Introduction: Pleural metastases are common among patients with thymic carcinoma. Accurate and consistent measurement of pleural lesions is often difficult because of their unique locations and growth patterns. To minimize intraobserver variability, the International Thymic Malignancies Interest Group (ITMIG) proposed modified criteria for measurement of tumor response for thymic epithelial tumors.
Methods: We conducted a retrospective review of the medical records of advanced or recurrent thymic carcinoma patients treated with chemotherapy between 1980 and 2016 in our institution. The best objective responses were assessed using the Response Evaluation Criteria in Solid Tumor version 1.1 (RECIST 1.1) and the ITMIG-modified criteria.
Results: A total of 26 patients were included in the present study. According to the RECIST criteria, 1 (3.8%) patient showed complete response (CR), and 13 (50.0%), 10 (38.5%), and 2 (7.7%) showed partial response (PR), stable disease (SD), and progressive disease (PD), respectively. All 26 patients had the same best overall response using the ITMIG criteria. The median time to progression (TTP) according to the RECIST criteria and the ITMIG-modified criteria was 5.5 months (95% confidence interval [CI] 3.8-8.6) and 7.0 months (95% CI 3.8-9.3), respectively (p = 0.993).
Conclusion: The ITMIG-modified criteria showed a high concordance rate with RECIST 1.1 criteria in response assessment of thymic carcinoma.
Keywords: Pleural disease; Rare cancer; Response evaluation criteria in solid tumors; Thymic carcinoma.
© 2019 S. Karger AG, Basel.