Download Screening for coloretal cancer

POPULATION SCREENING FOR COLORECTAL
CANCER
- UPDATE OF EVIDENCES
Dr Jennifer Lee
PYNEH
SCREENING – THE PRINCIPLES
World Health Organization Criteria
Important common health problem
Natural history of disease adequately understood and
there is asymptomatic early disease stage
Treatment available
Diagnostic tool available
Cost-effective and competent follow-up programs
available
IMPORTANT COMMON HEALTH PROBLEM ?
3rd commonest cancer in US
 3rd leading cause of cancer death in both men
and women in the US
 Incidence:

 Male:
57.2/100, 000 population
 Female: 42.5/100,000 population
American Cancer Society
COLORECTAL CANCER IN HONG KONG

Incidence:
 Male:
47.1/100, 000
population
 Female:
31.0/100,000
population
(Hong Kong Cancer Registry )
PROGNOSIS
5 year survival:
 90%
if disease diagnosed while still localized
 68% for regional disease
 10% if distant metastasis present
NATURAL HISTORY OF DISEASE : PATHOGENESIS
Journal of InternalMedicine 270; 87–98
SCREENING MODALITIES
Screening Modalities
Stool based
•Faecal Occult Blood Test
•Faecal Immunochemical Test
•Stool DNA
Structural Exam
•Flexible sigmoidoscopy
•Colonoscopy
•Double contrast Barium
Enema
•CT colonography
•Colon capsule endoscopy
Sensitivity
Evidence
Recommendation
Faecal Occult
Blood
37.1% – 79.4%
RCT proven
Mortality ↓15-33%
Incidence ↓20%
Annually
screening
Faecal
Immunochemical
test
81% - 94%
Stool DNA
52%-91%
?
Barium Enema
Cancer: 85-97%
Adenoma>1cm:
~48%
5 years*
Barium enema: not recommended by Asia Pacific Working Group
FLEXIBLE SIGMOIDOSCOPY





Evaluates rectum, sigmoid colon, descending colon
Does not require sedation /full bowel preparation
Shorter procedural time
Can be done by trained nurse/physician assistants
Cost: ~ USD 244
COLONOSCOPY

Gold standard for diagnosis
Requires bowel preparation and sedation
Potential risk of perforation and post-polypectomy
bleeding
Cost: ~USD 450

Efficacy:





No prospective, RCT of screening colonoscopy for incidence/
mortality reduction
Indirect evidence of incidence reduction in RCT of other
screening test

170,432 individuals aged 55-64 randomized






No family history / colonic workup within 3 years / no bowel symptoms
Intervention group ( 57,237 ) vs controlled group (NO screening)
(113,195)
71% (40,674) had flexible sigmoidoscopy done
5% referred for full colonoscopy due to high risk neoplasms
Participants flagged in national health registry for causes of
death and colorectal cancer diagnoses
Follow up period: 11 years
Lancet 2010; 375: 1624-33


Colorectal cancer detection rate: 3.5 / 1000 screened
All distal neoplasia (adenoma/cancer) 12% of screening group

In intention-to-treat analyses, colorectal cancer incidence in the
intervention group was reduced by 23% and mortality by 31%

23% of patients who had colonoscopy has proximal polyps



5% advanced proximal adenomas
0.4% proximal cancers
No significant effect on incidence of proximal colon cancers
Is this UK study applicable to Hong Kong?
DIFFERENCE BETWEEN EAST & WEST?
Figures comparing 3 Caucasian populations studies VS 5 studies from Asian
populations and Australia
Polyps
Advanced
Neoplasia
Asia
West
Proximal
30%
49%
Distal
57%
49%
Synchrounous
13%
2%
Proximal
29%
35%
Distal
52%
59%
Synchronous
19%
6%
Sung et al, Gut 2008;57:1166–1176
5464 colonoscopy performed; Mean age: 55.0 +/-15.5 year
 Advanced neoplasm found in 512 patients (9.4%)
 Carcinoma found in 322 patients (5.9%)

majority of colonic neoplasms are in distal colon
 advanced neoplasm (65.1%) ; Cancer (71.1%)
 Similar to western figures
•
Volume 64, No. 5 : 2006 GASTROINTESTINAL ENDOSCOPY
WHAT ARE WE MISSING?
 2.2%
of patients with advanced proximal
neoplasm (including 1% cancer) will be
missed by flexible sigmoidoscopy alone

61% of patients with advanced proximal lesions had no colonic
neoplasm in the distal colon
TAIWAN
•asymptomatic Chinese
•1708 total colonoscopy performed
•263 (15.4%) had colorectal neoplasia;
•51 (3.0%) had advanced lesions
• 125 (37.8%) were proximal in location
•Two thirds (66.7%) of patients with proximal advanced
lesions had no distal lesion
• 1.8% of subjects without distal neoplasm had
proximal advanced neoplasm
• proportion of patients with proximal or proximal plus
distal lesions increased with age
(Volume 61, No. 4 : 2005 GASTROINTESTINAL ENDOSCOPY)

Perforations:
1/40 332 flexible sigmoidoscopy
 4/2377 colonoscopy
 All after snare polypectomy
 3 required surgery


