Transcript History of CRC Screening

Optimizimg Colorectal
Cancer Screening and
Surveillance
Thomas B. Hargrave M.D
November 3, 2012
CRC: Overview
• Colorectal cancer is the third most common
cancer in California, estimated 14,415 cases in
2005
• The second deadliest cancer in men and women
5210 deaths in 2005 (breast 4060; lung 14,450)
• The incidence of CRC has been declining over
the last 2 decades
• Screening for colonic adenomas appears to
significantly reduce the incidence of and risk of
dying from colorectal cancer
Projected Annual Hospital Admissions for
Colon Cancer in the US: 1990-2050
Number of admissions (thousands)
Year
Seifeldin and Hantsch, Clin Ther 1999; 21: 1370
CRC Risk Factors
Colorectal Cancer
Sporadic (average risk)
(65%–85%)
Family
history
(10%–30%)
Rare
syndromes
(<0.1%)
Familial adenomatous
polyposis (FAP) (1%)
Hereditary nonpolyposis
colorectal cancer
(HNPCC) (5%)
CENTERS FOR DISEASE CONTROL
AND PREVENTION
HNPCC – Clinical Features
• Suspect HNPCC if two relatives with colon,
one under the age of 50
• Modified Amsterdam Criteria (3-2-1 Rule)
– 3 relatives with HNPCC related cancer
(CRC, uterine, small bowel, renal pelvis or ureter)
– 2 generations affected
– 1 person diagnosed at age < 50 y
– 1 person is a first degree relative of the other two
• HNPCC should be screened every one to three
years beginning between the ages of 20 and 25.
Vasen et al, Gastroenterology 1999; 116: 1453
Rationale for Screening
Rationale for Screening
• Most CRC are slow growing with a doubling time
of approximately 600 days
• Estimated 75-80% of colon cancers develop from a
polypoid adenoma (>10 years) “Polyp-Cancer
Sequence”
• Removal of advanced adenomas (over 10 mm, or
associated with villous features) reduces the
incidence of invasive CRC
• Cancers discovered by screening tend to be less
advanced and associated with greater probability
of curative resection
Benefits of Screening: Earlier Stage
= Improved Survival
Distribution of Cancer Stages at Time
of Diagnosis: 1999-2006
American Cancer Society Facts and Figures 2012
Flexible Sigmoidoscopy in the Randomized
Prostate, Lung, Colorectal, and Ovarian
(PLCO) Cancer Screening Trial
• Of 77 447 enrollees, 67 073 (86.6%) had at least
one FSG and 39 443 (50.9%) had two FSGs.
• Repeat FSG increased colorectal cancer or
advanced adenoma detection in women by onefourth and in men by one-third
• Of 223 pts who received a diagnosis of
colorectal carcinoma within 1 year of a positive
FSG, 64.6% had stage I and 17.5% had stage II
disease ( i.e. 82% localized disease)
J Natl Cancer Inst. 2012;104(4):280-289
2012 CRC Screening and
Surveillance Guidelines
CRC Screening Options: Average Risk
• In 2008 two important CRC screening
guidelines were published:
– American Cancer Society and the US MultiSociety Task Force with the American
College of Radiology
– US Preventative Services Task Force
(USPSTF)
• The USPSTF recently updated
surveillance guidelines in August 2012
CRC Screening Options: Average Risk
USPSTF
• Annual screening with high-sensitivity
FOBT
– FIT vs guaiac-based tests
• Sigmoidoscopy every 5 years with high
sensitivity FOBT every 3 years
• Colonoscopy every 10 years
• Insufficient evidence
– CT colonography
– Fecal DNA
- ACBE
CRC Screening Options: Average Risk
ACS and Multi-Society Task Force
• Annual screening with high-sensitivity
FOBT
– FIT vs guaiac-based tests
• Sigmoidoscopy every 5 years with high
sensitivity FOBT every 3 years
• Colonoscopy every 10 years
• Double contrast BE every 5 years
• CT colonography (CTC) every 5 years
Family History of Colon Cancer
• Single first-degree relative with CRC or advanced
adenoma (adenoma 1 cm in size, or with high-grade
dysplasia or villous elements) diagnosed over age 60
years.
– Recommended screening: same as average risk
(colonoscopy every 10 years beginning at age 50 years)
• Single first-degree relative with CRC or advanced
adenoma diagnosed at age <60 years or two firstdegree relatives with CRC or advanced adenomas.
