Systemic Therapy for Tumor Control in Metastatic Well-differentiated Gastroenteropancreatic Neuroendocrine Tumors
Treatment
I. General Recommendations for G1–G3 GEP-NETs
Recommendation 1.1
- While local therapy options are outside the scope of this systematic review and guideline, surgical cytoreduction (if feasible to achieve >70–90% reduction in tumor volume) or other types of liver-directed therapy (e.g., embolization) may be considered for patients with hepatic disease, and preferably should be discussed within the setting of an MDT.
- In addition, while the use of somatostatin analogs (SSAs) for symptom management is outside the scope of these guidelines, SSAs are often used indefinitely in patients with functional NETs.
Recommendation 1.2
Recommendation 1.3
II. Systemic Therapy for Metastatic G1–G2 Gastrointestinal NETs (GI-NETs)
First-line Systemic Therapy for G1–G2 GI-NETs
Recommendation 2.1
- Observation and surveillance with anatomic imaging (computed tomography [CT] or magnetic resonance imaging [MRI]) every 3–6 months, with extension to 6–12 months for patients with consistently stable disease, can be considered for patients with low volume metastatic G1–G2 GI-NETs, and an absence of symptoms from tumor burden or a functional tumor. For patients with bone-dominant metastases, follow-up with SSTR-PET imaging is recommended, due to the limited sensitivity of anatomic imaging for these metastases.
- Evidence supporting SSA use for tumor control is strongest in patients with low or low-intermediate grade SSTR-positive tumors (Ki-67 <10%).
Recommendation 2.2
Second- or Later-line Systemic Therapy for G1–G2 GI-NETs
Recommendation 2.3
- In addition to PRRT, continuation of treatment with SSAs is recommended for functional tumors; there is insufficient efficacy data to suggest that SSAs should be continued in patients with non-functional tumors at disease progression.
- Patients with low volume of metastases should weigh the potential benefits of PRRT with the potential risk of long-term bone marrow toxicities.
Recommendation 2.4
- Although the evidence base for everolimus is in patients with non-functional tumors, this agent may also be considered as later-line therapy for functional tumors.
III. Systemic Therapy for Metastatic G1–G2 Pancreatic NETS (panNETs)
First-line Systemic Therapy for G1–G2 panNETs
Recommendation 3.1
- Observation and regular anatomic imaging (CT or MRI) every 3–6 months, with extension to 6–12 months for patients with consistently stable disease, can be considered for patients with low volume metastatic G1–G2 panNETs, and an absence of symptoms from tumor burden or a functional tumor. For patients with bone-dominant metastases, follow-up with SSTR-PET imaging is recommended, due to the limited sensitivity of anatomic imaging for these metastases.
- Evidence supporting SSA use for tumor control is strongest in patients with low or low-intermediate grade SSTR-positive tumors (Ki-67 <10%).
Recommendation 3.2
- In the rare circumstance of patients with higher volume panNETs and/or symptoms related to tumor burden who are not candidates for chemotherapy, PRRT for patients with SSTR-positive tumors, or sunitinib or everolimus are recommended.
Recommendation 3.3
Second- or Later-line Systemic Therapy for G1–G2 panNETs
Recommendation 3.4
- At this time, there is insufficient evidence to recommend a particular sequence of systemic therapy options following progression on SSAs for patients with G1–G2 panNETs; the order of options in Recommendation 3.4 is not intended to suggest a particular sequencing strategy.
Qualifying statements:
- In addition to PRRT, continuation of treatment with SSAs is recommended for functional tumors; there is insufficient efficacy data to suggest that SSAs should be continued in patients with non-functional tumors at disease progression.
- RCTs have not been published to date with PRRT in panNETs.
- Patients with low volume of metastases should weigh the potential benefits of PRRT with the potential risk of long-term bone marrow toxicities.
- Everolimus and sunitinib are cytostatic agents, and are associated with tumor stability, while chemotherapy and PRRT are associated with tumor response.
- Comorbidities may be considered during selection of therapy; sunitinib is not recommended for patients with uncontrolled hypertension, and everolimus is not recommended for patients with uncontrolled diabetes.
IV. Systemic Therapy for G3 GEP-NETs
Recommendation 4.1
- G3 GEP-NETs are a relatively newly defined category within neuroendocrine neoplasms, and include a wide Ki-67 proliferation index range (i.e., >20%). Several trials, as outlined in the full-text guidelinea are currently underway to inform specific therapy options, and may be used to inform recommendations for subpopulations of G3-NETs patients in the future.
Qualifying statements:
- SSAs alone may be considered as first-line treatment in select cases (i.e., SSTR-positive, low volume of disease, low tumor-related symptom burden, less rapid rate of growth).
- PRRT with or without SSAs is a potential treatment option for patients with SSTR-positive G3 GEP-NETs with characteristics such as less rapid rate of growth, and lower volume of disease who have progressed on SSAs alone.
- Chemotherapy may be particularly effective for patients with characteristics such as higher proliferation index and/or mitotic rate, rapid rate of growth, and bulky disease. Evidence for cytotoxic chemotherapy is strongest for panNETs.
Recommendation Grading
Disclaimer
Overview
Title
Systemic Therapy for Tumor Control in Metastatic Well-differentiated Gastroenteropancreatic Neuroendocrine Tumors
Authoring Organization
American Society of Clinical Oncology
Publication Month/Year
September 27, 2023
Last Updated Month/Year
September 30, 2024
Supplemental Implementation Tools
Document Type
Guideline
Country of Publication
US
Document Objectives
To develop recommendations for systemic therapy for well-differentiated grade 1 (G1) to grade 3 (G3) metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs).
Target Patient Population
Patients with well-differentiated metastatic G1-G3 GEP-NETs.
Target Provider Population
Medical oncologists, including community oncologists, nuclear medicine physicians, and other healthcare professionals who are involved in the care and treatment of patients with metastatic G1-G3 GEP-NETs.
PICO Questions
What is the recommended initial and subsequent-line systemic treatment for G1-G2 GI-NETs?
What is the recommended initial and subsequent-line systemic treatment for G1-G2 pancreatic NETs (panNETs)?
What is the recommended systemic therapy for G3 GEP-NETs?
Inclusion Criteria
Male, Female, Adult, Older adult
Health Care Settings
Ambulatory, Outpatient
Intended Users
Nurse, nurse practitioner, physician, physician assistant
Scope
Counseling, Assessment and screening, Treatment
Diseases/Conditions (MeSH)
D009362 - Neoplasm Metastasis, D006528 - Carcinoma, Hepatocellular, D018278 - Carcinoma, Neuroendocrine, D018358 - Neuroendocrine Tumors, D008113 - Liver Neoplasms, D018323 - Hemangioendothelioma, Epithelioid, D018197 - Hepatoblastoma
Keywords
Neuroendocrine tumor, Neuroendocrine neoplasm, pancreatic neuroendocrine tumor, gastrointestinal neuroendocrine tumor, GEP-NETs
Source Citation
Del Rivero J, Perez K, Kennedy EB, et al. Systemic Therapy for Tumor Control in Metastatic Well-differentiated Gastroenteropancreatic Neuroendocrine Tumors: ASCO Guideline. J Clin Oncol. 2023 Sept 29. doi:10.1200/JCO.23.01529