Single-Centre 20-Year Experience with Surgical Treatment of Thymic Tumours

Background : Large single-centre institutional series on thymic tumours are rare. Complete resection remains the mainstay of successful treatment. Characteristics and survival were reviewed in all patients treated between 1993-2013. Methods : Hospital databases revealed 134 patients with pathologically-proven thymic tumour. Follow-up (median 63 months) was through patient notes and telephone contact with general practitioner. Results : Patients were classified in Masaoka-Koga stages : I: 50 (37%); IIa : 14 (10%); IIb : 14 (10%); III : 27 (20%); IVa : 19 (14%); IVb : 4 (3%); unknown : 6 (5%). According to WHO classification, pathological subtypes were A: 19 (14%); AB : 25 (19%); B1 : 21 (16%); B2 : 31 (23%); B3 : 15 (11%); thymic carcinoma : 23 (17%). Parathymic syndromes were diagnosed in 45 patients : myasthenia gravis (84%); pure red-cell aplasia (4%); hypogammaglobulinemia (2%); and others. 124 patients (93%) underwent surgery with complete resection in 104. (84%). Surgical approach was : sternotomy : 79; thoracotomy : 35; cervicotomy : 2; other/unknown : 8. In 73 patients (59%) no biopsy was taken prior to surgical resection, 25 were treated with induction chemotherapy, 36 received adjuvant radiotherapy. Hospital mortality was 0.81%. 35 patients died during follow-up (13 of tumour or treatment-related causes). Overall and recurrence-free survival at 5, 10, and 15 years were 86%; 64%; 47% and 67%; 49%; and 31%, respectively and were significantly (p < 0.01) different according to Masaoka-Koga stage. There was a significant association between WHO classification and Masaoka-Koga stages I-IIa-IIb versus III-IVa-IVb (p < 0.01). Conclusions : Operability and complete resectability of thymic tumours in our experience is high resulting in prolonged overall and recurrence-free survival. Masaoka-Koga stage is an important predictor for survival and shows a significant association with WHO classification.