[Analysis of the therapeutic effect of esophagectomy with extended 2-field lymph node dissection for esophageal carcinoma].

OBJECTIVE: To summarize the surgical effect and clinical application value of esophagectomy with extended 2-field lymph node dissection for patients with esophageal carcinoma. METHODS: From June 1987 to December 2008, 1690 patients with esophageal cancer underwent esophagectomy with extended 2-field (thoracic and abdominal) dissection of lymph nodes. Patients with the middle and lower thoracic esophageal cancer underwent Ivor-Lewis esophagectomy, and patients with upper thoracic esophageal cancer underwent Akiyama esophagectomy. 2-field (thoracic and abdominal) lymph node metastases information and the 1, 3, 5, 10-year survival rates were analyzed retrospectively. RESULTS: Lymph node metastases were found in 713 patients. The lymph node metastases rate was 42.2% (713/1690).Thoracic lymph node metastasis rate was 39.3% (665/1690), among which in the right pleural apical para-tracheal triangle was 20.7% (349/1690), in the posterior upper mediastinum was 26.3% (444/1690), in the lower mediastinum was 18.2% (307/1690). Abdominal lymph node metastasis rate was 20.1% (339/1690). THE Postoperative complication rate was 16.4% (278/1690), among which the pulmonary complication rate ranking the first, was 43.6% (136/312). The operative mortality rate was 0.2%. The 1-year, 3-year, 5-year and 10-year survival rates were 88.2% (1388/1574), 63.5% (868/1367), 54.8% (705/1287) and 30.8% (232/754), respectively. The 5-year survival rate in patients without lymph node metastasis was 76.2% (448/588), but that in patients with lymph node metastases was 36.8% (257/669). CONCLUSION: The results of this study demonstrated that Ivor-Lewis and Akiyama esophagectomy with two-field lymph node dissection exposes the operation fields clearly and make radical lymphadenectomy thoroughly, especially the lymph nodes in the posterior upper mediastinum around the recurrent laryngeal nerve and in the right pleural apical para-tracheal triangle. It is essential that patients with esophageal carcinoma with lymph node metastases should undergo esophagectomy with extended 2-field dissection of lymph nodes. This can elevate the postoperative 5-year survival rate remarkably.

[Correlation of aberrant methylation of MGMT gene to MTHFR C677T genetic polymorphisms in esophageal squamous cell carcinoma].

BACKGROUND & OBJECTIVE: As one of the principal causes of gene inactivation, aberrant hypermethylation in the promoter of cancer-related genes has attracted more and more attention. However, such studies on esophageal cancer are still limited. This study was to investigate the association between aberrant hypermethylation of MGMT gene and clinical characteristics as well as MTHFR C677T genetic polymorphisms in esophageal squamous cell carcinoma in a Chinese population. METHODS: A molecular epidemiologic study was conducted at Yangzhong County, Jiangsu Province of China, on histologically confirmed esophageal squamous cell carcinoma patients who were operated in the People's Hospital of Yangzhong County between January 2005 and March 2006. Peripheral blood samples, esophageal cancer tissues and paracancerous normal tissues were collected. Methylation-specific polymerase chain reaction(MSP) was used to detect the CpG island methylation status of MGMT gene. Restrictive fragment length polymorphism (RFLP) technique was used to test polymorphisms of folate metabolism enzyme gene MTHFR. The association between methylation status of MGMT gene and clinical characteristics as well as MTHFR C677T polymorphisms were analyzed. RESULTS: Among 125 esophageal squamous cell carcinoma patients, the aberrant hypermethylation rate of MGMT gene was 27.2% in cancer tissues and 11.2% in paracancerous normal tissues. No hypermethylation was found in normal esophageal tissues from 10 healthy adult subjects. Methylation rate of MGMT gene in cancer tissues was significantly higher in the patients with lymph node metastasis than in those without lymph node metastasis (37.3% vs. 18.2%, P=0.017). No association was found between aberrant DNA methylation and selected factors including sex, age, tobacco smoking, alcohol drinking and green tea drinking. After adjusting by potential confounders, variant allele of MTHFR C677T was found to be associated with hypermethylation of MGMT gene. Compared with wild type CC, the odds ratio was 3.34 (95% CI: 1.07-10.39) for CT and 3.83 (95% CI: 1.13-12.94) for TT. CONCLUSION: Aberrant CpG island hypermethylation of MGMT gene is closely related with the genesis and progression of esophageal squamous cell carcinoma.