– Recommended screening: colonoscopy every 5 years
beginning at age 40, or 10 years younger than age at
diagnosis of the youngest affected relative
Cumulative Probabilities of CRC Based on Adenoma
Histology and the Presence or Absence of Surveillance.
Gut. 2012;61(8):1180-1186
2012 Consensus Update by the USPSTF on
Colorectal Cancer Surveillance
Baseline colonoscopy:
most advanced
finding(s)
Recommended
surveillance interval (y)
Quality of evidence
supporting the
recommendation
New evidence stronger
than 2006
No polyps
10
Moderate
Yes
Small (<10 mm)
hyperplastic polyps in
rectum or sigmoid
10
Moderate
No
1–2 small (<10 mm)
tubular adenomas
5–10
Moderate
Yes
3–10 tubular adenomas
3
Moderate
Yes
>10 adenomas
<3
Moderate
No
One or more tubular
adenomas ≥10 mm
3
High
Yes
One or more villous
adenomas
3
Moderate
Yes
Adenoma with HGD
3
Moderate
No
2012 Consensus Update by the USPSTF on
Colorectal Cancer Surveillance
Baseline colonoscopy:
most advanced
finding(s)
Recommended
surveillance interval (y)
Quality of evidence
supporting the
recommendation
New evidence stronger
than 2006
Sessile serrated
polyp(s) <10 mm with
no dysplasia
5
Low
NA
3
Low
NA
1
Moderate
NA
Sessile serrated
polyp(s) ≥10 mm or
Sessile serrated polyp
with dysplasia or
Traditional serrated
adenoma
Serrated polyposis
syndromea**
** 1) at least 5 serrated polyps proximal to sigmoid, with 2 or more ≥10 mm; (2) any serrated polyps proximal to
sigmoid with family history of serrated polyposis syndrome; and (3) >20 serrated polyps of any size throughout the
colon.
Sessile Serrated Polyps
Sessile Serrated Polyps
• Serrated polyps are distinct from conventional
adenomas and represent a heterogeneous group of
polyps with varying histology and malignant potential
• Certain serrated polyps may be precursors for
colorectal cancers that develop via a "serrated polyp
pathway“
• Molecular markers suggest a link between SSPs and
colorectal cancers characterized as having a CpG
island methylator phenotype (CIMP)
• Precursors of CIMP-positive colorectal cancer, such as
SSPs, have been proposed to have a particularly
important role in proximal colon cancer development.
Serrated Adenomas Can be
Difficuly to Identify
Look for the mucous cap
Sessile Serrated Adenoma with
Focus of HGD
Colonoscopy May Not Reduce the
Incidence of Sessile Serrated Polyps
• Group Health-based study population included 213
advanced adenoma cases, 172 SSP cases, and 1,704
controls aged 50–79 years, who received an index
colonoscopy from 1998–2007
• Previous colonoscopy was inversely associated with
advanced adenomas in both the rectum/distal colon
(OR=0.38; 95% CI: 0.26–0.56) and proximal colon
(OR=0.31; 95% CI: 0.19–0.52), but
• There was no statistically significant association between
previous colonoscopy and the incidence of SSPs
Am J Gastroenterol. 2012;107(8):1213-1219
Logistic Regression Analyses of the Assoc. Between
Previous Colonoscopy, Advanced Adenomas (AA),
and Sessile Serrated Polyps (SSP)
Am J Gastroenterol. 2012;107(8):1213-1219
So Which Screening Test
Is Best for Average Risk
Patients?
“The best test is the
one that gets done.”
John M. Inadomi, M.D. N Engl J Med 2012
Use of Colonoscopy and Flexible Sigmoidoscopy
Among Medicare Fee-for-Service Beneficiaries
Procedures per 100 000 beneficiaries from a piecewise linear regression model.
JAMA. 2006;296:2815-2822.
Screening Colonoscopy : Statistics
• The use of colonoscopy for screening has
increased steadily over the last decade
• Estimates 15 million colonoscopies performed
each year in US
• No randomized, controlled trials have tested
whether colonoscopy reduces the incidence of
colon cancer.
