An institutional study on thymomas and thymic carcinomas: experience in 77 patients

Thymomas and thymic carcinomas are rare tumors of the anterior mediastinum. A WHO classification was introduced in 1999, which has been updated in 2004. Meanwhile, several retrospective studies have been carried out which have shown the prognostic significance of this classification together with Masaoka's staging system and the extent of surgery.

Between 1983 and 2000, 77 patients (37 male, 40 female) underwent resection of thymomas and thymic carcinomas in our institution. Complete resection was achieved in 57 patients. The median follow-up was 72.6 months.

The overall 5-year survival rate was 71.4 %. The factors "histology" and "extent of resection" had the most important impact on survival. However, even among the patients with complete resection, 12 of them suffered a relapse. Among this patient group, the most important factors for disease-free survival were "tumor stage" and "histology". Patients with an incomplete resection had a 5-year survival rate of only 29 % in spite of adjuvant radiation and/or chemotherapy. Due to the high rate of relapse, the poor survival rate found in incompletely resected patients as well as the failure of classical chemotherapy regimens, especially in type B2 and type B3 thymomas and thymic carcinomas, the search for new chemotherapeutic schemes is mandatory.

Our study shows that there are still encouraging therapeutic options for thymomas and thymic carinomas. Type B2, type B3 thymomas and thymic carcinomas have worse outcomes in spite of adjuvant chemo- and radiotherapies. Especially in patients with incomplete surgical resection the outcome remains poor.