Issue 4 - August 2010 - Pacini Editore

164
role of endoscopy for polypoid
and non-polypoid colonic lesions
L.H. Eusebi, F. Bazzoli
Department of Internal Medicine and Gastroenterology, University
of Bologna, Italy
Colorectal cancer (CRC) is the third most common cancer
diagnosed in men and women and a leading cause cancer-related
death worldwide. Declining rates in CRC incidence and
mortality have been revealed by recent trends, due to reduced
exposure to risk factors, screening’s effect on early detection
and prevention of neoplastic and pre-neoplastic lesions, and
improved treatment.
Most colorectal cancers are believed to evolve through adenoma-carcinoma
sequence; therefore, the goal of CRC screening
is to reduce mortality through a reduction in incidence of advanced
disease. Indeed, CRC screening can achieve this goal
through the detection of adenomatous polyps and of earlystage
adenocarcinomas, followed by endoscopic resection of
such lesions.
Screening programs are based on patients risk stratification,
evaluating their personal, familial and clinical history. Indeed,
identifying high risk patients, such as those with a family or
personal history of CRC or adenomatous polyps, inflammatory
bowel disease or of genetic syndromes such as Hereditary
Non Polyposic Colorectal Cancer (HNPCC) and Familial
Adenomatous Polyposis (FAP), allows to determine the most
adequate screening strategy.
Among the available screening techniques, several aspects
underline the advantage of endoscopy; indeed, colonoscopy
is the only single-stage strategy not requiring pretesting and
polyps can be removed immediately during the screening
procedure; besides, all other forms of screening, if positive,
require colonoscopy as a second procedure 1 .
The long term colorectal cancer incidence and mortality reduction
provided by endoscopic polypectomy has been confirmed
by the findings of the National Polyps Study. Indeed, in this
study, patients with adenomas who had undergone endoscopic
resection experienced a 76-90% reduction in CRC incidence
compared with the expected general population incidence 2 .
Other case-control and cohort studies have reported lower risk
reduction rates of CRC after therapeutic colonoscopy than the
National Polyp Study. Indeed, although endoscopy has a major
protective role against colorectal cancer, colonoscopy is not an
infallible “gold standard” and colonic lesions might still develop
despite surveillance screening; detection miss-rates vary
from 27% for adenomas < 5 mm to about 2% for CRC 3 4 .
Several reasons might explain the imperfect colonoscopy
protection such as the presence of rapidly growing tumours
(HNPCC, increased risk of microsatellite instability in “interval”
cancers), ineffective polypectomy, incomplete bowel
preparation or ineffective application of current colonoscopic
detection technologies 5 .
Therefore, quality indicators and targets for colonoscopy,
such as bowel preparation quality, cecal intubation rate, mean
5 th triennial congress of the italian society of anatomic Pathology and diagnostic cytoPathology
Thursday, September 23 rd , 2010
Colon neoplasms
Moderators: G. Lanza (Ferrara), M. Risio (Torino)
colonoscopic withdrawal time, polyp detection rate and adverse
or unplanned events occurring within 24 hours of colonoscopy,
have been suggested to improve the effectiveness of
the endoscopic inspection 6 .
Furthermore, an underlying principle of quality improvement
in colonoscopy is that such quality indicators must be
recorded and monitored during examination.
In Emilia-Romagna, CRC screening started in 2005 and since
then more than 1000000 people have been involved, about one
third of the adult population. Among people that were positive
at the Faecal Occult Blood Test, 79% underwent colonoscopy.
During endoscopic examination, 16% of patients were
diagnosed with non-advanced adenomas, 32% with advanced
adenomas and in 6% of cases CRC was found.
Finally, although recent trend confirm increasing rates of patients
applying to the screening programs and distribution of
colorectal cancer stages has shifted towards earlier stages, in
the near term, even greater incidence and mortality reductions
could be achieved if a greater proportion of adults received
regular CRC screening.
references
1 Levin B, Lieberman DA, McFarland B, et al. Screening and surveillance
for the early detection of colorectal cancer and adenomatous
polyps, 2008: a joint guideline from the American Cancer Society, the
US Multi-Society Task Force on Colorectal Cancer, and the American
College of Radiology. CA Cancer J Clin 2008;58:130-60.
2 Winawer SJ, Zauber AG, Ho MN, et al. Prevention of colorectal
cancer by colonoscopic polypectomy. The National Polyp Study Workgroup.
N Engl J Med 1993;329:1977-81.
3 Rex DK, Cutler CS, Lemmel GT, et al. Colonoscopic miss rates of adenomas
determined by back-to-back colonoscopies. Gastroenterology
1997;112:24-8.
4 Bressler B, Paszat LF, Vinden C, et al. Colonoscopic miss rates for
right-sided colon cancer: a population-based analysis. Gastroenterology
2004;127:452-6.
5 Rex DK, Eid E. Considerations regarding the present and future roles
of colonoscopy in colorectal cancer prevention. Clin Gastroenterol
Hepatol 2008;6:506-14.
6 Lieberman D, Nadel M, Smith RA, et al. Standardized colonoscopy reporting
and data system: report of the Quality Assurance Task Group
of the National Colorectal Cancer Roundtable. Gastrointest Endosc
2007;65:757-66.
Histology quality assurance of neoplastic
colorectal lesions
P. Cassoni, A. Cassenti, P. Cardone, I. Castellano, M. Risio *
Department of Biological Sciences and Human Oncology, University
of Turin; * IRCC, Candiolo, Italy
The diagnostic agreement on the neoplastic lesions of the colorectum
may be affected by several factors, including lack of
standardization in terminology, and objective diagnostic “grey
areas”. The recent publication of the European guidelines for
pathology quality assurance in colorectal cancer screening
represented a robust attempt in limiting diagnostic discordance,
and outlined the major criteria which should be adopted
in order to achieve a good diagnostic agreement in key