What's the next step for a gastric NET patient with elevated gastrin and recent EGD findings, on rosuvastatin for dyslipidemia?

Management of Post-Resection Gastric NET with Persistent Hypergastrinemia

This patient requires immediate evaluation to determine the cause of persistent hypergastrinemia, starting with gastric pH measurement and temporary PPI discontinuation if on one, followed by ongoing endoscopic surveillance every 6-12 months for the first 3 years, then annually thereafter. 1

Immediate Diagnostic Steps

Determine NET Type and Hypergastrinemia Etiology

• Measure gastric pH during next endoscopy - this is the key discriminator between NET types 1

  • pH >4-5 indicates Type 1 gastric NET (achlorhydria from atrophic gastritis)
  • pH <2 indicates Type 2 gastric NET (gastrinoma/Zollinger-Ellison syndrome)

• Stop any proton pump inhibitors for 1-2 weeks and remeasure fasting gastrin to confirm elevation is not spurious 1, 2

  • PPIs can cause false elevations in gastrin levels
  • This step is critical before pursuing further workup

• Check for autoimmune gastritis markers if Type 1 NET suspected 3, 4

  • Antiparietal cell antibodies (positive in 97% of pernicious anemia cases)
  • Anti-intrinsic factor antibodies (positive in 52%)

Cross-Sectional Imaging if Type 2 NET Suspected

• Obtain multiphasic CT or MRI of abdomen/pelvis if gastric pH <2 to look for duodenal or pancreatic gastrinoma 1
• Consider endoscopic ultrasound (EUS) for small duodenal gastrinomas 1

Surveillance Strategy

Endoscopic Surveillance Schedule

Follow-up endoscopy every 6-12 months for the first 3 years, then annually thereafter 5, 1

This differs from general gastric neoplasia surveillance because:

• Type 1 gastric NETs have ongoing risk of new lesion development due to persistent hypergastrinemia 5
• The patient already had multifocal disease (fundus and body polyps), increasing recurrence risk
• Surveillance should continue indefinitely given elevated risk of metachronous neoplasia 5

What to Monitor During Surveillance

• New polyp formation or increasing tumor burden 5, 1
• Size and characteristics of any residual lesions
• Biopsies of new lesions for grading and typing 5

Common pitfall: Gastrin levels remain persistently elevated in Type 1 gastric NETs due to atrophic gastritis, so serial gastrin measurements are generally uninformative for surveillance 5. Focus on endoscopic findings instead.

Management Based on Findings

If Type 1 NET (Most Likely - 70-80% of gastric NETs)

• Continue surveillance as outlined above 5, 1
• These are typically indolent with low metastatic potential 5
• Consider antrectomy only if new lesions or increasing tumor burden develops 5, 1
  • Antrectomy removes the source of gastrin production
  • Reserved for progressive disease despite endoscopic management

If Type 2 NET (Less Common)

• Locate and resect the gastrinoma (usually duodenal or pancreatic) 1
• This addresses the underlying cause of hypergastrinemia
• Requires multidisciplinary discussion with surgical oncology 5

Additional Considerations

Retained Food/Gastroparesis Issue

The endoscopy report noted retained food obscuring full inspection. Address this before next surveillance endoscopy:

• Consider gastric emptying study
• Optimize preparation with clear liquid diet and extended fasting
• May need prokinetic agents (though use caution as these can affect gastrin levels)

Rosuvastatin Continuation

Continue rosuvastatin for dyslipidemia management - there are no significant interactions with gastric NET surveillance or management 6. The statin does not affect gastrin levels or NET behavior.

PET-Dotatate Scan Consideration

PET-Dotatate scan is NOT routinely recommended for surveillance after definitive resection 5, but may be indicated if:

• Concern for metastatic disease develops
• Tumor grade is upgraded on pathology review
• Cross-sectional imaging shows suspicious lesions

Critical Next Steps Summary

1. Await current biopsy pathology results to confirm NET grade and margins
2. Measure gastric pH at next endoscopy (within 12 weeks as indicated)
3. Stop PPIs if patient is on them and recheck fasting gastrin
4. Establish surveillance endoscopy schedule: every 6-12 months × 3 years, then annually 5, 1
5. Consider antrectomy only if progressive disease 5, 1

The patient's well-differentiated G1 NETs with clear margins from prior surgery suggest Type 1 disease with favorable prognosis, but ongoing surveillance is mandatory given the multifocal nature and persistent hypergastrinemia 5.