Purpose: To determine the objective response rate, duration of remission and toxicity of octreotide alone or with the later addition of prednisone in patients with unresectable, advanced thymic malignancies in whom the pretreatment octreotide scan was positive.
Patients and methods: Forty-two patients with advanced thymoma or thymic carcinoma were entered onto the trial, of whom 38 were fully assessable (one patient had inconclusive histology; three patients had negative octreotide scan). Patients received octreotide 0.5 mg subcutaneously tid. At 2 months, patients were evaluated. Responding patients continued to receive octreotide alone; patients with progressive disease were removed from the study. All others received prednisone 0.6 mg/kg orally qid for a maximum of 1 year.
Results: Two complete (5.3%) and 10 partial responses (25%) were observed (four partial responses with octreotide alone; the remainder with octreotide plus prednisone). None of the six patients without pure thymoma responded. The 1- and 2-year survival rates were 86.6% and 75.7%, respectively. Patients with an Eastern Cooperative Oncology Group performance status of 0 lived significantly longer than did those with a performance status of 1 (P =.031).
Conclusion: Octreotide alone has modest activity in patients with octreotide scan-positive thymoma. Prednisone improves the overall response rate but is associated with increased toxicity. Additional studies with the agent are warranted.