Treatment of metastatic carcinoid tumors with radiolabeled biologic molecules.

Treatment options in advanced-stage neuroendocrine tumors are limited. A promising new category of therapy was recently introduced for these tumors in which radioactive atoms are attached to molecules that target and bind to neuroendocrine cancer cells. 90Yttrium-DOTA-Phe1-Tyr3-octreotide and radioactive drugs which targets cells by binding to somatostatin receptors. 131Iodine-metaiodobenzylguanidine also targets neuroendocrine tumors using the amine transporter system. Both agents, along with the somatostatin analogue 177Lutetium-DOTATATE, have shown objective response rates in approximately 30% of patients with progressive metastatic disease. Symptomatic improvement is observed in most patients receiving these drugs and evidence of survival benefit is also mounting. Serious side effects are uncommon.