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Objective:To observe the efficacy of drug combined with red-blue light irradiation, chemical peeling by glycolic acid and intense pulsed light (IPL) in the treatment of moderate acne vulgaris.Methods:A total of 187 patients with moderate acne vulgaris were divided into five groups. There were 59 males and 128 females, aged from 16 to 29 years (21.79±2.52). In group A, patients were treated with oral medicines; the patients were treated with oral medicines combined with red-blue light irradiation, chemical peeling by glycolic acid and IPL respectively in group B, group C and group D. In group E, patients were treated with oral medicines combined with chemical peeling by glycolic acid and IPL. The number of different types of skin lesions (comedoes, papules, pustules) were compared between before and after treatment in five groups. The clinical effect of five treatment groups was evaluated by comparing regression rates of different types of skin lesions and total skin lesions and treatment efficiency.Results:All the patients with moderate acne vulgaris were brought into this study. The regression rates of comedoes, papules and total skin lesions were (86.37±9.64)%, (94.25±9.79)% and (88.80±9.40)% respectively in group E, and significantly higher than that of other four groups ( P<0.05). The treatment efficiency of group E also were significantly higher than that of other four groups ( P<0.05). Then, the regression rates of comedoes (70.91±18.52) in group C was significantly higher than that of group A and group B ( P<0.05). The regression rates of papules (91.42±13.86) in group D was significantly higher than that of group A and group B ( P<0.05). Conclusions:Oral medicines combined with chemical peeling by glycolic acid and IPL has obvious clinical efficacy in treatment of patients with moderate acne vulgaris. Oral medicines combined with chemical peeling by glycolic acid can obviously improve comedoes, and oral medicines combined with IPL can obviously improve papules.
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Esophagectomy and lymph node dissection are the cornerstones for the treatment of esophageal cancer. Upper mediastinal lymph node dissection is of great value for accurate staging and improving the prognosis of patients. Lymph node dissection along the left recurrent laryngeal nerve is the most challenging procedures in esophageal surgery, and there has been no relevant consensus on the scope and boundary of lymph node dissection. In recent years, with the application of endoscopic technology, especially robotic surgery system in esophagectomy, and the introduction of the concept of superior mediastinal microdissection, the authors have proposed the border of lymph node dissection along the left recurrent laryngeal nerve, so as to achieve precise, radical and standardized dissection. Combined with their own experiences, the authors elaborate on the anatomic boundary, extent and technique of lymph node dissection along the left recurrent laryngeal nerve.
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Objective The surgical approaches and extent of lymph node dissection for Siewert type Ⅱ adenocarcinoma of the esophagogastric junction(AEG) are controversial.The present study was aimed to investigate the application of right thansthoracic Ivor-Lewis(IL),left transthoracic(LTT),and left thoracoabdominal(LTA) approach in Siewert type Ⅱ AEG.Methods The data of 196 patients with Siewert type Ⅱ AEG received surgical resection in our cancer center between January 2014 and April 2016 was retrospectively analyzed.Finally,136 patients met the inclusion criteria were enrolled in the study and divided into the IL(47 cases),LTT(51 cases),and LTA group(38 cases).Clinical and short-term treatment effects were compared among the three groups.Results The patients with weight loss,diabetes,and heart disease increased in the LTT group (P =0.054,P =0.075,and P =0.063,respectively).Operation time was significantly longest in the IL group (P =0.000),but the amount of bleeding and tumor size did not significantly differ among the three groups (P =0.176 and P =0.228,respectively).The IL group had the significantly longest proximal surgical margin (P =0.000) and most number of total (P =0.000) and thoracic lymph nodes(P =0.000) dissected.Both the IL and LTA groups had more abdominal lymph nodes dissected than the LTT group(P =0.000).In general,the IL and LTT group had the highest dissection rates of every station of thoracic (P ＜ 0.05) and lower mediastinal lymph nodes (P ＜ 0.05),respectively.The dissection rate of the paracardial,left gastric artery,and gastric lesser curvature lymph nodes did not differ significantly among the three groups(P ＞ 0.05),but the dissection rate of the hepatic artery,splenic artery,and celiac trunk lymph nodes was significantly highest in the IL group (P ＜0.05).Postoperative hospital stay,perioperative complications,and mortality did not differ significantly among the three groups(P ＞ 0.05).Conclusion Compared with the traditional left transthoracic approach,the Ivor-Lewis approach did not increase the perioperative mortality and complication rates in Siewert type Ⅱ AEG,but obtained satisfactory length of the proximal surgical margin,and was better than left transthoracic approach in thoracic and abdominal lymph node dissection.However,the advantages of Ivor-Lewis procedure requires further follow-up and validation through prospective randomized controlled trials.
