Colon Cancer
Everything in the library about colon cancer — built automatically from the recorded discussions that name it
Educational content from recorded physician discussions — not medical advice. Always talk to your child's care team about your child's situation.
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In-Depth Reviews
4 items
Colon Cancer with Conor Delaney
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Dr. Ponsky, professor of surgery at the Cleveland Clinic Lerner College of Medicine and Department of Surgery and Dr. Colon Delaney, chairman of digestive disease and institute and professor of surgery at Cleveland Clinic Lerner College of
podcast26:50 · Dec 2020
Colorectal Cancer
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An interactive discussion about colorectal cancer between Jeffrey Ponsky, MD and Conor Delaney, MD, PhD. Dr. Delaney, is the chairman of the Digestive Disease
podcast26:42 · Jul 2026
Colorectal Cancer
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An interactive discussion about colorectal cancer between Jeffrey Ponsky, MD and Conor Delaney, MD, PhD. Dr. Delaney, is the chairman of the Digestive Disease
podcast26:42 · Jul 2026
Colorectal Cancer
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An interactive discussion about colorectal cancer between Jeffrey Ponsky, MD and Conor Delaney, MD, PhD. Dr. Delaney, is the chairman of the Digestive Disease and Surgery Institute at Cleveland Clinic, Cleveland, OH. Dr. Delaney is also a p
podcast26:42 · Jul 2026
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Every expert statement below comes from the recorded discussions, with its speaker and moment.
Colon Cancer with Conor Delaney
Colonoscopy is still the best test for colon cancer detection, finding the vast majority of cancers and polyps, though not perfect.
clinicalConor Delaney1:16 ↗
Serrated adenomas (previously misclassified as hyperplastic polyps, particularly large ones in the right colon) have genetic predisposition, tie into family cancer syndromes, and carry very high cancer risk.
clinicalConor Delaney2:05 ↗
Finding serrated adenomas requires family assessment for hereditary cancer syndromes and may necessitate changes in colonoscopy frequency and family member screening.
guidelineConor Delaney2:42 ↗
Serrated polyps can be flat and difficult to visualize; retroflexion in the cecum is increasingly used because they are often on the inferior or superior side of folds.
clinicalConor Delaney3:27 ↗
For rectal cancer, distal margin requirements are 5 cm if achievable, 2 cm if necessary, and 1 cm for very low tumors as long as they are not poorly differentiated.
clinicalConor Delaney6:13 ↗
The measurement '6 centimeters from the anal verge' varies significantly by patient body habitus and can represent different anatomical locations (anorectal ring vs. near dentate line).
clinicalConor Delaney7:25 ↗
Distant staging for rectal cancer is best performed with CT abdomen (for liver metastases) and CT chest (replacing chest X-ray per current guidelines).
guidelineConor Delaney9:31 ↗
MRI has become the standard for local staging of rectal cancer, with high-resolution, high-Tesla magnets using standardized protocols developed by Bill Heald and Gina Brown at the Royal Marsden.
clinicalConor Delaney9:50 ↗
MRI is 90 to mid-90s percent accurate for T-staging and high 80s to 90% accurate for nodal staging of rectal cancer.
clinicalConor Delaney13:37 ↗
Endoscopic ultrasound is only about 70% accurate for predicting nodal involvement in rectal cancer and is much more operator-dependent than MRI.
clinicalConor Delaney13:56 ↗
MRI is particularly good at distinguishing T3 and T4 tumors and assessing circumferential resection margins, though less accurate at distinguishing T1 from T2.
clinicalConor Delaney10:27 ↗
Historical local recurrence rates for rectal cancer from good institutions were 20–38%, with some series up to 50%.
epidemiologicalConor Delaney10:51 ↗
With optimized surgery and imaging, local recurrence rates for rectal cancer should now be under 10%; Cleveland Clinic's rate over the last 10 years was about 3%.
epidemiologicalConor Delaney11:04 ↗
Circumferential resection margin is the most important margin (or many think more important than distal margin) for preventing local recurrence in rectal cancer.
clinicalConor Delaney10:39 ↗
Total mesorectal excision (TME) can be performed with about 5 mL of blood loss because it follows a bloodless embryological plane; bleeding indicates wrong plane unless deliberately outside TME plane.
clinicalConor Delaney12:24 ↗
Neoadjuvant therapy for rectal cancer is indicated for T3 tumors (outside the rectal wall) or node-positive disease.
guidelineConor Delaney12:54 ↗
Stage 1 rectal cancer (node-negative, T1 or T2), particularly in the upper third of the rectum, does not require neoadjuvant therapy.
guidelineConor Delaney13:18 ↗
Short-course radiation (5×5 Gy over 5 days, surgery 1–2 weeks later) is commonly used in Europe; long-course chemoradiation (40–45 Gy over 6 weeks with 6–8 week wait) is standard in the US.
guidelineConor Delaney18:04 ↗
25 Gy over a short period is radiotherapeutically equivalent to 40–45 Gy over a longer period, but long-course therapy may produce better tumor downstaging for bulky tumors.
clinicalConor Delaney18:26 ↗
Transanal resection for rectal cancer is generally limited to T1 tumors less than one-third circumference and ideally less than 2 cm.
guidelineConor Delaney14:35 ↗
Historical local recurrence rates for transanally excised rectal cancers were about 18%, remarkably consistent across multiple centers.
epidemiologicalConor Delaney14:51 ↗
Transanal endoscopic microsurgery (TEM) may produce better outcomes than traditional transanal excision, though it is unclear whether this is due to technology or improved surgical understanding.
opinionConor Delaney15:05 ↗
For young, curable patients, radical resection is generally favored over transanal resection; transanal resection is typically reserved for patients unfit for radical surgery or those who would require permanent stoma.
guidelineConor Delaney15:27 ↗
For rectal cancer, full-thickness excision is required; ESD or EMR is never appropriate for proven cancer, only for benign polyps.
clinicalConor Delaney16:24 ↗
For colon cancer, at least 12 lymph nodes are required for adequate staging, though many surgeons aim for at least 16.
guidelineConor Delaney19:51 ↗
High ligation of the inferior mesenteric artery (above the takeoff of the left colic artery) is standard for sigmoid colectomy, with protection of autonomic nerves to preserve sexual function.
clinicalConor Delaney19:59 ↗
Total mesocolic excision for colon cancer should be performed with about 5 mL of blood loss in the embryological plane between retroperitoneal peritoneum (Toldt's fascia) and mesocolic peritoneum.
clinicalConor Delaney20:18 ↗
Scandinavian data showed local recurrence rates for colon cancer were even higher than for rectal cancer (high 20s%) before focus on complete mesocolic excision technique.
epidemiologicalConor Delaney20:48 ↗
For cecal or ileocecal valve tumors, 10 cm of small bowel should be resected; for mid-ascending colon tumors, 5 cm of small bowel is adequate.
clinicalConor Delaney23:12 ↗
Extracorporeal stapled anastomosis for right hemicolectomy achieved a leak rate of 0.8% over 1000 cases at Cleveland Clinic.
epidemiologicalConor Delaney24:00 ↗
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