An Institutional Study on Thymomas and Thymic Carcinomas: Experience in 77 Patients

Abstract

Background: 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. Patients and Methods: 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. Results: 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. Conclusion: 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.

thoracic surgery - thymoma - thymic carcinoma - survival

References

• 1 Rosai J, Sobin L H. Histological typing of tumors of the thymus. World Health Organization. International Histological Classification of Tumors. Heidelberg; Springer 1999
• 2 Travis W D, Brambilla E, Müller-Hermelink H K, Harris C C. World Health Organization Classification of Tumors. Pathology and Genetics of Tumors of the Lung, Pleura, Thymus and Heart. Lyon; IARC Press 2004
• 3 Rieker R J, Hoegel J, Morresi-Hauf A. et al . Histologic classification of thymic epithelial tumors: comparison of established classification schemes.  Int J Cancer. 2002;  98 900-906
• 4 Kim D J, Yang W I, Choi S S, Kim K D, Chung K Y. Prognostic and clinical relevance of the World Health Organization schema for the classification of thymic epithelial tumors: a clinicopathologic study of 108 patients and literature review.  Chest. 2005;  127 755-761
• 5 Masaoka A, Monden Y, Nakahara K, Tanioka T. Follow-up study of thymomas with special reference to their clinical stages.  Cancer. 1981;  48 2485-2492
• 6 Giaccone G. Treatment of malignant thymoma.  Curr Opin Oncol. 2005;  17 140-146
• 7 Ganz P A, Haskell C M, Figlin R A, La Soto N, Siau J. Estimating the quality of life in a clinical trial of patients with metastatic lung cancer using the Karnofsky Performance Status and the Functional Living Index-Cancer.  Cancer. 1988;  61 849-856
• 8 Detterbeck F C, Parsons A M. Thymic tumors.  Ann Thorac Surg. 2004;  77 1860-1869
• 9 Bergh N P, Gatzinsky P, Larsson S, Lundin P, Ridell B. Tumors of the thymus and thymic region: I. Clinicopathological studies on thymomas.  Ann Thorac Surg. 1978;  25 91-98
• 10 Maggi G, Casadio C, Cavallo A, Cianci R, Molinatti M, Ruffini E. Thymoma: results of 241 operated cases.  Ann Thorac Surg. 1991;  51 152-156
• 11 Regnard J F, Magdeleinat P, Dromer C. et al . Prognostic factors and long-term results after thymoma resection: a series of 307 patients.  J Thorac Cardiovasc Surg. 1996;  112 376-384
• 12 Kondo K, Monden Y. Therapy for thymic epithelial tumors: a clinical study of 1320 patients from Japan.  Ann Thorac Surg. 2003;  76 878-884 884-875
• 13 Tseng Y L, Wang S T, Wu M H, Lin M Y, Lai W W, Cheng F F. Thymic carcinoma: involvement of great vessels indicates poor prognosis.  Ann Thorac Surg. 2003;  76 1041-1045
• 14 Hsu C P, Chen C Y, Chen C L. et al . Thymic carcinoma. Ten years' experience in twenty patients.  J Thorac Cardiovasc Surg. 1994;  107 615-620
• 15 Rea F, Sartori F, Loy M. et al . Chemotherapy and operation for invasive thymoma.  J Thorac Cardiovasc Surg. 1993;  106 543-549
• 16 Venuta F, Rendina E A, Longo F. et al . Long-term outcome after multimodality treatment for stage III thymic tumors.  Ann Thorac Surg. 2003;  76 1866-1872
• 17 Wright C D, Wain J C, Wong D R. et al . Predictors of recurrence in thymic tumors: importance of invasion, World Health Organization histology, and size.  J Thorac Cardiovasc Surg. 2005;  130 1413-1421
• 18 Rieker R J, Joos S, Mechtersheimer G. et al . COX‐2 upregulation in thymomas and thymic carcinomas.  Int J Cancer. 2006;  119 2063-2070
• 19 Wilkins Jr E W, Edmunds Jr L H, Castleman B. Cases of thymoma at the Massachusetts General Hospital.  J Thorac Cardiovasc Surg. 1966;  52 322-330
• 20 Wilkins K B, Sheikh E, Green R. et al . Clinical and pathologic predictors of survival in patients with thymoma.  Ann Surg. 1999;  230 562-572
• 21 Gripp S, Hilgers K, Wurm R, Schmitt G. Thymoma: prognostic factors and treatment outcomes.  Cancer. 1998;  83 1495-1503
• 22 Urgesi A, Monetti U, Rossi G, Ricardi U, Maggi G, Sannazzari G L. Aggressive treatment of intrathoracic recurrences of thymoma.  Radiother Oncol. 1992;  24 221-225
• 23 Mack M J, Scruggs G. Video-assisted thoracic surgery thymectomy for myasthenia gravis.  Chest Surg Clin N Am. 1998;  8 809-827 827-834
• 24 Cheng Y J, Kao E L, Chou S H. Videothoracoscopic resection of stage II thymoma: prospective comparison of the results between thoracoscopy and open methods.  Chest. 2005;  128 3010-3012

1 These authors contributed equally to the study.