Conditional Survival of Patients with Limited-Stage Small Cell Lung Cancer After Surgery: A National Real-World Cohort Study.

BACKGROUND: The prognosis of limited-stage small cell lung cancer (LS-SCLC) after surgery usually is estimated at diagnosis, but how the prognosis actually evolves over time for patients who survived for a predefined time is unknown. METHODS: Data on patients with a diagnosis of LS-SCLC after surgery between 2004 and 2015 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. The 5-year conditional cancer-specific survival (CCSS) and conditional overall survival (COS) were calculated. RESULTS: This study analyzed 997 patients (555 women, 55.7%) with a median age, of 67 years (interquartile range [IQR], 60-73 years). The 5-year CCSS and COS increased from 44.7% and 38.3%, respectively, at diagnosis to 83.7% and 67.9% at 5 years after diagnosis. Although there were large differences with different stages (stages I, II, and III) at diagnosis (respectively 59.5%, 28.4%; 28.1% for CCSS and 50.6%, 24.8%, and 23.6% for COS), the gap decreased with time, and the rates were similar after 5 years (respectively 85.0%, 80.3%, and 79.4% for CCSS; 65.6%, 56.9%, and 61.3% for COS). The 5-year conditional survival for the patients who received lobectomy was better than for those who received sublobectomy or pneumonectomy. Multivariable analyses showed that only age and resection type were independent predictors for CCSS and COS, respectively, throughout the period. CONCLUSION: Conditional survival estimates for LS-SCLC generally increased over time, with the most significant improvement in patients with advanced stage of disease. Resection type and old age represented extremely important determinants of prognosis after a lengthy event-free follow-up period.

Construction and validation of a risk-scoring model to predict lymph node metastasis in T1b-T2 esophageal cancer.

BACKGROUND: Lymph node status is an important factor in determining preoperative treatment strategies for stage T1b-T2 esophageal cancer (EC). Thus, the aim of this study was to investigate the risk factors for lymph node metastasis (LNM) in T1b-T2 EC and to establish and validate a risk-scoring model to guide the selection of optimal treatment options. METHODS: Patients who underwent upfront surgery for pT1b-T2 EC between January 2016 and December 2022 were analyzed. On the basis of the independent risk factors determined by multivariate logistic regression analysis, a risk-scoring model for the prediction of LNM was constructed and then validated. The area under the receiver operating characteristic curve (AUC) was used to assess the discriminant ability of the model. RESULTS: The incidence of LNM was 33.5% (214/638) in our cohort, 33.4% (169/506) in the primary cohort and 34.1% (45/132) in the validation cohort. Multivariate analysis confirmed that primary site, tumor grade, tumor size, depth, and lymphovascular invasion were independent risk factors for LNM (all P < 0.05), and patients were grouped based on these factors. A 7-point risk-scoring model based on these variables had good predictive accuracy in both the primary cohort (AUC, 0.749; 95% confidence interval 0.709-0.786) and the validation cohort (AUC, 0.738; 95% confidence interval 0.655-0.811). CONCLUSION: A novel risk-scoring model for lymph node metastasis was established to guide the optimal treatment of patients with T1b-T2 EC.

The association between histological subtypes and lymph node metastasis and prognosis in early esophageal cancer: a population-based study.

BACKGROUND: There is still a lack of high-level clinical evidence and uniform conclusions on whether there are differences in lymph node metastasis (LNM) and prognosis between early esophageal adenocarcinoma (EAC) and squamous cell carcinoma (ESCC). METHODS: Patients with surgically resected, histologically diagnosed, pT1 EAC or ESCC in the Surveillance, Epidemiology and End Results registries database from 2004 to 2015 were included. Multivariable logistic regression, Cox regression, multivariate competing risk model, and propensity score matching were used to analyze association the histology and LNM or prognosis. RESULTS: A total of 570 early esophageal cancer patients were included. The LNM rates were 13.8% and 15.1% for EAC and ESCC ( P  = 0.757), respectively. Multivariate logistic regression analysis showed no significant association between histological type and LNM (odds ratio [OR], 1.209; 95% CI, 0.538-2.715; P  = 0.646). Moreover, the prognosis of early EAC and ESCC was shown to be comparable in both multivariate Cox regression (hazard ratio [HR], 1.483; 95% CI, 0.699-3.150; P  = 0.305) and the multivariate competing risk model (subdistribution HR, 1.451; 95% CI, 0.628-3.354; P  = 0.383). After propensity score matching, there were no significant differences between early EAC and ESCC in terms of LNM (10.6% vs.18.2%, P  = 0.215), 5-year CSS (89.8% [95% CI, 81.0%-98.6%] vs. 79.1% [95% CI, 67.9%-90.3%], P  = 0.102) and 5-year cumulative incidence of CSS (10.2% [95% CI, 1.4%-19.0%] vs. 79.1% [95% CI, 9.7%-32.1%], P  = 0.124). CONCLUSION: The risk of LNM and prognosis of early ESCC and EAC are comparable, so the treatment choice for early esophageal cancer does not depend on the histologic type.

