Should a patient with smoldering myeloma and a positive Fecal Immunochemical Test (FIT) undergo a colonoscopy or be referred to oncology first?

Order Colonoscopy Immediately—Do Not Defer to Oncology

A positive FIT test mandates colonoscopy regardless of the patient's smoldering myeloma diagnosis, and this should be arranged directly without deferring to oncology. 1 The presence of smoldering myeloma does not change the standard approach to a positive FIT result, which requires prompt colonoscopic evaluation.

Why Colonoscopy is Mandatory

• When FIT is positive, colonoscopy is the recommended test for subsequent evaluation with strong recommendation and moderate-quality evidence. 1
• A positive FIT has a 40-47% positive predictive value for advanced neoplasia, making colonoscopy non-negotiable. 2
• Delays in colonoscopy beyond 6 months after positive FIT significantly increase risks: adjusted OR 1.31 for any colorectal cancer and 2.09 for advanced-stage disease. 1, 3
• Delays beyond 10-12 months show even worse outcomes, with OR 1.48-2.25 for any colorectal cancer and OR 1.97-3.22 for advanced-stage disease. 4, 5

Timing Requirements

• Schedule colonoscopy within 3 months of the positive FIT result, with an absolute maximum delay of 6 months. 1, 2
• Optimally, colonoscopy should be performed within 30 days when feasible. 1, 2
• There is no significant difference in outcomes for colonoscopy performed at 1-3 months versus 3-6 months, but risks increase substantially after 6 months. 3, 4

Why Oncology Referral is Not Necessary First

• Smoldering myeloma is an asymptomatic precursor condition that does not typically cause gastrointestinal bleeding or interfere with colonoscopy. [@General Medicine Knowledge@]
• The positive FIT indicates a gastrointestinal source of bleeding that requires direct evaluation, independent of the hematologic diagnosis. 1
• Deferring to oncology will only delay necessary diagnostic evaluation and potentially miss significant colorectal lesions. 6

Coordination with Oncology

• Inform the patient's oncologist about the planned colonoscopy for coordination purposes, particularly regarding: [@General Medicine Knowledge@]
  • Platelet count assessment (ensure >50,000/μL for safe polypectomy)
  • Coagulation parameters if the patient is on any anticoagulation
  • Timing relative to any planned myeloma treatments
• However, do not wait for oncology clearance to schedule the colonoscopy—proceed with scheduling while coordinating these details. [@General Medicine Knowledge@]

Quality Requirements for the Colonoscopy

• The colonoscopy must be complete to the cecum and of high quality. 1, 2
• Ensure adequate bowel preparation, as poor preparation may necessitate repeat examination. [@General Medicine Knowledge@]
• The adenoma detection rate should exceed 45% in men and 35% in women for colonoscopies evaluating FIT positivity. 1

Common Pitfalls to Avoid

• Do not repeat FIT instead of proceeding to colonoscopy—colonoscopy is mandatory when FIT is positive. 1, 2
• Do not delay colonoscopy to obtain "oncology clearance" unless there are specific contraindications like severe thrombocytopenia (<20,000/μL) or active bleeding diathesis. [@General Medicine Knowledge@]
• Do not assume the positive FIT is related to the myeloma without colonoscopic evaluation, as this represents a diagnostic error. 6

If Colonoscopy is Negative

• In the absence of signs or symptoms of upper gastrointestinal pathology, a positive FIT with negative colonoscopy should not prompt upper gastrointestinal evaluation. 1
• Consider repeat colonoscopy if the initial examination was incomplete or of poor quality. [@General Medicine Knowledge@]