Evaluation of Gastroenteropancreatic Neuroendocrine Tumors

The incidence of Gastroenteropancreatic Neuroendocrine Tumors (GEP-NETs) was shown to be steadily increasing (~4-5% per year), especially in the older population, by a recent publication by Lee et al.¹ As the patients’ survival is directly related to their management, the treating oncologist is heavily dependent on the correct grading/staging by the pathologist. Currently there is a lack of clarity with the scoring of Ki67 staining and the best specimens to test.

Scope

The primary goal of this guideline is to provide evidence-based recommendations on the evaluation of GEP-NETs. The guideline scope begins with specimens submitted to the laboratory with confirmed diagnosis of GEP-NET. Specimens under review will include fine needle aspirations, biopsies, surgical resections of both primary tumors, and metastases.

Key Questions

The draft overarching questions include:

• What is the best Ki67 scoring method of assigning grades in GEP-NETs?
• What are the best specimens to grade in GEP-NETs?

Key questions would be developed around the pre-analytic factors of specimen adequacy and the analytic factors of testing, counting, and interpretation.

Guideline Information

Guideline Status: Open Comment Period

Collaborators: The North American Neuroendocrine Tumor Society (NANETS) and the European Neuroendocrine Tumor Society (ENETS)

Open Comment Period Information 
All stakeholders— pathologists, gastroenterologists, oncologists, histotechnologists, hospital or laboratory managers, and patient advocacy group representatives—are encouraged to review and submit feedback on the draft recommendations from March 17 to April 10.

Review the following resources to provide your feedback:

• Data extraction references

• Draft recommendations

• Grades for certainty of evidence and strength of recommendations

• Expert panel disclosures of interest report

Expert Panel Members

Rahul M. Jawale, MD, FCAP, Co-Chair
Chanjuan Shi, MD, PhD, FCAP, Co-Chair
Dana L. Altenburger, MD, FCAP
Adam L. Booth, MD, FCAP
Chandrikha Chandrasekharan, MBBS
Deyali Chatterjee, MD, FCAP
Robert M. Najarian, MD, FCAP
Guido Rindi, MD, PhD
Lesley Souter, PhD
Zhaohai Yang, MD, PhD, FCAP
Marisol Hernandez, MA, MLS, Staff
Christina B. Ventura, MPH, MLS(ASCP), Staff

PROSEPRO Listing

1. Lee MR, Harris C, Baeg KJ, et al. Incidence trends of gastroenteropancreatic neuroendocrine tumors in the United States [published online December 20, 2018]. Clin Gastroenterol Hepatol. 2018. doi: 10.1016/j.cgh.2018.12.017

Disclaimer

The information, data, and draft recommendations provided by the College of American Pathologists are presented for informational and public feedback purposes only.
The draft recommendations and supporting documents will be removed on April 14, 2025. 
The draft recommendations along with the public comments received and completed evidence review will be reassessed by the expert panel in order to formulate the final recommendations. These draft materials should not be stored, adapted, or redistributed in any manner.

Please note: Comments are not posted automatically. All comments will be posted on a weekly basis beginning March 24, 2025.
Following the open comment period, the guideline authors will consider all feedback to finalize the recommendations. The final recommendations will be formally published as a guideline in Archives of Pathology & Laboratory Medicine.
The CAP Pathology and Laboratory Quality Center for Evidence-based Guidelines (Center) develops recommendations related to the practice of pathology and laboratory medicine. Through this work, we and our members continually improve the quality of diagnostic medicine and patient outcomes. For questions, please contact CENTER@CAP.ORG.