[Prognostic factors for thymic epithelial tumor: a retrospective study of 137 cases]

To analyze the clinic and pathologic data of thymic epithelial tumor (TET) and to explore its prognostic factors.

From June 1997 to September 2007, 137 patients with TET were surgically treated in our hospital. The data included age, gender, symptoms, histological type, stage and grade, pathological findings, and operation reports. The patients were followed up by telephones and mails. The patients were divided into Masaoka I/II group and III/IV group, and WHO A/AB/B1 group and B2/B3/C group. Kaplan-Meier method, log-rank test, and COX regression model were used to analyze the prognostic factors for TET.

Among the 137 patients, 124 (90.5%) received complete resection, 9 (6.6%) incomplete resection, and 4 (2.9%) surgical biopsy. The rate of complete resection was significantly higher in Masaoka stages I/II than that in stages III/IV (P<0.001). The overall 5-year and 10-year survival rate was 71.4å and 50.1å, respectively. Patients in stage I/II had better long-term survival than those in stage III/IV (P<0.001). According to WHO histological classification, the 5-year and 10-year survival rate in patients with Type A/AB/B1 TET was significantly higher than that in patients with Type B2/B3/C TET (P<0.001). The 5-year and 10-year survival rate in patients with complete resection was significantly higher than that in patients with incomplete resection and biopsy (P<0.001).Cox regression analysis showed that the prognosis of patients with TET was related to Masaoka stage, WHO histological classification, extent of resection, and age at operation.

Masaoka stage, WHO histological classification, extent of resection, and age at operation are important prognostic factors in patients with TET.