Background: This study was performed to investigate the clinical factors, tumor characteristics, treatment approach, and prognosis of patients with Stage IV thymic carcinoma (WHO type C).
Methods: The records of 20 patients with histologically confirmed thymic carcinoma treated between 1988 and 2002 at the Division of Oncology at Taipei Veterans General Hospital were reviewed.
Results: Therapy consisted of surgical debulking, adjuvant radiotherapy, and chemotherapy in six patients (30%), surgical debulking with adjuvant chemotherapy in two patients (10%), surgical debulking with adjuvant radiotherapy in one patient (5%), radiotherapy with adjuvant chemotherapy in eight patients (40%), and chemotherapy alone in three patients (15%). After a median follow-up of 22 months (range, 5-72 months), three patients (15%) were alive. Eighteen patients (90%) experienced disease recurrence after a median of 9 months (range, 2-41 months); 12 (66%) of these patients initially had stage IVa disease, and 6 (33%) had stage IV b disease. Five patients had an undifferentiated type of histology. The median time to progression was 5 months. However, none of these patients was able to receive salvage therapy due to their poor performance status. For those patients with a lymphoepithelioma-like histology, the median survival was 36 months; there was tumor recurrence in five patients and they all received salvage chemotherapy. The median survival time for these five patients was 51 months. For patients with squamous cell type, the median time to progression was 10 months. Five patients received salvage chemotherapy and the median survival was 28 months. There was a significant difference (P < 0.0001) in the median survival between those who received chemotherapy (18 months) after tumor relapse and those who did not (1 month).
Conclusions: Our results indicate that multidisciplinary treatment, including surgery, radiotherapy, and chemotherapy, is beneficial in treating primary thymic carcinoma. Chemotherapy plays an important role in both primary and relapsed stage IV thymic carcinoma in terms of prolonging the disease-free survival and median survival of patients with lymphoepithelioma-like or squamous cell histology types. For patients with an undifferentiated histology, multidisciplinary treatment or chemotherapy might not be helpful in either primary or relapsed stage IV thymic carcinoma.