• Support for the role of colonoscopy in CRC
prevention derives entirely from indirect
evidence and observational studies
• Only 50% of eligible adults screened
• CRC
screening
data from
Centers for
Disease
Control and
Prevention
Office of Surveillance, Epidemiology, and Laboratory Services.
Behavioral Risk Factor Surveillance System : January 10, 2012
California Dept of Health Services 2003
Adults Over 50 Who Have Had a
Sigmoidoscopy/Colonoscopy within 5 Years
Which CRC Screening
Approach is Most CostEffective?
Markov Model: Estimated Reductions in
CRC Deaths for Various Screening Protocols
Gastroenterology 2005;129:1151-62
Estimated Cost Per Life-Year Gained
Compared With Natural History
This is the Kaiser rationale
for the use of annual FIT
over colonoscopy 2007
Gastroenterology 2005;129:1151-62
CRC Screening for Average-Risk
Canadians: An Economic Evaluation
• Cost-utility analysis using a Markov model was
performed comparing guaiac-based fecal occult blood
test (FOBT) or fecal immunochemical test (FIT)
annually, fecal DNA every 3 years, flexible
sigmoidoscopy or computed tomographic colonography
every 5 years, and colonoscopy every 10 years
• Adenoma and CRC prevalence rates were based on a
recent systematic review whereas screening adherence,
test performance, and CRC treatment costs were based
on publicly available data
• Three distinct FIT testing strategies were considered, on
the basis of studies that have reported “low,” “mid,” and
“high” test performance characteristics
Heitman S, et al PLoS Med 2010; DOI: 10.1371
CRC Screening for Average-Risk
Canadians: An Economic Evaluation
Colonoscopy appeared to be the most effective screening
strategy if FIT adherence to the annual schedule was
40% or less, instead of the base-case assumption of 63%
Heitman S, et al PLoS Med 2010; DOI: 10.1371
Colonoscopic Polypectomy is the Therapeutic
“Tip of the Spear” of CRC Prevention
Positive FDNA
Positive F.I.T
Positive FOBT
Positive FS
Colonoscopy
Surveillance
Virtual CTC
Family History
DC Ba. Enema
CRC Screening: How Well
Does It Actually Work?
Screening Colonoscopy Efficacy
• Although the National Polyp Study suggested
that colonoscopic polypectomy reduced
subsequent cancer risk by 70-90%, real-world
studies indicate significantly less efficacy
• Population studies from Germany and Canada
have reported reductions of as low as 30% to
50%.
• The ability of colonoscopy to reduce proximal
colon cancer appears significantly less than
distal cancers
Retrospective Analysis from the National Polyp Study (NPS):
Removal of Adenomatous Polyps Associated with a 53%
Reduction in CRC Mortality: Mean Follow-up of 15.8 years.
Zauber AG et al. N Engl J Med 2012;366:687-696
Cancer Reduction with
Colonoscopy: Proximal << Distal
Study
Odds ratio
Distal Cancers
Odds ratio
Proximal cancer
Canada 2009 (1)
0.33
0.99
Germany 2010 (2)
0.29
0.99
California 2004 (3)
0.16
0.67
Germany 2011 (4)
0.16
0.44
1) Annals Int Medicine 2009;150:1-8
3) Gastroenterology 2004;127:452–456
2) Journal of the National Cancer Institute 2010; 102: 89 – 95.
4) Ann Intern Med. 2011:154;22-30
Prox. and Distal CRC Resection Rates in US
Since Widespread Screening by Colonoscopy
• Nationwide Inpatient Sample (NIS), the largest
all-payer inpatient care database in the US (5-8
million hospital stays per year)
– Study of all inpatient discharges for surgical resection
of CRC 1993-2009
• For persons age 50 years and older, overall CRC
resection rates decreased 33.5% from 1993 to 2009
• In contrast, the overall CRC resection rates
increased by 1.3% per year for persons aged 40–
49 years and by 2.4% per year for persons aged
18–39 years from 1993 to 2009
Gastroenterology 2012;143(5):1227-1237
Gastroenterology 2012;143(5):1227-1237
Proximal and Distal CRC Resection Rates in US
Since Widespread Screening by Colonoscopy
Medicare coverage for FOBT/FS for
average risk persons & colonoscopy
for high risk
Medicare coverage for colonoscopy
screening for average risk persons
Gastroenterology 2012;143(5):1227-1237
65% CRC Reduction May Be Best
We Can Achieve
• 715 patients with screening and surveillance
colonoscopies 1989-2003 (Univ. Indiana)
• 10,492 patient years of follow-up
– Doctors, dentists, nurses and spouses
– 95% White
• 12 cases of colon cancer/ 3 cancer deaths at
average of 8 years of follow-up
– 8/12 (66%) cancers in proximal colon.