Adjuvant Therapy-Free Strategy for Stage IB to IIIA Non-Small-Cell Lung Cancer Patients After Radical Resection Based on Longitudinal Undetectable Molecular Residual Disease: Prospective, Multicenter, Single-Arm Study (CTONG 2201).

BACKGROUND: The utility of circulating tumor DNA to monitor molecular residual disease (MRD) has been clinically confirmed to predict disease recurrence in non-small cell lung cancer (NSCLC) patients after radical resection. Patients with longitudinal undetectable MRD show a favorable prognosis and might not benefit from adjuvant therapy. PATIENTS AND METHODS: The CTONG 2201 trial is a prospective, multicenter, single-arm study (ClinicalTrials.gov identifier, NCT05457049), designed to evaluate the hypothesis that no adjuvant therapy is needed for patients with longitudinal undetectable MRD. Pathologically confirmed stage IB-IIIA NSCLC patients who have undergone radical resection will be screened. Only patients with 2 consecutive rounds of undetectable MRD will be enrolled (first at days 3-10, second at days 30 ± 7 after surgery), and admitted for imaging and MRD monitoring every 3 months without adjuvant therapy. The primary endpoint is the 2-year disease-free survival rate for those with longitudinal undetectable MRD. The recruitment phase began in August 2022 and 180 patients will be enrolled. CONCLUSIONS: This prospective trial will contribute data to confirm the negative predictive value of MRD on adjuvant therapy for NSCLC patients. CLINICAL TRIAL REGISTRATION: NCT05457049 (CTONG 2201).

Right middle pulmonary vein classification by 3D-CT reconstruction and its clinical significance.

Background: A profound understanding of the type of right middle lobe (RML) vein return is crucial for thoracic surgeons to ensure safe anatomic lung resection. In this study, the type of venous return in the RML and its clinical significance were analyzed using the 3D computed tomography (3D-CT) reconstruction technique. Methods: This retrospective study analyzed the patients who underwent anatomical lobectomy or anatomical lung segment resection with preoperative 3D-CT reconstruction at the Department of Thoracic Oncology Surgery, Fujian Cancer Hospital from January 2020 to October 2022. The exclusion criteria were as follows: (I) blurred CT images and inadequate IQQA 3D reconstruction for clear visualization of bronchial and vascular subsegmental branches; (II) patients with a previous history of right middle lobectomy; (III) incomplete medical records. Results: This study included 608 eligible cases, 245 males (40.30%) and 363 females (59.70%), with an average age of 58.61 years. We identified four major types of RML venous return, including 407 cases (66.94%) of central vein type, 123 cases (20.23%) of isolated vein type, 11 cases (1.81%) of basal vein type, and 67 cases (11.02%) of combined vein type. Furthermore, the central venous type comprised four subtypes: 191 cases (27.3%) had one branch, 165 cases (27.14%) had two branches, 43 cases (7.07%) had three branches, and 8 cases (1.32%) had more than three branches. The combined venous type includes four subtypes: combination type A (n=37 cases, 6.09%), combination type B (n=7 cases, 1.15%), combination type C (n=21 cases, 3.45%), and combination type D (n=2 cases, 0.33%). Conclusions: Based on 3D-CT reconstruction, numerous types of venous return in the RML were found, highlighting the significance of 3D-CT reconstruction for thoracic surgeons. It plays a crucial role in understanding the type of RML venous return prior to surgery, providing invaluable information to ensure surgical safety and success.

A cross-sectional study: analysis of anatomical variation in the right upper lung intersegmental vein V2a based on a 3D reconstruction technique.

