Efficacy and safety of perioperative immunotherapy for locally advanced thymic squamous cell carcinoma: a retrospective pilot study.

[BACKGROUND] Thymic squamous cell carcinoma (TSCC), the predominant subtype of thymic carcinoma, is a rare and aggressive malignancy. Although the clinical benefits of perioperative immunochemotherapy for non-small cell lung cancer have been confirmed, its role in TSCC remains unclear. This study was performed to evaluate the efficacy and safety of perioperative immunotherapy for locally advanced TSCC.

[METHODS] The clinical data of 10 locally advanced TSCC patients treated with perioperative immunotherapy were retrospectively analyzed. All the patients received neoadjuvant PD-1 inhibitors plus platinum-based chemotherapy, followed by surgery and adjuvant immunotherapy. Surgical and pathological outcomes, postoperative complications, treatment-related adverse events (TRAEs), and survival outcomes were all assessed.

[RESULTS] After neoadjuvant immunotherapy, 60% (6/10) of patients achieved partial response and 40% (4/10) obtained stable disease, with the objective response rate of 60% and disease control rate of 100%. R0 resection was achieved in 80% (8/10) of patients, with 2 achieving complete pathological response. All the patients experienced at least one grade 1-2 TRAEs, but no grade 3-4 TRAEs occurred. The most commonly TRAEs were anorexia (70%) and alopecia (70%), followed by fatigue (60%). During the follow-up of 30 months, only 2 patients were dead, with recurrence-free survival of 17 and 19 months and overall survival of 23 months for both.

[CONCLUSION] Perioperative immunotherapy exhibits a promising resectable rate in locally advanced TSCC, with a manageable safety profile, although survival benefits have yet to be established. In the future, a prospective randomized controlled trial should be performed to further clarify the role of perioperative immunotherapy for locally advanced TSCC.