For patients (and parents of patients) that have been diagnosed with, pediatric acute lymphoblastic leukemia (ALL), nausea and vomiting are among the most bothersome symptoms during chemotherapy treatment. The overall goal of this study is to find the best strategies used by parents and patients for managing these symptoms when receiving maintenance therapy.

The goal of this observational study is to describe the safety and effectiveness of larotrectinib in patients with locally advanced or metastatic TRK fusion cancer for whom a decision to treat with larotrectinib has been made before enrollment. This study will enroll participants with any tumors harboring the NTRK gene fusion including Soft Tissue Sarcomas, Central Nervous System, Melanoma, and Thyroid cancers.