Background: This study aimed to summarize and analyze the anatomical structures of the right upper lung intersegmental vein V2a based on 3-dimensional (3D) reconstruction technology. Methods: We collected the enhanced computed tomography (CT) scans of 157 patients with pulmonary diseases, and reconstructed the right upper lung tissue structure through interactive qualitative and quantitative analysis (IQQA). According to the reconstruction results, the V2a of the right upper pulmonary intersegmental vein was returned to different veins for classification, and the subtypes were further subdivided according to the different vascular routes and the location of the pulmonary segmental bronchus. Results: Among 157 patients, there were 4 types of V2a according to the anatomical position of the veins. In type B (15 cases, 9.6%), V2a returned to the apical vein V1. In type C (2 cases, 1.3%), V2a did not exist, while in type D (1 case, 0.6%), V2a directly flowed into the right atrium. Type A is further divided into three subtypes (A1, A2, A3) according to the type of veins returned and the anatomical location of their confluence. In subtype A1 (110/139 cases, 79.1%), V2a returned to the posterior segment central vein. In subtype A2 (8/139 cases, 5.8%), V2a flowed from the B2 mediastinal surface down to the interlobular part of the posterior segmental vein. In subtype A3 (21/139 cases, 15.1%), V2a flowed between B1a and B2a and back to the central vein at the junction of the B2 and B3 bronchus. Type B is further divided into 3 subtypes (B1, B2, B3) according to the location of the apical posterior segmental bronchus. In B1 subtype (1/15 cases, 6.7%), V2a continued from the mediastinal surface of B1 back down to V1. In B2 subtype (7/15 cases, 46.7%), V2a continued from the medial side of the B1 lung back down to V1. In subtype B3 (7/15 cases, 46.7%), V2a flowed back into the central part of the posterior segmental vein. Conclusions: This study, supported by 3D reconstruction technology, preliminarily summarized the V2a typology and further refined the anatomical differences of each subtype.

Anatomical analysis of variations in the bronchus pattern of the left upper lobe using three-dimensional computed tomography angiography and bronchography.

Background: The number of sublobar resections performed is increasing, thoracic surgeons must be familiar with bronchus anatomy and preoperative planning plays an important role in predicting anatomical variations. However, there is few report showing anatomic variations of the left upper lobe (LUL) using three-dimensional computed tomography angiography and bronchography (3D-CTAB), and no in Chinese population. The present study aimed to use 3D-CTAB to describe variations of the pulmonary bronchus of LUL in Chinese population. Methods: In this retrospective study, we analyzed 3D-reconstruction from patients that performed lobectomy, segmentectomy or subsegmentectomy of the LUL in 2020 at Fujian Medical University Cancer Hospital's Department of Thoracic Surgery. Patients with previous LUL surgery or absence of 3D-reconstruction or without surgery were excluded. Results: One hundred and sixty-six patients met our criteria. Branching of the left upper bronchus was classified into bifurcated type (99.4%) or trifurcated type (0.06%). The left upper divisional bronchus (B 1+2+3) arise as bifurcated (65.65%) or trifurcated type (34.34%). Apicodorsalis bronchus (B 1+2) always originated as bifurcated type, while ventralis bronchus (B 3) was either bifurcated (94.45%) or trifurcated (5.55%). Lingular bronchus (B 4+5) was observed as bifurcated (96.38%) or trifurcated (3.62%) type. When analyzing sublobar divisions of bronchi a total of 14 subtypes were identified, 6 of them were found in the upper divisional bronchus. Conclusions: Bronchial anatomy of LUL is highly variable, especially in upper divisional bronchus. 3D-CTAB is a useful tool to identify variations in the bronchi pattern, we recommend preoperative planning for sublobar resection.

Analysis of anatomical variations of the lingular artery of the left upper lobe using 3D computed tomography angiography and bronchography.

