85, 2003. (4) I. E. Tzanetakis et al. Plant Dis. 90:1343, 2006. (5) R. Wang et al. J. Phytopathol. 161: 880, 2013.

[Experimental study for repair of cranial defects with bone marrow stromal cells and modified alginate]

OBJECTIVE

The primary aim of this investigation was to determine whether expanded BMSCs in vitro mixed with modified alginate gelatin could repair critical defects in rats without the addition of exogenous growth or bone morphogenetic factors.

METHODS

Bone marrow stem cells from syngeneic rats cultured in vitro and mixed with modified alginate gel to paint the cranial critical size defect. A full-thickness cranial plate defect was created without damage of dura mater. Modified alginate gelatin with or without BMSCs were painted over the cranial defects. Animals being made cranial defect but received no implant served as sham-operated controls. Craniotomy defects were divided into three groups, which included defects left unpainted (group I, n=6), defects painted with modified alginate gelatin alone (group II, n=6), and defects painted with a modified alginate mixed with BMSCs (group III, n=6). A total of 18 implant experiments were carried out, with postsurgical radiographic and histological analysis completed at 12 week.

RESULTS

None of the implants exhibited extrusion or infection. Radiographs showed a likely increased calcification in group III, without finally new calcification in group I and in group II. Histology showed that group I and group II were featured by thinning of the bone at the edges of the defect margins with minimal bone growth inward and dense fibrous tissue with rudimentary alginate material spanning the intervenient gap. The results demonstrated that a great amount of new bone in growth took place in BMSCs-alginate group, stemming from cranial defect edges and proceeding inward.

CONCLUSION

Transplantation of syngeneic BMSCs with alginate gel can serve as an example of a cell-based treatment for skeletal reformation and would be especially useful for augmenting or regenerating bone in skeletal defects. So syngeneic BMSCs with alginate gel demonstrate a potential technique to regenerate a variety of skeletal defects that occur in different clinical scenaries.

[Expression of platelet derived growth factor receptor-beta in fibroblasts of keloid]

OBJECTIVE

To investigate the expression and distribution of platelet derived growth factor receptor-beta(PDGFR-beta) in normal skin and keloid and to discuss its biological function in keloid formation.

METHODS

1. To detect the expression and distribution of PDGFR-beta in normal skin and keloid tissue by immunohistochemistry; 2. To detect the receptor expression in vitro by Flow cytometry (FCM); 3. To detect the subcellular distribution of receptor by Laser confocal microscope.

RESULTS

1. Immunohistochemistry showed that normal skin and keloid tissue were almost the same in expression but different in distribution of PDGFR-beta; 2. There was more expression of PDGFR-beta in normal fibroblasts than that in keloid fibroblasts in vitro by FCM; 3. Laser confocal microscope revealed that the PDGFR-beta concentrated on the surface of cell membrane in keloid fibroblasts, but in normal skin fibroblasts, the receptors were coagulated on the nuclear membrane and intranucleus.

CONCLUSION

Compared with the fibroblasts in vivo, there was a difference of the PDGFR-beta expression in fibroblasts in vitro, more expression of PDGFR-beta in normal fibroblast than that in keloid fibroblast in vitro; and the subcellular distribution of PDGFR-beta was different in normal skin and keloid fibroblasts. The characteristics of the expression and distribution of PDGFR-beta in keloid may contribute to the formation of keloid.

[The experimental study on optimal cell density and formation time of tissue engineered autologous cartilage]

OBJECTIVE

This paper aims to investigate the suitable cell density and the best formation time of tissue engineered autologous cartilage and to provide theoretical basis and parameters for clinical application.

METHODS

The chondrocytes isolated from mini swines' ears were mixed with injectable biocompatible matrix (Pluronic), and the density of cell suspensions were 10, 20, 30, 40, 50, 60, 70 x 10(4)/ml. The chondrocyte-polymer constructs were subcutaneously injected into the abdomen of autologous swine. The specimens were observed grossly and histologically after 6 weeks, and investigated the suitable cell density. Then the chondrocyte-polymer constructs with suitable cell density were transplanted into the abdomen of autologous swine and evaluated grossly and histologically in 1, 3, 6, 9, 15 weeks after transplantation to investigate the best formation time of tissue engineered cartilage.

RESULTS

The experiments demonstrated that the tissue engineered autologous cartilage was similar to the natural cartilage on animals with normal immune system in histological characteristics. The optimal chondrocyte density is 50 x 10(6)/ml, and the proper harvest time is the sixth week.

CONCLUSION

With tissue engineering skills, we have identified the optimal chondrocyte density and the proper harvest time.

[Cultivation of cicatricial fibroblasts and kinetics of growth]

The fibroblasts from normal skin, hypertrophic scar and keloid were cultured in vitro and their growth property was compared. The results showed that there was similar density-dependent inhibition in these three strains, and there were no morphological differences among them. But, in normal skin, fibroblasts were parallelly arranged, showing "fingerprint" and marked polarization, while that in hypertrophic scar and keloid presented crisscross and overlapping with less polarization. All of three strains had same growth kinetics, i.e. the cell growth curve, DNA synthesis and mitosis index were similar during their logarithmic phase.