• 67% reduction in cancer incidence
• 65% reduction in cancer death
Clin Gastro Hep 2009;7;770-775
Interval Colon Cancers
• Interval cancers: CRC diagnosed within 6-36
months of a baseline examination negative for
neoplasia ( i.e. presumed missed on colonoscopy)
• Up to 9% of CRC in a Canadian registry were
interval cancers Gastroenterology 2011;140:65–72
• SEER medicare database 1994-2005: 7.2% of
CRC were interval cancers Annals Gastro 2012 25:1-3
• Several studies have suggested that pts who
develop interval CRC after colonoscopy are more
likely to have proximal compared than distal
cancers
Possible Reasons for Why
Colonoscopy Protection is Imperfect
• Multiple explanations for interval cancers have
been proposed,
– Missed lesions during the initial colonoscopy,
– Incomplete adenoma removal,
– Development of rapidly growing new lesions
– Failed detection of cancer despite biopsy.
– Poor bowel preparation
• Tumor biology (sessile, serrated adenomas,
microsatalite instability)
Variable Physician Endoscopic Skills
• Physician: Procedural/motor skill deficits
• Incomplete colonoscopy,
• Incomplete/inadequate polypectomy,
• Withdrawal technique
• Physician’s limitations
– Perceptual factors (e.g., variation in color and depth
perception)
– Personality characteristics (e.g., conscientiousness,
obsessiveness, impulsivity)
– Knowledge and attitude deficits (e.g., awareness and
appearance of flat lesions)
Adenoma Detection Rate Predicts
Subsequent Cancer Risk
• Multivariate Cox proportional-hazards regression model
to evaluate the influence of quality indicators for
colonoscopy on the risk of interval cancer.
• Data were collected from 186 endoscopists who were
involved in a colonoscopy-based colorectal-cancer
screening program involving 45,026 subjects
• A total of 42 interval colorectal cancers were identified
during a period of 188,788 person-years.
• The endoscopist's rate of detection of adenomas was
significantly associated with the risk of interval colorectal
cancer (P=0.008)
Kaminski MF et al. N Engl J Med 2010;362:1795-1803.
Cumulative Hazard Rates for Interval Colorectal Cancer,
According to the Endoscopist's Adenoma Detection Rate (ADR)
Kaminski M et al. N Engl J Med 2010;362:1795-1803
Variation in Adenoma Detection Rates
Between Gastroenterologists
• Consecutive colonoscopy reports performed by nine
attending gastroenterologists at Indiana University
Hospital between January 1999 and January 2004
• Among patients 50 yr of age, the range of detection of
at least one adenoma per colonoscopy by nine
colonoscopists was 15.5–41.1%,
– At least two adenomas was 4.9–20.0%,
– At least three adenomas was 0.8–10.8%, and
– At least one adenoma 1.0 cm was 1.7–6.2%, and
• The range of adenomas detected per colonoscopy was
0.21–0.86. (p<0.001)
American Journal of Gastroenterology (2007) 102, 856–861
Variation in Adenoma Detection Rates
Between Gastroenterologists
• 550 consecutive screening colonoscopies,
average risk individuals
• 10 BC GI at a tertiary academic institution
• 121 (22%) had at least one adenoma
• Adenoma detection rate per colonoscopy 0.090.82 (a nine-fold range)
• Mean withdrawal time 7 min (3.4-9.6)
• Significant inverse relationship between cecal
intubation time, withdrawal time, and
adenoma detection (p<0.01)
GIE 2008:67(5):AB294
True and Mean Prevalence of
Adenomas and ADRs
% of
screened
patients
with
adenomas
True
prevalence
of
adenomas
Mean
published
ADR for
males
Mean
published
ADR for
females
Target
ADR
males
Target
ADR
females
>50%
32%
20%
25%
15%
Missed Adenomas
Missed Adenomas
• Tandem colonoscopy studies have demonstrated
adenoma miss rates of 21% to 24%
• Some investigators have suggested that the true
miss rate could be even higher because the same
technology was used twice, and lesions behind folds
or flexures could be missed during both
procedures.