BACKGROUND: Thoracic surgeons must be familiar with the anatomy of the pulmonary artery during segmentectomy and segmentectomy. But pulmonary arteries have numerous variations and aberrant branching patterns. The purpose of the present study was to analyze the anatomical variations and frequencies of the lingular artery of the left upper lobe (LUL) using 3D computed tomography angiography and bronchography (3D-CTAB). METHODS: We retrospectively studied 166 patients having undergone lobectomy or segmentectomy from January to December 2020 at Fujian Medical University Cancer Hospital's Department of Thoracic Surgery. All patients underwent 3D reconstruction using 3D-CTAB before surgery. RESULTS: The lingular segment was supplied by 1 artery in 45.18% of cases, 2 arteries in 46.39% of cases, and 3 arteries in 8.43% of cases. The branching patterns of the lingular artery included 119 (71.68%) cases with interlobar origin, 35 (21.08%) cases with interlobar and mediastinal origin, and 13 (7.83%) cases with mediastinal origin. The interlobar lingular artery include superior lingular artery (A4) and inferior lingular artery (A5). The interlobar lingular artery type was A4a, A4b, A5 in 7.23% of cases; A4 and A4b+5 in 3.01% of cases; and A4b and A4a+5 in 4.82% of cases. The mediastinal lingular artery was divided into the following 5 types: 'A4', 'A4b', 'A4b+5', 'A4b+5a', and 'A4+5'. The most common type was A4 (12.05%, 20/166) in 166 patients. The interlobar lingular artery had the following 5 patterns of variation: 'A4+5', 'A4, A5', 'A4a, A4b, A5', 'A4a, A4b+5', and 'A4b, A4a+5'. The single interlobar lingular artery (A4+5) was the most common type in 38.55% of cases. In 24.10% of cases, A5 came from A8 or A8+9. Besides In 8.43% of cases, the origin of A5 was close to A8 or A8+9. CONCLUSIONS: We identified the left various lingular artery branching patterns with 3D-CTAB in patients and defined the frequency of anatomic variations. 3D-CTAB is useful for finding these variations.

The role of endoscopic tumor length in resected esophageal squamous cell carcinoma: a retrospective study.

BACKGROUND: In esophageal squamous cell carcinoma (ESCC), tumor status is assessed on the basis of latitudinal invasion. Endoscopic tumor length (ETL) may represent the longitudinal scope of the primary tumor, and whether it affects tumor stage or prognosis is not entirely clear. In this study, we evaluated the role of ETL in patients with resected ESCC. METHODS: The relationships of ETL with pathological parameters (pT status and pN status) and overall survival (OS) were analyzed using data from patients with resected ESCC who were treated at Fujian Cancer Hospital between January 1997 and December 2013. Odds ratios (ORs) and hazard ratios (HRs) were fitted with locally weighted scatterplot smoothing, and the structural breakpoints for ETL were determined using the Chow test. RESULTS: A total of 721 patients with resected ESCC were enrolled. As the ETL increased in these patients, a rise in the risk of advanced pT status, nodal metastasis, and mortality was observed. Cutpoint analysis showed a breakpoint of 7.0 cm. A negative impact of ETL ≥7.0 cm was also found (adjusted HR, 1.335; 95% CI, 1.004-1.774). Seven independent prognostic factors, including sex, age, number of nodes dissected, T stage, N stage, tumor location, and ETL, were identified and entered into the nomogram. The calibration curves for 1-, 3-, and 5-year OS showed optimal agreement between nomogram prediction and actual observation (c-index: 0.688). CONCLUSIONS: Longer tumor length, with ETL ≥7.0 cm as the breakpoint, is a negative prognostic factor in patients with ESCC.

CircRNA_102179 promotes the proliferation, migration and invasion in non-small cell lung cancer cells by regulating miR-330-5p/HMGB3 axis.

Non-small cell lung cancer (NSCLC) accounting for 85 % of all lung cancer was one of the main causes of death worldwide. In this study, we investigated the role of circRNA_102179 in NSCLC development. The levels of circRNA_102179 in NSCLC tissues and cell lines were determined by quantitative real-time PCR assay (qRT-PCR). CCK8 and colony formation assays were applied to explore the effect of circRNA_102179 on the growth of NSCLC cells in vitro. Transwell assay was utilized to analyze the impact of circRNA_102179 on the migration and invasion of NSCLC cells. Target prediction and luciferase reporter assay were used to identify the interacting miRNA of circRNA_102179. The interaction among circRNA_102179/ miR-330-5p/HMGB3 was further validated by colony formation and Transwell invasion assays. Finally, the mouse xenograft NSCLC model was used to explore the role of circRNA_102179 in the tumor growth of NSCLC cells in vivo. CircRNA_102179 was overexpressed in NSCLC tissues and cells compared with normal lung tissues and human bronchial epithelial cells (HBEs). The down-regulation of circRNA_102179 markedly reduced the proliferation, migration, and invasion of NSCLC cells. Moreover, down-expression of circRNA_102179 significantly increased the level of miR-330-5p/HMGB3 in NSCLC cells. Further functional experiments indicated that over-expression of miR-330-5p reversed the inhibitory effect of circRNA_102179 on NSCLC cells growth, migration, and invasion. Our results reveal that circRNA_102179 facilitates the proliferation, migration, and invasion of NSCLC cell via modulating miR-330-5p/ HMGB3 axis in NSCLC cells.

