Are all neuroendocrine tumors treated with lanreotide?

Lanreotide Use in Neuroendocrine Tumors

No, not all neuroendocrine tumors receive lanreotide—it is specifically indicated for unresectable, well to moderately differentiated, locally advanced or metastatic gastroenteropancreatic NETs, and should only be used in somatostatin receptor-positive tumors. 1, 2

Specific Indications for Lanreotide

Tumor Control (Antiproliferative Effect)

• Lanreotide is recommended for patients with clinically significant tumor burden or progressive disease to control tumor growth in gastroenteropancreatic NETs with Ki-67 proliferative index up to 10% 1, 2
• The CLARINET study demonstrated significant improvement in progression-free survival (PFS not reached vs 18 months with placebo; HR 0.47, P<0.001), with estimated PFS of 32.8 months in the open-label extension 1, 3
• Treatment benefit applies specifically to nonfunctioning pancreatic or intestinal NETs that are well to moderately differentiated 1

Symptom Control

• Lanreotide is effective for managing carcinoid syndrome symptoms including flushing and diarrhea, with 34% rescue octreotide use compared to 49% with placebo (P=0.02) 1, 2
• Also indicated for symptom control in gastrinomas and VIPomas 1, 2

Critical Exclusion Criteria

Somatostatin Receptor Status

• Treatment will likely only benefit somatostatin receptor-positive patients confirmed by octreotide scintigraphy (Octreoscan) 1
• In one study, 23 of 25 patients (92%) were octreotide scintigraphy positive before treatment 4

Tumor Grade and Differentiation

• Lanreotide is not indicated for poorly differentiated or high-grade (Ki-67 >10%) NETs 1, 3
• The CLARINET study specifically enrolled patients with grade 1 or 2 tumors only 3

Clinical Decision Algorithm

For Symptomatic Patients (Carcinoid Syndrome)

• Initiate lanreotide 120 mg subcutaneously every 4 weeks for both symptom control and tumor growth control 2, 5
• Consider cardiology consultation and echocardiogram if 5-HIAA levels ≥300 mcmol/24 hours and ≥3 flushing episodes per day (59% risk of carcinoid heart disease) 1

For Asymptomatic Patients with Low Tumor Burden

• No clear consensus exists on timing of initiation in asymptomatic patients with metastatic NETs and low tumor burden 1
• Options include: observation with imaging every 3-12 months, or initiation of lanreotide for tumor control 2
• Deferring initiation until evidence of tumor progression may be appropriate in selected patients 1

For Progressive Disease

• Initiate lanreotide immediately if not already receiving it in patients with clinically significant tumor burden or documented progression 1
• Most patients in CLARINET (96%) had stable disease in the 3-6 months before randomization, yet still benefited 3

Important Clinical Caveats

Interchangeability with Octreotide

• Lanreotide shares the same mechanism of action as octreotide, making both appropriate options for tumor control 2
• Real-world data shows patients transitioning from octreotide to lanreotide maintained disease control, with median PFS of 23.7 months after transition 6
• Even patients with progressive disease on octreotide achieved median PFS of 15.2 months after switching to lanreotide 6

Safety Monitoring

• Gallbladder abnormalities occur in approximately 26% of patients 2
• May cause transient glucose intolerance through reduction of postprandial insulin secretion 2
• Can cause fat malabsorption and vitamin A and D malabsorption 2
• Most common adverse event is diarrhea (26% vs 9% with placebo) 3

Contraindications in Specific NET Types

• Use extreme caution or avoid in insulinomas—lanreotide can suppress counterregulatory hormones and precipitously worsen hypoglycemia with potentially fatal complications 7

Dosing Adjustments

• Standard dose is 120 mg every 4 weeks for gastroenteropancreatic NETs 2, 5
• No dose adjustment needed for mild to moderate renal impairment 5
• Patients with severe renal or hepatic impairment were not adequately studied 5