Diet habits, alcohol drinking, tobacco smoking, green tea drinking, and the risk of esophageal squamous cell carcinoma in the Chinese population.

OBJECTIVE: This study aims to investigate the risk of esophageal squamous cell carcinoma in relation to exogenous factors in a rural area of China with a high incidence of esophageal squamous cell carcinoma. METHODS: A population-based case-control study was conducted in Yangzhong County, Jiangsu Province, China, with 355 histologically confirmed esophageal squamous cell carcinoma cases recruited between 1 January 2004 and 28 February 2006 and 408 controls matched by sex and age, randomly selected from the local population. RESULTS: Stratified logistic regression analysis by sex revealed that hot-temperature food items, pork braised in brown sauce and old stocked rice intake could increase the risk of esophageal squamous cell carcinoma with odds ratio of 2.127 (95% confidence interval: 1.394-3.245), 2.059 (95% confidence interval: 1.417-2.993) and 9.059 (95% confidence interval: 5.930-13.840), respectively, in men and 3.048 (95% confidence interval: 1.733-5.364), 1.914 (95% confidence interval: 1.159-3.162) and 14.532 (95% confidence interval: 7.816-27.019), respectively, in women, whereas diet high in salt and chili, tobacco smoking and alcohol drinking only showed possible risk effects in men with odds ratio 2.338 (95% confidence interval: 1.568-3.485), 3.378 (95% confidence interval: 2.117-5.389), 1.976 (95% confidence interval: 1.337-2.921) and 2.197 (95% confidence interval: 1.510-3.195), respectively. Green tea drinking showed a protective effect in women (odds ratio=0.257; 95% confidence interval: 0.070-0.941). CONCLUSIONS: Findings from this study provided evidence that dietary habits, tobacco-smoking and alcohol drinking contribute to the etiology of esophageal squamous cell carcinoma. A healthy dietary habit, with smoking cessation and alcohol controlling is of a great importance in the prevention of esophageal cancer.

[Right para-tracheal triangle lymphadenectomy for esophageal carcinoma].

OBJECTIVE: To investigate the incidence of lymph node metastasis (LNM) in the right para-tracheal triangle (RPT) of esophageal carcinoma patients and the technique of dissection. METHODS: On the top of double mediastinal and abdominal lymphadenectomy, 333 esophageal carcinoma patients received RPT lymphadenectomy through the right pleural apical approach from 1990 to 2001. RESULTS: In these 333 patients, the lymph node metastasis (LNM) rate in the RPT was 36.40%. A total of 457 nodes among 2 159 nodes removed gave a metastasis degree of 24.96%. The LNM rates in RPT for cervical, upper third, middle third, and lower third segments of esophagus were 66.67%, 45.45%, 34.19% and 15.79% (P < 0.05), while their respective metastasis degrees were 44.44%, 27.04%, 24.32% and 18.92% (P > 0.05). The frequency of positive nodes in the RPT for PTI, PT1, PT2, PT3 and PT4 was 0, 17.24%, 28.7%, 45.16% and 53.57%, while those of metastasis degree were 0, 8.77%, 17.62%, 33% and 41.17% (P < 0.01). The frequency of LNM in the RPT in papillary, erosive, patch-like and covert type of early tumor was 40%, 3.85%, 0 and 0 (P < 0.05), while those of the metastasis degree were 29.41%, 1.82%, 0 and 0 (P < 0.01). Higher rate of LNM in progressive stenotic esophageal carcinoma was observed compared with those of the other gross types (56.52%, P < 0.05), so was the degree (P < 0.01). The frequency of LNM in the RPT for mono-focal and multi-focal tumor was 34.98% and 70% without significant difference (P > 0.05), while the degree was 24.29% and 53.33% (P < 0.05). Postoperative complications were: leak (0.6%), and recurrent laryngeal nerve injury (1.2%). No injury of vein or infra-clavicular artery, tracheal damage or mortality occurred. CONCLUSION: 1. The lymph node metastasis from esophageal carcinoma has a tendency of wide spread and right para-tracheal triangle is an important region to be doomed. 2. With location, depth of tumor invasion and differentiation of tumor as major factors affecting LNM of esophageal carcinoma, dissection of this region should be paid more emphasis. 3. In early lesions, higher frequency of LNM in the RPT is found in papillary and erosive lesions than in the other macroscopic types. 4. Exposing the RPT, lymph node by dissection through a right pleural apical approach is very important and significant.