Run the List Podcast: Colon Cancer Screening

Hosts: Navin Kumar (with panel), featuring Dr. Sith Saker
Date: February 9, 2026

Episode Overview

This episode of Run the List delves into the ins and outs of colon cancer screening—a highly relevant topic in both primary care and gastroenterology. Host Navin Kumar is joined by Dr. Sith Saker, a gastroenterologist at Brigham and Women's Hospital, to explore risk stratification, best practices, available screening modalities, technical considerations, and practical pearls for medical trainees and practitioners. The discussion is structured around a common clinical scenario and emphasizes guideline-based, patient-centered care.

Key Discussion Points & Insights

1. Assessing Family History & Risk Stratification

• First Degree Relatives Are Key:
  Dr. Saker emphasizes that risk assessment for colon cancer hinges on “first degree relatives” (parents, siblings, children).

  “So any first degree relative with colon cancer at any age, then you would begin colonoscopy screening at age 40 or 10 years before the earliest colon cancer diagnosis.” — Dr. Sith Saker [02:00]

• Advanced Polyps = Colon Cancer Risk:
  Advanced adenomas (size >1cm, tubulovillous/villous histology, high-grade dysplasia, or advanced sessile serrated lesions) in a first degree relative should be treated the same as colon cancer in terms of screening recommendations.
• Details Matter:
  It’s important to obtain procedural and pathology reports from family members, as nuances such as polyp size and histology change the risk calculation.

Memorable Moment:
Navin highlights the two precancerous polyp types—adenomatous and serrated—and that both necessitate the same increased vigilance [03:02].

Clinical Scenario Application

• If the relative had only a small adenoma (<1cm), with no other high-risk features, the patient reverts to average risk (screening at age 45).
• Earlier screening is warranted if advanced polyps or cancer were diagnosed at a young age in the family (screening starts at age 40 or 10 years before the relative’s diagnosis).

2. Screening Modalities: Prevention vs. Detection

• Two Main Approaches:
  • Colonoscopy: Preferred for its diagnostic and therapeutic potential; visualizes the full colon and can immediately remove precancerous lesions. Typical interval: every 10 years if normal [04:31].
  • Stool-Based Testing:
    • FIT (Fecal Immunochemical Test): Annual or biennial. Non-invasive, completed at home.
    • Multitarget Stool DNA (Cologuard): Completed at home, detects blood or abnormal DNA, but cannot prevent cancer by removing polyps.

“Both are guideline-endorsed. Neither is better than the other and the effectiveness of either strategy depends heavily on patient adherence.” — Dr. Sith Saker [04:31]

• Caveat: Any positive stool-based test requires prompt follow-up colonoscopy.

Other Modalities

• CT Colonography:
  • Used mainly when colonoscopy can’t be completed (anatomic, technical, or patient factors).
  • Non-invasive, requires bowel prep, can’t biopsy or remove lesions; misses some flat/small lesions.

  “Its highest value is as a completion study after an incomplete colonoscopy.” — Dr. Sith Saker [06:32]

3. Bowel Preparation: Critical for Quality

• Practical Insight:
  A split-dose Miralax-based bowel prep is described as the institutional standard (half dose the evening before, half five-to-six hours pre-procedure), optimizing visualization.

  “It’s paramount of importance. It really helps in making sure that there’s no small polyps or lesions missed...” – Dr. Sith Saker [08:32]

• Consequences of Poor Prep:
  Poor bowel prep may necessitate repeating the colonoscopy earlier than the default 10 years, reducing the test’s effectiveness and causing extra burden for the patient [08:32].

4. Colonoscopy Technique & High-Risk Areas

• Blind Spots and Critical Areas:
  • Ileocecal valve
  • Right-sided colon/cecum: High risk for flat, sessile serrated lesions
  • Hepatic flexure (the ‘blind spot’)
• Best Practices:
  • Multiple careful passes over high-risk areas (e.g., 2–3 times at hepatic flexure)
  • Dedicated time for withdrawal (≥8–10 min withdrawal time recommended)

  “Our metrics, our quality metrics are always sort of improving. Now we're trying to hit at least 10 minutes, 8 to 10 minutes on withdrawal ... these lesions can be very small and very flat and very easy to miss.” — Dr. Sith Saker [09:38]

5. Pearls and Take-Home Points

RTL Pearls by Dr. Saker [11:28]:

• Always obtain a detailed family history—including polyp pathology when possible.
• Advanced adenomas (as defined) in a first-degree relative confer the same risk as colon cancer (screen at age 40 or 10 years prior to relative’s diagnosis).
• Colonoscopy is both diagnostic and preventive, but the best strategy is the one the patient will complete.

  “The best strategy is the one that the patient is going to follow.” — Dr. Sith Saker [12:57]

• Any positive stool-based test must prompt a diagnostic colonoscopy.

Navin’s Closing Thought [12:57]:

“The ability to screen for colon cancer is so, so important ... the best screening strategy is the one that your patient is going to follow through with.”

Notable Quotes & Moments

• On risk stratification and family history:
  “Always think about advanced polyps as the same as colon cancer.”
  — Dr. Sith Saker [02:00]
• On the importance of prep:
  “It just sort of makes the whole procedure much more comfortable ... if the preparation is not great, sometimes we have to repeat the colonoscopy ...”
  — Dr. Sith Saker [08:32]
• On the best screening test:
  “If they're reluctant to get a colonoscopy but will undergo stool testing, I think it's important to discuss that with them ... the best strategy is the one that the patient is going to follow.”
  — Dr. Sith Saker [11:28, 12:57]

Useful Timestamps

• 01:02 – Episode kickoff, guest introduction
• 02:00 – Family history and risk stratification
• 04:31 – Discussion of screening methods
• 06:32 – CT colonography: special cases
• 07:31 – Bowel preparation protocols
• 08:32 – Impact of prep quality
• 09:38 – High-risk anatomical areas in colonoscopy
• 11:28 – Pearls and summary

Final Takeaway

This episode provides a comprehensive, pragmatic overview of colorectal cancer screening, balancing concise guideline-based advice with real-world insights on patient adherence and procedural quality. Key message: Know your patient's true risk, choose a screening approach they will follow, and uphold high standards for colonoscopy quality to maximize preventive benefit.