• Pickhardt et. al . mapped locations of adenomas
missed by colonoscopy but detected by CT
colonography and found that 67% were on the
proximal aspect of folds.**
** Location of adenomas missed by optical colonoscopy. Ann Intern Med. 2004;141:352–359
Missed Adenoma Rate
• 395 subjects were randomized to SC followed
by TEC (Third-eye Colonoscopy) or TEC
followed by SC
• 173 subjects underwent SC and then TEC, and
TEC yielded 78 additional polyps (48.8%),
including 49 adenomas (45.8%).
• In 176 subjects undergoing TEC and then SC,
SC yielded 31 additional polyps (19.0%),
including 26 adenomas (22.6%)
Gastrointest Endosc 2011; 73:480–489.
Can Poor ADA Detection be
Improved with Interventions?
• During a period of 3 years, a total of 97,623
colonoscopy examinations were performed in the 5
AECs by 51 gastroenterologists, of which 47,253 were
screening examinations.
• Adenoma detection rates for individual physicians
varied from 10%–39%
• Mean ADR 22%
• During a period of 3 years, 5 specific interventions were
implemented; each was designed to improve adenoma
detection rate
• ADR did not change in response to 5 separate
educational and feedback interventions
Clin Gastro Hepatology 2009:7:1335
Can Poor ADA Detection be
Improved with Interventions?
• Instituting a longer withdrawal time policy or
measuring withdrawal time
• Providing periodic feedback on withdrawal times,
polyp detection rates, and patient satisfaction scores
• Combining longer withdrawal times with monitoring
and feedback
• Implementation of a multifaceted program that
included training, a repeat attempt at cecal intubation,
and education on inspection techniques or
• Education and feedback on withdrawal times combined
with a financial penalty.
Clin Gastro Hepatology 2009:7:1335
Clin Gastro Hepatology 2009:7:1335
Can Poor ADA Detection be Improved
with Interventions? Meta-analysis
• Systematic review of 15 intervention studies (2008-2011)
–
–
–
–
Total withdrawal time alone
Total withdrawal time plus confidential feedback
Segmental withdrawal time plus enhanced inspection techniques
Multiple intervention
• ADR range 12.7%-62%
• Only study one reported a demonstrable improvement in
adenoma detection rate.
– In that study, longer withdrawal time through use of an audible
timer paired with training on enhanced inspection techniques
was associated with a nearly 50% increase in adenoma detection
rates among 12 examiners
Gastrointestinal Endoscopy 2011; 74(3):656
Videorecording of Colonoscopy Associated
with Significant Increase in ADR
October 2012 American College Gastroenterology Presentation
Videorecording of Colonoscopy Associated
with Significant Increase in ADR
•
•
•
•
•
Prospective study of 6 gastroenterologists
208 baseline exams
213 videorecorded exams
Average ADR went from 33.7% to 38.5%
Individual doctors:
– 5/6 showed improvement
– GI with second lowest ADR : 22.6%
57.7%
Madhoun et al. GIE (in press)
Can Technology Improve the
Efficacy of Colonoscopy?
New Technologies to Improve
Adenoma Detection Rate
•
•
•
•
•
•
High-resolution colonoscopy,
Chromo-endoscopy,
Wide-angle colonoscopy
Narrow-band imaging,
Third Eye Retroscope
Cap-assisted Colonoscopy
Most of these techniques are associated with increased
procedure duration, higher cost, and no clear benefit
over high-quality standard colonoscopy
Low-tech to Improve Adenoma
Detection Rate
•
•
•
•
•
Optimize bowel prep quality
Maximize cecal intubation rate
Water insufflation technique
Cecal retroflexion
Obsessive compulsive examination
Reduce Incomplete
Colonoscopies
Incomplete Colonoscopy
• A large community-based study showed that up to 13%
of colonoscopies failed to reach the cecum,
• One common cause: a severely angulated or fixed
sigmoid colon, which is often associated with sigmoid
diverticular disease and/or previous pelvic surgery.
– An angulated sigmoid colon can usually be overcome by the
use of a thin instrument, such as a pediatric colonoscope,
gastroscope, or enteroscope.
• A second major cause of technical difficulty is a
markedly redundant colon.
