Siewert classification, clinicopathological characteristics and prognostic analysis of adenocarcinoma of esophagogastric junction in 303 patients

Abstract

Objective To analyze the clinicopathological characteristics of adenocarcinoma of esophagogastric junction (AEG) according to Siewert classification and explore the prognostic factors of patients with AEG in different Siewert classifications after radical resection. Methods The retrospective case-control study was conducted. The clinicopathological data of 303 patients with AEG who were admitted to the Tianjin Medical University Cancer Hospital between December 2002 and September 2011 were collected. Among the 303 patients, 14, 172 and 117 patients were classified as with Siewert type Ⅰ, type Ⅱ and type Ⅲ AEG, respectively. Observation indicators included: (1) comparison of clinicopathological characteristics in different Siewert classification of AEG: gender, age, body mass index (BMI), tumor diameter, Borrmann classification, T stage, N stage, TNM stage and soft tissue invasion. (2) Follow-up: median survival time and 5-year survival rate. (3) Prognostic factors analysis in different Siewert classifications after radical resection of AEG: gender, age, tumor diameter, Borrmann classification, T stage, N stage, TNM stage, soft tissue invasion, surgical approach, number of lymph node dissected and postoperative adjuvant chemotherapy. Follow-up using telephone interview was performed to detect the survival of patients up to July 2016. Comparison of count data was analyzed using the chi-square test. The survival rate was calculated using the Kaplan-Meier method, and the survival analysis was done using the Log-rank test. The prognostic factors analysis was done using the COX regression model. Results (1) Comparison of clinicopathological characteristics in different Siewert classifications of AEG: number of patients with AEG in Siewert type Ⅰ, type Ⅱ and type Ⅲ were respectively 9, 57, 49 with age≤60 years, 5, 115, 68 with age>60 years, 11, 75, 49 with BMI≤22.7 kg/m2, 3, 97, 68 with BMI>22.7 kg/m2, 4, 68, 30 with tumor diameter≤4.0 cm, 10, 104, 87 with tumor diameter>4.0 cm, 0, 7, 0 with T1 stage, 2, 13, 4 with T2 stage, 0, 12, 6 with T3 stage, 12, 140, 107 with T4 stage, 1, 17, 2 with stage Ⅰ of TNM stage, 2, 45, 34 with stage Ⅱ of TNM stage and 11, 110, 81 with stage Ⅲ of TNM stage, with significant differences in above indicators among the patients with AEG in Siewert type Ⅰ, type Ⅱ and type Ⅲ (χ2=6.581, 6.959, 6.190, 14.136, 10.298, P 0.05). (3) Prognostic factors analysis of AEG in Siewert type Ⅱ after radical resection: results of univariate analysis showed that tumor diameter, N stage, TNM stage and soft tissue invasion were related factors affecting prognosis of patients with AEG in Siewert type Ⅱ after radical resection [HR=1.930, 2.539, 2.052, 1.980, 95% confidence interval (CI): 1.189-3.134, 1.231-3.589, 1.325-3.176, 1.173-3.343, P<0.05]. Results of multivariate analysis showed that N stage was an independent factor affecting prognosis of patients with AEG in Siewert type Ⅱ after radical resection (RR=1.483, 95%CI: 1.185-1.857, P<0.05). (4) Prognostic factors analysis of AEG in Siewert type Ⅲ after radical resection: results of univariate analysis showed that N stage, TNM stage, soft tissue invasion, surgical approach and postoperative adjuvant chemotherapy were related factors affecting prognosis of patients with AEG in Siewert type Ⅲ after radical resection (HR=1.445, 2.328, 2.549, 0.571, 0.562, 95%CI: 1.135-1.839, 1.190-4.554, 1.410-4.609, 0.328-0.993, 0.312-1.010, P<0.05). Results of multivariate analysis showed that N stage and soft tissue invasion were independent factors affecting prognosis of patients with AEG in Siewert type Ⅲ after radical resection (RR=1.456, 2.008, 95%CI: 0.976-2.172, 1.084-3.721, P<0.05). Conclusions Patients with AEG in different Siewert classifications have the different clinicopathological characteristics, and AEG in Siewert type Ⅱ presents better biological behavior. N stage is an independent factor affecting prognosis of patients with AEG in Siewert type Ⅱ after radical resection. N stage and soft tissues invasion are independent factors affecting prognosis of patients with AEG in Siewert type Ⅲ after radical resection. Key words: Esophagogastric junction neoplasms, adenocarcinoma; Radical resection; Siewert classification; Prognosis