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Objective To investigate the effect of the number of lymph nodes examined (NLNE) on the prognosis of esophageal squamous cell carcinoma (ESCC).Methods The retrospective case-control study was conducted.The clinicopathological date of 628 ESCC patients who underwent radical resection in the Tianjin Medical University Cancer Institute and Hospital from January 2005 to March 2013 was collected.Patients underwent radical resection of ESCC through right thorax.Observation indicators:(1) surgical and postoperative pathological examinations;(2) follow-up and survival situations;(3) effect of NLNE on the prognosis of ESCC;(4) factors analysis affecting prognosis of ESCC patients;(5) subgroup analysis.Follow-up using outpatient examination,telephone interview and mail was performed to detect postoperative survival up to February 2018.Measurement data with skewed distribution were described as M (range).Receiver operating characteristic (ROC) curve analysis was used to determine the appropriate cut-off of the NLNE.The survival curve and survival rate were respectively drawn and calculated by the Kaplan-Meier method,and the survival analysis was done by the log-rank test.Multivariate analysis was done by the Cox proportional hazard model.Results (1) Surgical and postoperative pathological examinations:472 and 156 patients underwent respectively Ivor-Lewis and Mckeown operations.There were 284 patients with tumor diameter ≤ 3.5 cm and 344 patients with tumor diameter ＞ 3.5 cm.The total NLNE was 11 139 for all of the 628 patients,with an average NLNE of 18 per case(range,2-78 per case) and a median NLNE of 16 per case.Of 628 patients,high-,moderate-and low-differentiated tumors were respectively detected in 48,469 and 111 patients;staging T0-1,T2,T3 and T4a of depth of tumor invasion in 30,119,260 and 219 patients;N0,N1,N2 and N3 of degree of lymph node metastasis in 349,173,69 and 37 patients;rN0,rN1,rN2 and rN3 of rate of lymph node metastasis in 349,184,54 and 41 patients.(2) Follow-up and survival situations:all the 628 patients were followed up for 3-144 months,with a median time of 36 months.The 1-,3-and 5-year survival rates were 82.4％,53.7％ and 41.3％,respectively.(3)Effect of NLNE on the prognosis of ESCC:ROC curve showed that the appropriate cut-off value of the NLNE was 16.Using NLNE =16 as a cut-off value,5-year survival rate was respectively 36.7％ in patients with NLNE ＜ 16 and 45.1％ in patients with NLNE ≥ 16,with a statistically significant difference in survival (x2 =9.527,P＜0.05).According to a median NLNE of 23,the patients with NLNE ≥ 16 were further divided into patients with 16 ≤ NLNE ≤ 23 and NLNE ＞ 23.Results showed that 5-year survival rate in patients with NLNE ＜ 16,16 ≤ NLNE ≤ 23 and NLNE ＞ 23 was respectively 36.7％,41.2％ and 50.3％,with a statistically significant difference in survival among them (x2 =10.588,P＜0.05),between patients with NLNE ＜ 16 and 16 ≤ NLNE ≤ 23 (x2 =4.419,P＜0.05).There was no statistically significant difference between patients with 16 ≤ NLNE ≤ 23 and NLNE ＞ 23 (x2 =1.413,P＞0.05).Five-year survival rate in patients with NLNE ≤ 23 and NLNE ＞23 was respectively 38.6％ and 50.3％,with a statisctically significant difference (x2 =5.885,P＜0.05).(4)Factors analysis affecting prognosis of ESCC patients:results of univariate analysis showed that age,smoking history,BMI,tumor diameter,NLNE,depth of tumor invasion,degree and rate of lymph node metastasis were related factors affecting the prognosis of ESCC patients (x2 =5.454,4.875,7.669,10.691,10.588,30.612,59.780,76.565,P＜0.05).Results of muhivariate analysis showed that age,tumor diameter,NLNE,depth of tumor invasion and rate of lymph node metastasis were independent factors affecting the prognosis of ESCC patients [HR=1.268,1.300,0.762,1.354,1.357,95％ confidence interval (CI):1.034-1.556,1.038-1.629,0.662-0.878,1.183-1.549,1.089-1.692,P＜0.05].