What is the recommended follow-up for patients with Intraductal Papillary Mucinous Neoplasm (IPMN)?

Follow-Up Protocol for Intraductal Papillary Mucinous Neoplasm (IPMN)

Lifelong surveillance is recommended following diagnosis of an IPMN as long as the patient is fit and willing to undergo surgery if indicated, with the specific follow-up protocol determined by IPMN type and pathology. 1

Follow-Up Based on IPMN Type and Pathology

For Non-Resected IPMN

The surveillance protocol should be stratified by cyst size:

• Cysts <20mm without worrisome features:

  • Initial 6-month follow-up
  • Then every 18 months if stable 2

• Cysts 20-30mm without worrisome features:

  • Initial 6-month follow-up
  • Then yearly surveillance 2

• Cysts ≥30mm or with worrisome features:

  • Initial 6-month follow-up
  • Then every 6 months 2

For Post-Surgical IPMN

• IPMN with invasive carcinoma:

  • Follow-up identical to resected pancreatic cancer protocol 1

• IPMN with high-grade dysplasia or Main Duct IPMN:

  • Every 6 months for first 2 years
  • Then yearly surveillance 1

• IPMN with low-grade dysplasia:

  • Follow-up identical to non-resected IPMN protocol 1

• IPMN in remnant pancreas without high-grade dysplasia or MD-IPMN:

  • Follow-up identical to non-resected Branch Duct IPMN protocol 1

Imaging Modality

• MRI or EUS is the recommended imaging modality for surveillance 1
• CT may be used when MRI is contraindicated

Risk Factors for Progression

Several factors are associated with higher risk of IPMN progression:

• Symptomatic disease (HR=1.58) 3
• Current smoking status (HR=1.58) 3
• Increasing cyst size (HR=1.26 per cm) 3
• Main duct dilation (HR=3.17) 3
• Solid components/mural nodules (HR=1.89) 3
• Family history of pancreatic cancer 4

Duration of Surveillance

• Patients should undergo lifelong surveillance as long as they remain surgical candidates 1

• The risk of developing a new IPMN after resection increases over time:

  • 4% at 1 year
  • 25% at 5 years
  • 62% at 10 years 4

• The risk of developing invasive pancreatic cancer after resection:

  • 0% at 1 year
  • 7% at 5 years
  • 38% at 10 years 4

Special Considerations

• Margin status: Positive margins for IPMN at initial operation do not significantly increase the risk of developing a new IPMN (20% vs 16% for negative margins) 4

• Family history: Patients with a family history of pancreatic cancer have a higher risk of developing new or progressive IPMN (23% vs 7%) 4

• Organ transplant recipients: Surveillance should be the same as for non-transplanted patients 1

Potential Discontinuation of Surveillance

Surveillance may potentially be discontinued in patients with:

• Cysts <20mm with no worrisome features and no growth during 5 years of surveillance
• Limited life expectancy (<10 years)
• Patients unfit for surgery 2

Pitfalls to Avoid

1. Don't rely solely on cyst size: While size is important, mural nodules, MPD dilation ≥5mm, and elevated CA19-9 are stronger predictors of malignancy 5

2. Don't neglect remnant pancreas: After partial pancreatectomy, the remaining pancreas still requires surveillance as new IPMNs can develop 4

3. Don't assume volumetric measurements are superior: Despite the irregular shape of many IPMNs, volumetric measurements have not been proven to predict malignancy better than traditional diameter measurements 5

4. Don't underestimate progression risk: Most progression occurs within the first year after presentation, requiring vigilant early follow-up 3