A rare case of invasive thymoma presented a dramatic response to low-dose prednisolone as a single-drug therapy

The remarkable antitumor efficacy of corticosteroid treatment in patients with refractory thymomas

BACKGROUND

Some case reports have found that corticosteroid treatments shrunk thymoma lesions remarkably after the failure of chemotherapy or surgery. However, few studies have comprehensibly evaluated the antitumor effects of corticosteroids in patients with invasive thymomas.

METHODS

We reviewed the medical records of 13 consecutively enrolled patients with locally advanced or metastatic thymomas treated via corticosteroid monotherapies from January 2010 to March 2021 in our institute. A Cox's proportional hazard model and the Kaplan-Meier method were used to identify factors associated with survival.

RESULTS

The median follow-up time was 26 months (range, 13-115 months). The median initial dose of corticosteroid was 0.90 mg/kg/day prednisolone equivalent (range, 0.4-1.1 mg/kg/day). Of the 13 cases, 7 (53.8%, 95% CI: 0.25-0.81) exhibited a partial response and 5 (38.5%, 95% CI: 0.14-0.68) stable disease. The median progression-free survival was 5.7 months [95% confidence interval (CI): 1.5-9.6 months]. The median overall survival was 25.3 months (95% CI: 7.1-not attained). The median duration of corticosteroid use was 3 months (range, 1-64 months). Patients with WHO subtype B thymomas exhibited a better overall response rate to corticosteroids than did patients with other disease subtypes (75%, 95% CI: 0.19-0.99). Adverse events of Grade 3 or more were not observed.

CONCLUSIONS

Corticosteroids are clinically valuable for patients with thymomas.

Successful treatment of type B2 thymoma with steroid and radiotherapy

An 86-year-old woman with leg edema and dyspnea on exertion was admitted to our hospital. Chest computed tomography (CT) revealed a mass in the anterior mediastinum with pericardial invasion. Histological examination with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) led to the diagnosis of Masaoka stage IVa type B2 thymoma. For palliation, radiotherapy (32 Gy/16 fractions) and prednisolone (30 mg/day) were administered and tapered. After treatment, both the pericardial effusion and tumour size decreased. Combination therapy with steroids and radiotherapy may be effective for treating thymomas.