Dr. Coston on the Investigation of Bone Metastases in Neuroendocrine Neoplasms

Tucker Coston, MD, third-year fellow, Mayo Clinic, discusses the investigation of bone metastases in patients with well-differentiated neuroendocrine neoplasms using gallium-68 (Ga68) DOTATATE positron emission tomography (PET) scans.

Historical data on the incidence of bone metastases in patients with neuroendocrine neoplasms, which were gathered using older generations of imaging, showed that these metastases occurred in approximately 6% to 12% of all patients with neuroendocrine neoplasms. Investigators sought to evaluate the incidence of bone metastases in this patient population using Ga68 DOTATATE PET scans, Coston explain.

In data presented at the 2023 Gastrointestinal Cancers Symposium, investigators extracted 1948 PET scans for 1473 patients, and 424 patients were identified for inclusion. In scans performed between May 2018 and Mary 2021, the incidence of bone metastases in evaluated patients with neuroendocrine neoplasms was 28.8%. Additionally, 64% of patients with osseous metastatic disease were asymptomatic, and 13.4% of patients with osseous metastatic disease experienced fracture.

Coston notes that fracture risk is dependent on several different factors, including grade of the tumor and type of primary tumors. Among patients with osseous metastatic disease, the fracture rate for patients with grade 1 and typical disease was 8%; those with grade 2 disease had a fracture rate of 9%, and those with grade 3 and atypical disease had a rate of 20%. Those with a grade type not specified had a fracture rate of 11%.

Additionally, the fracture rates among patients with paraganglioma/pheochromocytoma was 29%, compared with 23% for those with pancreatic neuroendocrine tumors, 20% for those with lung carcinoid, 8% for those with an unknown primary tumor type, and 7% for those with a bowel neuroendocrine tumor.

Based on the findings of the study, Coston and colleagues conclude that the data argue against the reflexive use of bone-strengthening agents in carefully selected patients with neuroendocrine neoplasms who have osseous metastatic disease, and further validation in a prospective trial could be beneficial to confirm these observations.