(5) Subgroup analysis:among 279 patients with lymph node metastasis,5-year survival rate in patients with NLNE ＜ 16,16 ≤ NLNE ≤ 23 and NLNE ＞ 23 was respectively 23.7％,19.4％ and 39.5％,with a statistically significant difference among them (x2 =8.397,P＜0.05),between patients with 16≤ NLNE ≤ 23 and NLNE ＞ 23 (x2=5.425,P＜0.05).There was no statistically significant difference between patients with NLNE ＜ 16 and 16 ≤ NLNE ≤ 23 (x2 =0.389,P＞ 0.05).Five-year survival rate in patients with NLNE ≤ 23 and NLNE ＞ 23 was respectively 21.9％ and 39.5％,with a statisctically significant difference (x2=7.942,P＜ 0.05).Among 349 patients without lymph node metastasis,5-year survival rate in patients with NLNE ＜ 16,16 ≤ NLNE ≤ 23 and NLNE ＞ 23 was respectively 45.6％,60.3％ and 59.2％,with a statistically significant difference among them (x2 =9.755,P＜0.05) and between patients with NLNE ＜ 16 and 16 ≤ NLNE ≤ 23 (x2 =8.208,P＜0.05).There was no statistically significant difference between patients with 16 ≤ NLNE ≤ 23 and NLNE ＞ 23 (x2 =0.284,P＞0.05).Five-year survival rate in patients with NLNE ≤ 23 and NLNE ＞ 23 was respectively 51.1％ and 59.2％,with no statisctically significant difference (x2 =1.147,P＞ 0.05).Conclusions The NLNE is an independent factor affecting the prognosis of ESCC patients,and at least 16 to 23 lymph nodes should be dissected.For patients with lymph node metastasis,and more than 23 lymph nodes should be dissected.For patients without lymph node metastasis,more than 23 lymph nodes dissection cannot obviously improve the prognosis of patients.
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Objective@#To compare and evaluate the prognostic value of the 7th and 8th edition of The AJCC Esophageal Cancer Staging System for patients with stage Ⅱ and Ⅲ esophageal squamous cell carcinoma.@*Methods@#The clinical data of 328 esophageal cancer patients who received operation at Department of Esophageal Cancer, Tianjin Tumour Hospital from January 2006 to December 2010 were restrospectively analyzed. There were 63 female and 265 male patients. The mean age was 65 (range: 33 to 87) years. Univariate and multivariate analysis were performed to identify the prognosis factors.@*Results@#The five years overall survival rates among patients with stage Ⅱ and Ⅲ were both significantly different (χ2=87.035, 84.730, all P=0.000) according to the 7th and 8th editions of the TNM staging systems. The five years overall survival rate among patients with stage ⅡB and ⅢA were significantly different (39.6% vs 23.4%, P=0.001) according to the 7th edition of the esophageal cancer staging systems.According to the 8th edition of the esophageal cancer staging system, the 5 years survival rate of patients with stage ⅡA and ⅡB, ⅢB and Ⅳ was statistically significant (58.5% vs. 35.5%, P=0.040; 18.9% vs. 0, P=0.000). In multivariate analysis, tumor size, T staging, N staging and tumor differentiation (HR=1.592, 95%CI: 1.185 to 2.139, P=0.002; HR=1.519, 95% CI: 1.236 to 1.867, P=0.000; HR=1.647, 95% CI: 1.448 to 1.874, P=0.000; HR=1.404, 95% CI: 1.059 to 1.861, P=0.018) were the main independent prognosis factors affecting the prognosis of esophageal squamous cell carcinoma patients.@*Conclusions@#Both the 7th and the 8th editions of TNM staging systems are able to reflect the clinical prognosis of patients receiving radical resection of esophageal cancer, and the factors of tumor size, differentiaton, invasion depth and lymph node metastases are the independent predictors of prognosis. The 8th edition provides a more detailed and more reasonable for the staging of stage Ⅱ and Ⅲ for esophageal cancer patients than the 7th edition, and it is more accurate for the prognosis of patients with esophageal cancer after surgery.
