Colorectal Cancer Awareness Issue 2019
26.Februar 2019 (online)
Awareness of the importance of colorectal cancer (CRC) screening is increasing worldwide. In Europe, population-based CRC screening programs are underway in 15 of 28 countries . While this proportion may appear disappointing, it is a significant improvement from 2007 when only five countries were implementing programs . The US shows a similar picture, with 63 % of adults between the ages of 50 and 75 receiving CRC screening based on recent guidelines; the aim is to increase participation to over 70 % in 2020 .
Since February 2000 when US President Clinton officially dedicated March as CRC Awareness Month, thousands of survivors, patients, and medical professionals have raised awareness of CRC. They have highlighted the importance of taking up screening in order to reduce CRC incidence and related illness and mortality, through early detection of precancerous polyps and of CRC itself.
Endoscopy has regularly devoted its March issue to CRC Awareness Month since 2014. This month Endoscopy also presents important new research on the prevention, diagnosis, and treatment of precancerous colorectal lesions and CRC.
Two randomized controlled trials (RCTs) investigate conditions that might further improve the quality of colonoscopy. The effect of low volume bowel preparation on participation levels was studied in the Polish Colonoscopy Screening Program, with disappointing results – no impact on participation or lesion detection rates was found.
In another study, of routine colonoscopies, no differences in lesion detection rates were found between different endoscopy systems, and between conventional colonoscopy, high definition, and/or virtual chromoendoscopy. Both studies highlight efforts to improve the quality of colonoscopy, but conclude that at a certain quality level it is hard to establish further improvement.
Optical diagnosis can replace histopathology for diminutive (1 – 5 mm) colorectal polyps, if certain quality criteria are met. Moreover, cold snare polypectomy is now advocated as the method of choice for resecting diminutive polyps as it reduces delayed bleeding compared to hot snare polypectomy. Three studies in this issue discuss various questions related to diagnosis and treatment of diminutive and small (6 – 9 mm) polyps.
The first study assessed whether small (6 – 9 mm) polyps can be included in optical diagnosis strategies. It was concluded that this inclusion improves the efficacy of such strategies while maintaining performance thresholds. Nonetheless, there is a small risk (< 0.5 %) of missing T1 cancers when small polyps are included in the optical diagnosis strategy.
A study from the US investigated whether diminutive polyps, especially those ≤ 3 mm in size and resected during colonoscopy are sometimes histologically misinterpreted as normal tissue. The authors found that pathologists diagnosed normal mucosa in around 16 % of ≤ 3-mm endoscopically diagnosed adenomas and concluded that pathology interpretation should not always be the gold standard for lesion management. This statement is challenged in an accompanying editorial by Drs. Vieth & Neurath. A study from Japan examined whether cold forceps polypectomy (CFP) could be used to remove diminutive colorectal polyps, and found that indeed there was a low local recurrence rate after CFP, especially for lesions ≤ 3 mm in size.
How will colonoscopy be performed in the (near) future? We can expect that computer technology will increasingly help us to recognize and characterize lesions in the colorectum. In a pilot study from Spain, a computational histology prediction system, based on colorectal polyp surface texture patterns and using high definition white light images, was evaluated and found to have results comparable to endoscopist assessment. Based on this and other studies, computer-aided diagnosis (CAD) systems will likely play an important role in endoscopic practice.
A joint guideline from the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Digestive Oncology (ESDO) completes this CRC issue, providing guidance on the use of colonoscopy surveillance after surgery for CRC and after complete endoscopic resection of early CRC.
Don’t miss out on the latest developments in colonoscopy, polyp management, and colorectal cancer during the 2019 Awareness Month. Enjoy reading!
Peter D. Siersema
on behalf of the Editors
- 1 Basu P, Ponti A, Anttila A. et al. Status of implementation and organization of cancer screening in The European Union Member States – Summary results from the second European screening report. Int J Cancer 2018; 142: 44-56
- 2 NIH National Cancer Institute. Cancer trends progress report. Colorectal cancer screening. https://progressreport.cancer.gov/detection/colorectal_cancer Accessed: 14 Jan 2019