Larotrectinib in Adjuvant and First‐Line Treatment for Metastatic NTRK Fusion Colon Cancer

We report an 83-year-old woman with severe concomitant pathology who underwent surgery for colon cancer, with recurrent bleeding from the tumor, and subcompensated intestinal stenosis. After right-sided hemicolectomy with regional lymph node dissection, the disease was staged as pIIIC, and a translocation of the NTRK1 (Neurotrophic Tyrosine Receptor Kinase) gene was detected. The patient required adjuvant treatment, given the high risk of disease progression, but due to her severe concomitant pathology, chemotherapy was contraindicated. Adjuvant therapy with larotrectinib was recommended given NTRK gene translocation. According to examination data after three months, there was no progression. Following this, the patient decided to stop larotrectinib. Subsequently, disease progression was detected in the form of abdominal carcinomatosis, after which larotrectinib was resumed. At the time of this clinical case report, therapy is ongoing for 21 months without any signs of further disease progression. This study demonstrates the efficacy and safety of larotractinib as both adjuvant therapy and first-line therapy in a complex clinical case of colon cancer against the background of severe concomitant pathology, when chemotherapy is contraindicated.