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Objective@#To evaluate the lymph node metastasis (LNM) pattern and related prognostic factors for T1 esophageal cancer.@*Methods@#Clinical data of 143 cases of pT1 esophageal cancer patients (120 male and 23 female patients with median age of 60 years) who underwent esophagectomy and lymph node resection during January 2011 and July 2016 at the Department of Esophageal Cancer of Tianjin Medical University Cancer Institute and Hospital were reviewed, including 50 cases of T1a patients and 93 cases of T1b patients. The LNM pattern was analyzed and the prognostic factors related to LNM were assessed by χ2 test and Logistic regression analysis.@*Results@#Of 143 patients, 25 patients had LNM. The LNM rates were 17.5% for pT1 tumors, 16.0%(8/50) for pT1a tumors, and 22.6%(21/93) for T1b tumors. Of 25 patients with LNM, one patient had cervical metastasis, 15 patients with thoracic metastasis, and 17 patients with abdominal metastasis. The relatively highest LNM sites were laryngeal recurrent nerve (8 cases), left gastric artery (8 cases), right and left cardiac (6 cases) and thoracic paraesophageal (5 cases). Logistic regression analysis showed that the depth of tumor infiltration (OR=4.641, 95%CI: 1.279 to 16.836, P=0.020), tumor size (OR=5.301, 95%CI: 1.779 to 15.792, P=0.003), tumor location (OR=3.238, 95% CI: 1.248 to 8.401, P=0.016), and tumor differentiation (OR=5.301, 95%CI: 1.719 to 16.347, P=0.004) were independent prognostic factors related to LNM for T1 esophageal cancer. Tumor size (OR=4.117, 95% CI: 1.228 to 13.806, P=0.022) was an independent risk factor related to thoracic LNM, and the vessel invasion (OR=6.058, 95% CI: 1.228 to 29.876, P=0.027) and tumor location (OR=8.113, 95% CI: 1.785-36.872, P=0.007) were independent prognostic factors related to abdominal LNM.@*Conclusions@#T1 esophageal cancer has a relatively high LNM rate, and the depth of tumor infiltration, tumor size, tumor location and tumor differentiation are correlated with LNM. The LNM risk and extent must be considered comprehensively in decision-making of a better surgical treatment and lymph node resection strategy.
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Objective@#To compare the extent of lymphadenectomy and postoperative complications between Ivor-Lewis procedure and left sided thoracotomy in patients with Siewert type Ⅱ adenocarcinoma of the esophagogastric junction (AEG).@*Methods@#The clinical data of 101 patients with Siewert type Ⅱ EG who received surgical treatment between January 2014 and September 2015 in the Department of Esophageal Cancer, Tianjin Medical University Cancer Hospital were analyzed retrospectively. These patients were divided into Ivor-Lewis group (IL, n=38) and left- sided thoracotomy group (LT, n=63) according to the operation mode. The number and extent of dissected lymph nodes and postoperative complications were compared between the two groups.@*Results@#The surgical blood loss, length of postoperative stay, anastomotic leakage, pulmonary infection, respiratory failure and complications of incision of the two groups showed no significant differences (P>0.05 of all). The operation time of IL group was 200 min, significantly longer than the LT group (120 min, P<0.05). The number of resected lymph nodes in the IL and LT groups were (20±9) and (13±7), respectively, with a statistically significant difference (P<0.001). Significantly more thoracic lymph nodes (7±5) were harvested in the IL group than in the LT group (2±2, P<0.001), and the number of resected abdominal lymph nodes in the IL and LT groups were (13±8) and (11±7), with a non-significant difference (P=0.157). As regarding the lymph node dissection rate, the IL approach was obviously better than the LT approach in the following lymph node stations: superior mediastinal nodes, subcarinal nodes, left hilar nodes, right hilar nodes, middle thoracic paraesophageal nodes, lower thoracic paraesophageal nodes, lymph nodes along the common hepatic artery, and lymph nodes along the splenic artery(P<0.05 for all).@*Conclusions@#The Ivor-Lewis procedure achieves better thoracic and abdominal lymph node dissection, and does not cause more postoperative complications than the left-sided thoracotomy in patients with Siewert type Ⅱ AEG. However, these findings need to be confirmed by large-scale randomized clinical trial in the future.
