Casting a Wide NET: When Is the Optimal Time for 177Lu-Dotatate Treatment?

The incidence of neuroendocrine tumors (NETs) in the US is rising, with 8.3 cases per 100,000 individuals diagnosed in 2018 compared with 6.98 cases per 100,000 individuals diagnosed in 2012. 1,2 Most patients with NETs are diagnosed with metastatic disease, at which point curative surgery is no longer a treatment option. 3 Prior to 2017, available treatments for advanced NETs included somatostatin analogues (lanreotide [Somatuline] and octreotide [Sandostatin]), targeted therapy (everolimus [Afinitor] and sunitinib [Sutent]), and chemotherapy. 4-7 In 2017, the World Health Organization added a classification for well-differentiated grade 3 NETs (Ki67 > 20% and ≤ 55%). 8 Previously these tumors were placed under the umbrella of poorly differentiated neuroendocrine carcinomas. Given that well-differentiated grade 3 NETs are relatively new, standard-of-care treatment options are undefined.