Single-centre 20-year experience with surgical treatment of thymic tumours

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.

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.

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).

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.