Bleeding post- sigmoidoscopy:


12 (8 after polypectomy); 1 required surgical treatment
Bleeding post colonoscopy:

9 (all after polypectomy)
POST-POLYPECTOMY BLEEDING
LOCAL DATA
 Single center
 5593 colonoscopy case reviewed
 Polypecotomy done in 1657 cases

Risk of post-polypectomy bleeding ~
2.2%
Hui AJ et. Al
Gastrointest Endo 2004, 59(1):44-48
WHAT TO CHOOSE?
Flexible Sigmoidoscopy
Shorter procedural time
No full bowel preparation
No sedation
Lower cost
Lower complication rate
More acceptable
•May miss proximal lesions
Colonoscopy
Evaluates whole colon
•Longer procedural time
•Full bowel preparation
•Cost
•Potential complication related
to sedation , polypectomy
CURRENT RECOMMENDATION IN HONG KONG
2010 Recommendation on CRC screening by
Cancer Expert Working Group
 Screening to be considered in individuals aged
50 to 75 with average risk

 Annual/
biennial FOBT
 FS every 5 years
 Colonoscopy every 10 years
CT COLONOGRAPHY (VIRTUAL COLONOSCOPY)

2D&3D images obtained by CT
Rapid advancement due to newer multi-detector CT
Non-invasive
Cost : ~ USD 800

Efficacy:







No RCT to demonstrate incidence / mortality reduction
Sensitivity for large polyps >1cm: ~ 85-93%
Small polyps (6-9mm): ~70-86%
Sensitivity for invasive cancer: 96%
Eur Radiol (2012) 22:1495–1503
Margriet C. de Haan et al.
CT COLONOGRAPHY




higher diagnostic yield per 100 invitees than primary gFOBT and FIT
screening
similar yield as sigmoidoscopy and colonoscopy screening
Not therapeutic
per-patient false-positive rates:






polyps >6mm : 3.6%
polyps >10-mm : 2.1%
Cost-effectiveness unknown
?Impact of detecting extracolonic disease
Colonoscopy to be offered if largest polyp detected >6mm
Recommended for individuals who decline colonoscopy/not good
candidate for colonoscopy
Margriet C. de Haan et al. Eur Radiol (2012) 22:1495–1503
David H. Kim , et al. Radiology(2012),254, 493-500
COLON CAPSULE ENDOSCOPY




No need for sedation / air
insufflation / radiation exposure
NOT therapeutic
Cost: ~USD 950
Results affected by



Bowel preparation
Colonic transit time
Battery life
COLON CAPSULE ENDOSCOPY
Gossum, et al
Rokkas, et al
Meta-analysis
626 CCE
•
•
•
•
Sensitivity
Specificity
Polyps >6mm
64%
84%
Advanced
adenoma
73%
79%
Significant polyps
(size >6mm /
no.>3)
69%
86%
All polyps
73%
89%
Sensitivity for cancer : 74%
Polyp and cancer pick up rate: inferior than colonoscopy
False positive rate: 33%
Future improvement ?
Gossum, et al, N Engl J Med 2009;361:264-70
Rokkas, et al, Gastrointest Endosc 2010;71:792-8
SUMMARY
Colorectal cancer screening is important
 Recent large scale population randomised
study in UK suggest flexible sigmoidoscopy is
effective for screening
 However ~2% proximal lesions may be missed
 Newer modalities such as CT colonography and
colon capsule endoscopy is a viable alternative,
but needs further evaluation for effectiveness
as screening tool

THANK YOU
COST-EFFECTIVENESS OF SCREENING
•Hypothetical population of 100, 000 population for screening
•annual FOB / 5 yearly FS / 10 yearly Colonoscopy
•Screening at age 50 until 80
•Cost of treatment including chemotherapy calculated
•incremental cost-effectiveness ratio (Cost per life year saved)
Aliment Pharmacol Ther 28, 353–363
FLEXIBLE SIGMOIDOSCOPY
UK trial: longeset period FU, 11 years
 Norwegian Colorectal Cancer Prevention
(NORCCAP) trial , inter-rim report 6 years

Reduce mortality only, no observaed reduced incidence
so far (since early peak of screening detected cancer)
 Populations study

Prostate, Lung, Colorectal and Ovarian (PLCO)
cancer screening trial in the USA
 Italian Screening COlon REtto (SCORE): follow UK
protocol

COLONOSCOPY


Primary screening colonoscopy: Poland, Germany
Randomized trials for screening colonoscopy:

Spanish trial, 55 000 individuals between 50 and 69 years
of age are being randomly assigned to either iFOBT or
colonoscopy


final results are expected in 2021 after 10 years of follow-up
Nordic–European Initiative on Colorectal Cancer (NordICC) is
a multicentre, multinational randomisied trial
66 000 individuals are randomly assigned to either colonoscopy or
no screening
 Planned 15-year follow-up
 an interim analysis after 10 years due around 2022

REFERAL FOR COLONOSCOPY

High-risk criteria:
1
cm or larger
 three or more adenoma
 tubulovillous or villous histology
 severe dysplasia or malignant disease
 20 or more hyperplastic polyps above the distal
rectum