Hyperthermic intraoperative chemotherapy (HIOC) for Stage IVa thymic malignancy may improve 5-year disease-free survival

Background and objectives: Stage IVa thymic malignancy has limited treatments. This study evaluated whether hyperthermic intraoperative chemotherapy (HIOC) after radical resection of Stage IVa thymic malignancy improves survival.

Methods: All patients who underwent resection, with or without HIOC, for Stage IVa thymic malignancy at a single center from 1990 to 2021 were reviewed.

Results: Thirty-four patients were identified; 22 surgery-only versus 12 surgery and HIOC (60 min cisplatin regimen 175 mg/m² ). Demographics and comorbidities were similar between groups. Three patients in each group were carcinomas; remainder were thymomas. Thirty-two patients underwent attempted macroscopic complete resection; 22 operations succeeded, 68.8%. Significant complications were similar between groups, 18.2% surgery-only versus 25.0% HIOC, p = 0.68. Median time to recurrence trended longer for HIOC patients (42.9 vs. 32.9 months in surgery-only, p = 0.77). Overall survival, 5-year, was similar (75.8% HIOC vs. 76.2% surgery-only, p = 0.91). On stratified analysis, thymoma patients with macroscopic complete resection and HIOC experienced similar 5-year Overall (80.0% vs. 100.0% surgery-only, p = 0.157) but longer trending 5-year disease-free (85.7% vs. 40.0%, p = 0.18) and 5-year locoregional recurrence-free survival (85.7% vs. 68.6%, p = 0.75).

Conclusions: This retrospective cohort study treating Stage IVa thymic malignancy with radical pleurectomy, with or without HIOC, found addition of HIOC-signaled delayed recurrence and improved disease-free survival.