Related Experiment Video
Updated: Jun 10, 2026
06:46
Competing-Risk Nomogram for Predicting Cancer-Specific Survival in Multiple Primary Colorectal Cancer Patients after Surgery
Published on: September 27, 2024
Non-polypoid colorectal neoplasms are relatively common worldwide
Ana Ignjatovic1, Brian P Saunders
1Wolfson Unit for Endoscopy, Imperial College, St Mark's Hospital, Watford Road, Harrow, HA1 3UJ, London, UK.
Gastrointestinal Endoscopy Clinics of North America
|July 27, 2010
Summary
Flat adenomas are common, but flat colorectal cancers are rare (5-10% of colonoscopies). Flat lesions with depression pose a significant malignancy risk, potentially preceding small, flat cancers.
Area of Science:
- Gastroenterology
- Oncology
- Endoscopy
Background:
- Flat adenomas are frequently detected during colonoscopies globally.
- Small, flat, submucosally invasive colorectal cancers are uncommon, representing 5-10% of cancers found during colonoscopy.
- Defining flat lesions consistently is challenging, leading to study variations.
Purpose of the Study:
- To investigate the characteristics and malignant potential of flat colorectal neoplasms.
- To differentiate between flat elevated lesions and flat lesions with depression.
- To clarify the role of flat lesions as precursors to colorectal cancer.
Main Methods:
- Review of existing literature on flat colorectal neoplasms.
- Analysis of colonoscopy findings and pathological reports.
- Comparison of flat lesion definitions and their impact on reported frequencies.
Main Results:
- Flat elevated lesions are common and have a low risk of malignancy.
- Flat lesions with depression are associated with a significant risk of malignancy.
- These depressed flat lesions may be precursors to small, flat, or ulcerating cancers.
Conclusions:
- Flat lesions with depression represent a high-risk group for colorectal cancer development.
- Standardized definitions are needed for accurate assessment of flat colorectal neoplasms.
- Early identification and management of depressed flat lesions are crucial for cancer prevention.
Related Concept Videos
01:27Diverticular Disease of the Colon
Diverticular disease involves the formation of diverticula—small sac-like outpouchings of the colonic wall—and their complications. It most commonly affects the sigmoid colon due to higher intraluminal pressure and structural vulnerability. It results from structural weakness and increased pressure in the colon, producing pseudodiverticula that may remain silent or progress to inflammation and serious complications.Structure of DiverticulaIn diverticulosis, these outpouchings are...
02:23Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
02:21Cancers Originate from Somatic Mutations in a Single Cell
Cancer arises from mutations in the critical genes that allow healthy cells to escape cell cycle regulation and acquire the ability to proliferate indefinitely. Though originating from a single mutation event in one of the originator cells, cancer progresses when the mutant cell lines continue to gain more and more mutations, and finally, become malignant. For example, chronic myelogenous leukemia (CML) develops initially as a non-lethal increase in white blood cells, which progressively...
01:25Assessment of the Rectum and Anus
Evaluating the rectum and anus plays a crucial role in conducting a thorough physical examination of the gastrointestinal system. Although it may be uncomfortable and often embarrassing for the patient, it holds immense diagnostic value, particularly in detecting gastrointestinal diseases and abnormalities. This guide will explain how to perform this assessment using inspection and palpation methods.
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
01:25Endoscopic Procedures II: Colonoscopy
The colon, or large intestine, is the final segment of the digestive system. Its primary functions include absorbing water and vitamins produced by gut bacteria and transforming waste from liquid to solid to form stool. In adults, the large intestine is approximately 5 feet long and consists of four main sections:
03:18Non-LTR Retrotransposons
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...