[Perioperative nutrition support for esophageal cancer complicated with diabetes mellitus].

OBJECTIVE: To compare the efficacy between perioperative enteral and parenteral nutrition support for esophageal cancer patients complicated with diabetes mellitus. METHODS: Thirty esophageal cancer patients complicated with diabetes mellitus between September and November 2012 were prospectively enrolled in this trial. According to random number table, 30 cases were randomly divided into enteral group (n=15) and parenteral group (n=15). During the period between 3 days before operation and 8 days after operation, patients received enteral nutrition (AnSure) and parenteral nutrition support respectively. The daily dynamic monitoring of blood glucose was performed. Nutritional indexes (albumin and prealbumin) were evaluated 1-day before operation and 8-day after operation. Postoperative recovery time of gastrointestinal function and complications associated with nutritional support were observed. The cost of nutritional support was calculated. RESULTS: Patients in the two groups achieved satisfactory perioperative blood glucose control. Finger tip blood glucose was 5.0-9.0 mmol/L before meal, 7.0-10.0 mmol/L 2-hour after meal, and 4.0-8.0 mmol/L at 10 PM and 3 AM. No hypoglycemia (<3.5 mmol/L) was found in all the patients. The time to first flatus after surgery was (62.4±15.7) in the enteral group, significantly earlier than (90.8±22.4) h in the parenteral group (P<0.01). Postoperative nutritional indices and associated complications were not significantly different between two groups (all P>0.05). Cost in the enteral group was significantly lower than that in the parenteral group [(650.8±45.8) RMB vs. (3016.5±152.6) RMB, P<0.01]. CONCLUSION: Perioperative nutrition support can effectively control blood glucose and improve perioperative nutritional status simultaneously for esophageal cancer patients with diabetes mellitus. Compared with parenteral nutrition, enteral nutrition can accelerate the recovery of gastric bowel function and reduce the cost of nutritional support.

[Effect of PC cell-derived growth factor RNA interference on biological behavior of esophageal squamous carcinoma cells].

OBJECTIVE: To investigate the effect of PC cell-derived growth factor (PCDGF) RNA interference on esophageal squamous carcinoma cells Eca-109 in vitro. METHODS: The PCDGF-shRNA expression vector was transfected into the Eca-109 cells by liposome. After transfection, the mRNA and protein expressions of PCDGF were detected by RT-PCR and Western-blot respectively. Cell Counting Kit-8 (CCK-8) assay and Boyden chamber method were performed to measure the cell proliferation and invasion ability respectively. RESULTS: The expression levels of PCDGF mRNA and protein were both decreased in Eca-109 cells transfected with PCDGF-shRNA expression vector (transfection group). Twenty-four, 48 and 72 h after transfection, the cells proliferation in the transfection group was inhibited, and the inhibition rate was 20.4%, 21.1% and 20.9% respectively. The cell proliferation activity in the transfection group was significantly lower than that in the non-transfection group, liposome group and negative vector group (all P<0.05). The number of cell migration in the non-transfection group,negative vector group, liposome group and transfection group was 118.8±12.0, 100.8±9.0, 114.3±4.7, and 53.5±16.3 respectively. The differences were statistically significant between the transfection group and the other 3 groups (all P<0.05). CONCLUSIONS: PCDGF RNA interference can inhibit the proliferation and invasion abilities of esophageal squamous carcinoma cells in vitro. PCDGF gene may be the new target of gene therapy.

[Clinical application of minimally invasive esophagectomy for esophageal carcinoma].

