Accelerated Death in Patients with MPNST Associated with NF-1 Who have Started Radiotherapy Compared with non-NF1

Background: MPNST are large deep soft tissue sarcomas affecting those with and without NF-1. Usual treatment paradigm includes surgery with a goal of R0 resection, preceded by radiation. Chemotherapy plays a limited role in this disease. The concern is always the development of distant metastatic disease, especially in the lung, as this renders the patient incurable, and usually guarantees death within 2 years. As the tumours are often deep, affecting major limbs and/or joints, and therefore surgery is accompanied by significant rehabilitation needs. Moreover, the tumours themselves are associated with significant pain, requiring substantial amounts of pharmacological support. Overall, the patients with MPNST endure significant suffering throughout their journey. Our clinical experience suggests that patients with NF1 unfortunately develop lung metastases with a very short time frame following the start of radiotherapy, leading to death within 1 year from initial diagnosis. We aim to embark on a retrospective review of our patients to determine if the disease trajectory is hastened with the start of RT in NF1 patients compared with non-NF1 patients. We will answer this question by comparing the event-free and overall survival between NF1 and non-NF1 patients who initially present with localized MPNST. Methods: Using CanSaRCC database, review demographics, treatment and outcome data. Analysis: We will use chi square test to compare demographic features and logistic regression to compare Kaplan-Meier estimates of EFS and OS between the 2 groups.