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<p><b>OBJECTIVE</b>To compare the perioperative complications and the stress response between thoracoscopic esophagectomy and open esophagectomy in patients with esophageal cancer.</p><p><b>METHODS</b>Clinicopathologic data of 154 patients with esophageal cancer undergoing thoracoscopic esophagectomy (thoracoscope group) and 113 undergoing open procedure(open group) in the Tianjin Medical University Cancer Institute and Hospital from October 2012 to September 2014 were analyzed retrospectively. The incidence of perioperative complications and the change of stress response index in patients without complications were compared between two groups.</p><p><b>RESULTS</b>The total complication rate in thoracoscope and open group was 33.8% and 38.1%(P = 0.470) respectively. Compared with open group, incidence of ligation of thoracic duct(2.6% vs. 14.2%), recurrent laryngeal nerve paralysis (16.9% vs. 28.3%), chylothorax (0 vs. 4.4%), atelectasis (1.3% vs. 7.1%), pleural effusion (0.6% vs. 6.2%) and acute respiratory distress(0.6% vs. 6.2%) were obviously decreased in thoracoscope group(all P<0.05). No significant differences were observed in other complications (all P>0.05). Thirty-two cases and 24 cases without complication and with complete test data in thoracoscope and open group were selected for the detection of stress response index. There were no significant differences in white blood cell count, and the levels of cortisol, thyroxine (FT3 and FT4) and C-reactive protein between two groups at the same time points (before operation, 1, 3 and 6 days after operation) (all P>0.05).</p><p><b>CONCLUSION</b>Thoracoscopic esophagectomy has some obvious advantages associated with less pulmonary complications, lower morbidity of injury in thoracic duct and recurrent laryngeal nerve, while no significant difference of stress response is found in patients without complication between thoracoscope group and open group.</p>
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Humans , Esophageal Neoplasms , General Surgery , Esophagectomy , Ligation , Postoperative Complications , Retrospective Studies , ThoracoscopyABSTRACT
<p><b>OBJECTIVE</b>To study the impact of preoperative fasting plasma glucose(FPG) on postoperative morbidity and outcome following surgical resection of esophageal squamous cell carcinoma (ESCC), and to analyze the risk factor of postoperative complication in ESCC.</p><p><b>METHODS</b>Clinicopathological data of 314 ESCC patients undergoing esophagectomy in our center between January 2011 and December 2012 were retrospectively collected. Patients were divided into two groups according to their preoperative FBG: normal FPG group (FPG<6.1 mmol/L, 252 cases) and high FBG group (FPG≥6.1 mmol/L, 62 cases, including 14 diabetes cases). Clinicopathological data and postoperative morbidity were analyzed and compared between two groups. Multivariate logistic regression analysis was used to evaluate risk factors for postoperative complications.</p><p><b>RESULTS</b>There were 278 male and 36 female patients with a median age of 59 years (range 42-83 years). As compared to normal FPG group, high FBG group had higher ratio of female [22.6%(14/62) vs. 8.7%(22/252), P=0.000], older median age (66 years vs. 59 years, P=0.010), lower ratio of smoking and alcohol drinking [48.4%(30/62) vs. 73.8%(186/252), 38.7%(24/62) vs. 69.0%(174/252), both P=0.000], higher ratio of comorbid diabetes and hypertension [51.6%(32/62) vs. 15.1%(38/252), 16.1%(10/62) vs. 1.6%(4/252), both P=0.000]. Pathology results showed 206 patients in normal FPG group (81.7%, 206/252) were moderate-poor differentiation, which was obviously lower than 93.5%(58/62) in high FPG group(P=0.023). Patients of two groups completed their operations successfully. Perioperative overall complication morbidity was 24.2%(76/314), and the most common was lung lesions (24 cases of pneumonia, 10 cases of respiratory failure), then was anastomotic leakage (28 cases) and incision infection (18 cases). Differences in overall and other complication morbidity were not significant between two groups (all P>0.05). Multivariate logistic regression analysis revealed that operation time was an independent risk factor of postoperative complications (P=0.047), anastomosis site was an independent risk factor of anastomotic leakage (P=0.036), and FPG was not a risk factor of postoperative complications(respectively, P=0.683, P=0.836, P=0.784, P=0.637).