Radiotherapy in Thoracic NUT Carcinoma: A Pooled Analysis of Long-term Survivors and Clinical Outcome Heterogeneity.

BACKGROUND: Thoracic NUT carcinoma is a rare and highly aggressive malignancy. Real-world evidence to guide radiotherapy (RT) remains limited. We performed a pooled RT-focused analysis to characterize treatment contexts, outcomes, and the clinical features of long-term survivors (LTS). METHODS: A systematic review of six databases identified 111 patients receiving thoracic RT. The earliest thoracic-directed course was defined as the index RT. Analyses were prespecified as descriptive and stratified by metastatic status at diagnosis. Outcomes included overall survival (OS), RT-progression-free survival (RT-PFS), symptom-control duration to next intervention (SCD-NI), and RECIST-based response. LTS were defined a priori as OS ≥24 months. RESULTS: Median OS for the overall cohort was 9.7 months. Patients with bone metastasis had shorter survival than those without bone metastasis. Fifteen patients met the definition of LTS. Compared with others, LTS had similar RECIST response patterns but smaller tumors, less metastatic disease, no documented bone metastasis, and more frequent complete resection and CRT. Median RT-PFS among curative RT/CRT cases was 5.3 months. In the palliative RT subgroup, median SCD-NI was 3.0 months, indicating short-term clinical stabilization. Trajectory analyses showed heterogeneous courses among long-term survivors. CONCLUSIONS: Thoracic RT in NUT carcinoma was used across diverse clinical contexts and was associated with short-term palliation and, in selected patients, prolonged disease control. Long-term survivors were enriched for lower metastatic burden, absence of bone metastasis, and multimodality treatment, suggesting that factors beyond initial radiographic response may contribute to prolonged survival, although these findings should be interpreted descriptively given the retrospective case-based design.