Differentiating TRK Proteins in Adults and Adolescents With Solid Tumors

Alexander Drilon, MD, discusses the differences in how TRK fusions manifest in older patients vs younger patients.

Alexander Drilon, MD, a medical oncologist, and chief of the Early Drug Development Service at Memorial Sloan Kettering Cancer Center, discusses the differences in how TRK fusions manifest in older patients vs younger patients.

According to Drilon, research has revealed that the presence of NTRK gene fusions in solid tumors and the activity of the TRK inhibitors that are currently available have allowed for new innovations in regard to precision medicine in this setting.

NTRK gene fusions can be found in a wide variety of patients, including infants, children, and adults. Because of this, multiple studies have examined larotrectinib in both adult and pediatric patients, including patients with central nervous system involvement. Findings have revealed that larotrectinib shows promise and elicits robust and durable responses in this patient population.


0:08 | The TRK family of proteins is intimately involved in both the development and maintenance of the nervous system. From a practical perspective, in adults, that means that it controls things like appetite, the functioning of nerves that are involved in maintaining balance, and other nerves. When they are irritated or hyper activated, that might result in paresthesia.

0:39 | NTRK fusions are found across many different cancers both in adults and in pediatric patients, and that includes infants, children, adolescents, and young adults. The different cancers that are found in adults vs the pediatric population include a higher frequency of some rare tumors in kids or infants like congenital fibrosarcoma, for example. While there are other, more common cancers where the frequency of an entrapped fusion is lower, such as lung cancer, gastrointestinal tumors, or non-secretory breast cancers, where those cancers cluster largely in the adult population. There is a difference in the profile of the tumor types that we see in infants and kids, adolescents, vs adults.