OBJECTIVE: To investigate the feasibility and safety of minimally invasive esophagectomy (MIE) for esophageal carcinoma. METHODS: Clinical data of 298 esophageal carcinoma cases who were treated by MIE in the Fujian Provincial Cancer Hospital from June 2008 to April 2012 were retrospectively reviewed. RESULTS: All the patients underwent MIE successfully except one conversion to open surgery. The mean operative time was (242.3±58.7) min. The postoperative length of hospital stay was (17.4±9.8) d. The number of harvested lymph nodes of total, the mediastinum, the abdomen and the cervix was 27.5±12.2, 10.7±5.7, 13.3±7.8, and 7.7±8.1, respectively. Postoperative complication rate was 29.9%, including pneumonia (n=41), recurrent laryngeal nerve injury (n=25), anastomotic leak (n=9), wound infection (n=7), and others (n=7). After follow up of 2 to 47 months, 3 patients were found to develop anastomotic stricture. There were no recurrence, metastasis, or death. CONCLUSION: Minimally invasive esophagectomy is a safe, feasible, effective and minimally invasive surgical technique.

[Study of different enteral nutrition formulation treatment after esophagectomy].

OBJECTIVE: To compare the efficiency of different early enteral nutrition (EN) with Ensure, Nutrison, and Peptison in postoperative patients with esophageal carcinoma. METHODS: A total of 45 postoperative patients with esophageal carcinoma were randomly divided into three groups using random digit table: Ensure group (n=15), Nutrition group (n=15), and Peptison group (n=15). Enteral nutrition was given using nasogastric tube from the 2nd postoperative day for 8 days. Albumin and prealbumin were detected on the day before surgery and postoperative day 9 after fasting. The time to gastrointestinal tract function recovery, complications, and the cost of enteral nutrition were compared among the three groups. RESULTS: There were no significant differences in postoperative nutrition indices(albumin and prealbumin) and EN-related complications among the three groups(all P>0.05). The time to gastrointestinal tract function recovery in Ensure group [(52.4±15.7) h] and Nutrison group [(50.8±12.4) h] was less than that in Peptison group [(60.3±16.8) h] (P<0.05). The expense of Ensure group [(443.3±45.8) RMB] was obviously less than that of Nutrison group[(639.5±52.6) RMB] and Peptison group [(990.5±95.5) RMB](both P<0.01). CONCLUSIONS: Ensure, Nutrison and Peptison can be used for postoperative early enteral nutrition in patients with esophageal carcinoma, and the efficacy and complication are comparable. The cost of Ensure is the lowest.

[Analysis of lymph node metastases in early esophageal carcinoma and treatment regimens].

OBJECTIVE: To investigate the incidence of lymph node metastasis (LNM) in early esophageal carcinoma and the techniques of dissection. METHODS: Standard three-field dissection was performed in patients with small superficial esophageal carcinoma detected by endoscopy from 1993 - 2007. The lymph node metastases in different regions were identified by histopathology. The survival rate of the cases was analyzed. RESULTS: A total of 149 patients with early esophageal carcinoma were identified by postoperative pathological examination. The overall lymph node metastasis (LNM) rate was 22.8%, and the degree of LNM was 2.4% in all fields. Most lymph node metastases from upper thoracic esophageal carcinoma were found in cervical and the right upper mediastinal nodes. The LNM from middle thoracic esophageal carcinoma were approximately equal in the cervical, mediastinal, and abdominal lymph nodes, and abdominal lymph node metastasis predominated in lower thoracic esophageal carcinoma. The metastatic rate of LNM adjacent to the right recurrent laryngeaal nerve was the highest (44.1%). Significant differences were shown among the rates of LNM in relation to different macroscopic pattern, depth of invasion and differentiation of tumor (P < 0.01), but not to the longitudinal length of tumor (P > 0.05). The overall 5-year survival rate was 77.9%. It was 87.0% in patients without LNM, and 47.1% in those with LNM. CONCLUSION: Lymph node metastasis in early esophageal carcinoma is in a high frequency. Patients with tumor invasion into the mucosa or lamina propria but without lymph node metastasis may undergo a local operation such as endoscopic mucosectomy and have a good prognosis. Patients with tumor invasion into the muscularis mucosae or submucosa should be treated with radical surgery with three-field lymphadenectomy, especially, to dissect the lymph nodes adjacent to the recurrent laryngeal nerve.