</p><p><b>CONCLUSIONS</b>Preoperative control of FBG does not increase the postoperative complication morbidity. Shortening operation time and choosing appropriate surgical procedure are important to decrease postoperative complications.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Alcohol Drinking , Anastomotic Leak , Blood Glucose , Physiology , Carcinoma, Squamous Cell , General Surgery , Comorbidity , Diabetes Complications , Epidemiology , Diabetes Mellitus , Esophageal Neoplasms , General Surgery , Esophagectomy , Hypertension , Operative Time , Pneumonia , Epidemiology , Postoperative Complications , Epidemiology , Respiratory Insufficiency , Epidemiology , Retrospective Studies , Risk Factors , Smoking , Surgical Wound Infection , Epidemiology , Treatment OutcomeABSTRACT
Objective To analyze the differences in paraoperative morbidity and lymph node dissection between thoracoscopic esophagectomy and open procedure.Methods From October 2012 to April 2014,207 patients with esophageal cancer underwent surgery.125 patients underwent video-assisted esophagectomy,and 82 underwent open procedure.In the minimally invasive group,there were 109 thoracoscopic cases and 16 thoracolaparoscopic cases.Results There were significant differences between the thoracoscope group and the open group in atelectasis(0.8％ vs.7.3％,P ＜ 0.05),pleural effusion (0 vs.4.9％,P ＜ 0.05),acute respiratory distress (0 vs.6.1％,P ＜ 0.05),ligation of thoracic duct (3.2％ vs.15.9 ％,P ＜ 0.05),recurrent laryngeal nerve paralysis (19.2％ vs.32.9％,P ＜ 0.05),c hylothorax (0 vs.4.9％,P ＜ 0.05),number of lymphonode along the right recurrent laryngeal nerve lymphatic chains[1.91 ± 0.73 vs.1.12 ± 0.81,P ＜ 0.05)] and achievement ratio(97.6％ vs.89.0％,P ＜0.05) and number of lymphonode along the left recurrent laryngeal nerve lymphatic chains (0.93 ± 0.71 vs.1.76 ± 0.84,P ＜ 0.05) and achievement ratio(52％ vs.76.8％,P ＜ 0.05).No significant differences were observed in pneumonia,anastomotic leak,thoracic abscess,esophago-tracheal fistula,re-laparotomy,re-thoracotomy,wound infection,arrhythmia,cardia failure,renal failure,hepatic inadequacy,cerbral infarction,and mortality(P ＞ 0.05).There were also no significant differences in number of lymphonode and achievement ratio of periesophagel lymph nodes,subcarinal lymph nodes and hilar lymph nodes (all P ＞ 0.05).Conclusion The thoracoscopic esophagectomy has some obvious advantage associated with less pulmonary complications,lower injury of thoracic duct and recurrent laryngeal nerve,more lymphonode and higher achievement ratio along the right recurrent laryngeal nerve lymphatic chains.But it has still a larger space for improvement of lymphadenectomy along the left recurrent laryngeal nerve lymphatic chains.
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<p><b>BACKGROUND</b>To investigate the clinical characteristics of thoracic lymph node metastasis in lung cancer.</p><p><b>METHODS</b>Three hundred and eighteen patients with lung cancer underwent pneumonectomy or lobectomy and lymphadenectomy from Jan 2000 to Jan 2002.</p><p><b>RESULTS</b>A total of 1534 groups of lymph nodes were removed. Metastatic frequency of thoracic lymph nodes was 58.5% (186/318), in which N1 was 27.0% (86/318), N2 was 31.4% (100/318). There were higher frequencies of lymph node metastasis in 4, 7, 10, 11 regions around the root of lung. Among the skipping N2 metastasis (14.5%, 46/318), upper lobe cancer led to only upper mediastinal lymph node metastasis, however, lower or right middle lobe cancer caused both upper and lower mediastinal lymph node metastasis. Of the patients with swelling hilar and mediastinal lymph nodes reported by preoperative CT scan, only 48.2% were confirmed with lymph node metastasis by postoperative histopathology; while 22.4% of the patients with normal size lymph nodes had lymph node metastasis.</p><p><b>CONCLUSIONS</b>If there is no hilar and inferior carinal metastatic lymph node in patients with upper lobe cancer, the lower mediastinal lymph node dissection might not be necessary. But systematic mediastinal lymph node dissection should be performed in patients with lower lobe or right middle lobe cancer whether there is hilar or inferior carinal metastatic lymph node or not. The extent of lymph node dissection should not depend on the results of preoperative chest CT scan.</p>