• Poor bowel prep is also associated with lower cecal
intubation
Water Immersion
• Numerous studies have evaluated the use of
water immersion that warm-water immersion
can speed insertion through the whole or left side
of the colon and reduce pain and discomfort .
• In water immersion, the colon is filled with water
rather than gas during the insertion phase.
• With the patient in the left lateral decubitus
position, the sigmoid colon sinks into the left
lower quadrant and remains shorter and less
distended with fewer angulations compared with
insertion with gas insufflation.
Water Immersion Simplifies Cecal Intubation
in Pts with Redundant Colons and Previous
Incomplete Colonoscopies
• 345 consecutive patients referred to a tertiary
center for the indication of a previous
incomplete colonoscopy
• Cecal intubation was achieved in 332 of 345
patients (96.2%)
• An external straightening device was used in 6
of 178 cases with water immersion (3.4%)
compared with 25 of 168 cases with air
insufflation (15%) (P < .0001).
Gastrointestinal Endoscopy Volume 76, Issue 4 , Pages 812-817, October 2012
Improve Bowel Preparation
Poor Bowel Prep and ADR
• Washington University study of patients who had prior
colonoscopy with inadequate prep
• Inadequate bowel preparation was reported on 373
patients, with an initial adenoma detection rate of 25.7%
• Of 133 patients who underwent repeat colonoscopy, 33.8%
had at least 1 adenoma detected, and 18.0% had high-risk
states detected
– Per-adenoma miss rate was 47.9%.
• The majority of adenomas (64.8%) were missed in the
proximal colon.
• 80% of advanced adenomas (defined as adenomas ≥1 cm or
with villous components or high-grade dysplasia) also were
located in the proximal colon
Gastrointestinal endoscopy 2012;75: 1197
Bowel Prep and ADR
• Retrospective study of 12,872 colonoscopies.
• Preparation quality was suboptimal (poor or fair) in 3047
patients (24%).
• Among these 3047 patients, repeat examination was
performed in <3 years in 505 (17%)
• Among 216 repeat colonoscopies with optimal preparation,
83 adenoma were seen only on the second examination, an
adenoma miss rate of 42% (95% CI, 35-49).
• The advanced adenoma miss rate was 27%
• For colonoscopies repeated in <1 year, the adenoma and
advanced adenoma miss rates were 35% and 36%,
respectively.
Gastrointestinal EndoscopyVolume 73, Issue 6 :1207-1214, June 2011
Conventional PM only Dosing versus
PM/AM Split-dosed Bowel Preparations.
Randomized Study of Split-dosage vs Nonsplit Dosage Regimens of PEG Solutions
Randomized Study of Split-dosage vs Nonsplit Dosage Regimens of PEG Solutions
• Aborted procedures were significantly more frequent in
patients randomized to the non-split-dosage group
(91/430 [21.2%] vs 30/432 [6.9%] of the split-dosage
group, P < .0001).
• Failed intubation to the cecum was recorded in 41 of 354
patients (11.7%) with fair/poor bowel cleansing and in 6
of 513 patients (1.2%) with good/excellent bowel
cleansing (P = .00001).
• Polyp detection rate was significantly higher in patients
with bowel cleansing rated as fair/good (57/209, 27.3%)
or good/excellent (126/512, 24.6%) compared with those
with bowel cleansing rated as poor/fair (18/147, 12.2%)
(P = .001).
Gastrointestinal Endoscopy 2012;72:313
Is Cecal Retroflexion Effective?
• Prospective study of 1000 patients undergoing
colonoscopy ( non-controlled, 2 endoscopists)
• Pproximal colon retroflexion was achievable in
approximately 95% of routine colonoscopies,
• It was safe, and it identified additional polyps
(including additional flat lesions) in 5.8% of
patients.
• Finding additional polyps on retroflexion was
associated with older age, male sex, and the
detection of polyps in the forward view.
