Clinical and Prognostic Characteristics of 40 Cases of INI1-deficient Tumor in Children. A Single-Institute Experience from 2012 to 2022

Background This study aims to summarize the clinical features and prognoses of INI1-deficient tumors in children. It further aims to analyze the high-risk factors affecting INI1-deficient tumors prognosis. Methods Clinical data from 40 children with INI1-deficient tumors treated in Beijing Children’s Hospital from January 2012 to December 2022, along with the high-risk factors affecting prognosis, were retrospectively analyzed. Results Forty patients were diagnosed with INI1-deficient tumor at a median age of 32.5 months, including 31cases of malignant rhabdoid tumor, 4 cases of epithelioid sarcoma, 3 cases of malignant peripheral nerve sheath tumor, 1case of soft tissue myoepithelial carcinoma and 1 case of small cell carcinoma of the ovary with hypercalcemia. Thirteen patients(13/40, 32.5%) had metastases at diagnosis. Among the 40 patients, 21 patients died, including 6 patients with MRTK, 9 patients with EERT, 5 patients with AT/RT and 1 patients with SCCOHT. The overall survival rates of 1 years and 3 years for the entire cohort were 53.8%±8.0% and 43.6%±8.6% respectively. After survival analysis, it was clear that malignant rhabdoid tumor, lung metastasis and ki 67>60% had relatively poor outcomes. Lung metastasis was an independent risk factor for the prognosis of INI1-deficient tumor. Conclusion INI1-deficient tumor is a highly aggressive tumor in children especially with lung metastasis. Much work should do to improve the outcomes and survival for patients with aggressive INI1-deficient tumors.