Gastrointestinal Endoscopy 2011;Volume 74, Issue 2 : 246-252,
Quality Measures for
Colonoscopy
• Cecal intubation rate goal = >95%
– Photocumentation of appendix/ICV
• ADR : bare minimum acceptable
– Males 25% Females 15%
– Reasonable ADR: Males 30-35% Females 20-25%
• Technique Pretend the exam is being videotaped
–
–
–
–
Cecal retroflexion
Water immersion for difficult sigmoid
Minimal withdrawal time = as long as it takes
Perform your own tandem examination
Optimization of Colonoscopic
Examination
• Optimize bowel prep
– Split dose if possible
– Colonoscopy within 6-8 hours of last dose
• Compliance with recommeded postpolypectomy surveillance guidelines
• Tract adverse events
– Perforation: <1/4000 diagnostic
<1/2000 therapeutic
– Post polypectomy bleeding
Third Eye Retroscope
Catheter Cost: $375/case
Processor $20,000
Cap Assisted Colonoscopy
Cap-Assisted Colonoscopy
• Attaching a small transparent cap to the tip of the
colonoscope can help depress haustral folds, thereby
decreasing the blind mucosal surface area and may
improve adenoma detection rates.
• In some studies, this approach has been reported to be
associated with improved polyp detection, reduced
cecal intubation time, and enhanced cecal intubation
rate
• Meta-analysis of 16 randomized controlled clinical
trials were included consisting of 8,991 subjects (CAC:
4,501; SC: 4,490)
• CAC demonstrated marginal benefit over SC for polyp
detection and shortened the cecal intubation time.
Am J Gastroenterol. 2012;107(8):1165-1173
Fecal Immunochemical Test
(FIT)
Mean fecal Hgb ng/ml
Quantative Fecal Hgb and
Lesions Found on Colonoscopy
Ann. Int. Medicine 2007;146:244
Colonoscopy vs FIT
• Randomized, controlled trial involving
asymptomatic adults 50 to 69 years of age,
compared one-time colonoscopy in 26,703 subjects
with FIT every 2 years in 26,599 subjects.
• The primary outcome was the rate of death from
colorectal cancer at 10 years
• Hypothesized that FIT screening every 2 years
would be non-inferior to one-time colonoscopy
with respect to a reduction in mortality related to
colorectal cancer among average-risk subjects.
• 2011-2021: first-year results
N Engl J Med 2012;366:697-706
Enrollment and Outcomes.
Quintero E et al. N Engl J Med 2012;366:697-706
Diagnostic Yield of Colonoscopy and Fecal
Immunochemical Testing (FIT), According to the
Intention-to-Screen Analysis.
Quintero E et al. N Engl J Med 2012;366:697-706
Diagnostic Yield of Colonoscopy and FIT,
According to the Intention-to-Screen Analysis
and the Location of the Colorectal Lesion.
Quintero E et al. N Engl J Med 2012;366:697-706
Detection Rate for Colonoscopy and FIT,
According to the As-Screened Analysis.
Quintero E et al. N Engl J Med 2012;366:697-706
Enrollment and Outcomes.
21.1%
35.1%
17.25%
32.5%
Hgb 75 mg/ml >
5.2%
0.52%
42.2%
5.45%
9.73%
37.5%
Quintero E et al. N Engl J Med 2012;366:697-706
Accuracy of One-Time FIT in Patients
Referred for Surveillance Colonoscopy
• Cohort study of 1041 asymptomatic high-risk pts
(personal hx of adenomas/CRC or family hx of CRC),
who provided 1-2 FITs before elective colonoscopy.
• Five CRCs (0.5%) and 101 advanced adenomas (9.7%)
were detected by colonoscopy
• Single FIT sampling resulted in a sensitivity, specificity,
PPV and NPV for CRC of 80%, 89%, 3% and 99.9%,
respectively, and for advanced adenoma of 28%, 91%,
24% and 92%, respectively
• In once-only FIT sampling before surveillance
colonoscopy, 70% of advanced neoplasia were missed.
BMC Gastroenterol. 2012;12(94)
FIT Testing Is Equally Sensitive for
Proximal and Distal Advanced Neoplasia
• Data from 1,256 colonoscopies to est. the sensitivity,
specificity, and PPV and NPV of FIT and to evaluate its
sensitivity in detecting right-sided (proximal) and leftsided (distal) advanced neoplasia.
• FIT results were positive in 121 (10%) participants at a
cutoff level of 50 ng/mL, in 88 (7%) at 75 ng/mL, and in
71 (6%) at 100 ng/mL.
• Nine out of ten screening participants with CRC and
four out of ten with advanced neoplasia will be detected
using one single FIT at low cutoff.
• Sensitivity in detecting proximal and distal advanced
neoplasia is comparable.
Am J Gastroenterol 2012; 107:1570–1578