colorectal cancer update 2008 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Colorectal Cancer: Update 2008 PowerPoint Presentation
Download Presentation
Colorectal Cancer: Update 2008

Loading in 2 Seconds...

play fullscreen
1 / 36

Colorectal Cancer: Update 2008 - PowerPoint PPT Presentation


  • 303 Views
  • Uploaded on

Colorectal Cancer: Update 2008 Durado Brooks, MD, MPH Director, Prostate and Colorectal Cancer Colorectal Cancer The third most common cancer in U.S. 148,810 new cases expected in 2008 The second deadliest cancer 49,960 deaths nationwide

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Colorectal Cancer: Update 2008' - Thomas


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
colorectal cancer update 2008
Colorectal Cancer:Update 2008

Durado Brooks, MD, MPH

Director, Prostate and Colorectal Cancer

colorectal cancer
Colorectal Cancer
  • The third most common cancer in U.S.
  • 148,810 new cases expected in 2008
  • The second deadliest cancer
  • 49,960 deaths nationwide
  • More than 1 million Americans living with colorectal cancer
colorectal cancer3

CENTERS FOR DISEASE CONTROL

AND PREVENTION

Colorectal Cancer

Sporadic (average risk) (65%–85%)

Family

history(10%–30%)

Rare syndromes (<0.1%)

Hereditary nonpolyposis colorectal cancer (HNPCC) (5%)

Familial adenomatous polyposis (FAP) (1%)

risk factor polyps
Risk Factor - Polyps

Different types

  • Hyperplastic
    • minimal cancer potential
  • Adenomatous
    • approximately 90% of colon and rectal cancers arise from adenomas
benefits of screening
Benefits of Screening
  • Cancer Prevention
    • Removal of pre-cancerous polyps prevent cancer (unique aspect of colon cancer screening)
  • Improved survival
    • Early detection markedly improves chances of long term survival
colorectal screening rates
Colorectal Screening Rates
  • Just 40% of colorectal cancers are detected at the earliest stage.
  • A little more than half* of Americans over age 50 report having had a recent colorectal cancer screening test
  • Slow but steady improvement in these numbers over the past decade (but all are not benefiting to the same degree)

*varies based on data source

slide9
Trends in Recent* Endoscopy Prevalence (%), by Educational Attainment and Health Insurance Status, Adults 50 Years and Older, US, 1997-2004

*A flexible sigmoidoscopy or colonoscopy within the past five years. Note: Data from participating states and the District of Columbia were aggregated to represent the United States.

Source: Behavioral Risk Factor Surveillance System CD-ROM (1996-1997, 1999) and Public Use Data Tape (2001, 2002, 2004), National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention and Prevention, 1999, 2000, 2002, 2003, 2005.

slide10

Trends in Recent* Fecal Occult Blood Test Prevalence (%), by Educational Attainment and Health Insurance Status, Adults 50 Years and Older, US, 1997-2004

*A fecal occult blood test within the past year. Note: Data from participating states and the District of Columbia were aggregated to represent the United States.

Source: Behavioral Risk Factor Surveillance System CD-ROM (1996-1997, 1999) and Public Use Data Tape (2001, 2002, 2004), National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention and Prevention, 1999, 2000, 2002, 2003, 2005.

colorectal screening rates low reasons according to patients
Colorectal Screening Rates Low:Reasons (according to Patients)
  • Low awareness of CRC as a personal health threat
  • Lack of knowledge of screening benefits
  • Fear, embarrassment, discomfort
  • Time
  • Cost
  • Access
  • “My doctor never talked to me about it!”
acs 2003 crc prevention and early detection recommendations
ACS 2003 CRC Prevention and Early Detection Recommendations
  • Fecal Occult Blood Testing (FOBT)

*Guaiac *Immunochemical

  • Flexible Sigmoidoscopy (FSIG)
  • FSIG + FOBT
  • Colonoscopy
  • Double Contrast Barium Enema (DCBE)
the 2008 crc guidelines update was a joint effort of 5 organizations
The 2008 CRC Guidelines Update was a Joint Effort of 5 Organizations
  • American Cancer Society
  • U. S. Multi-Society Task Force on Colorectal Cancer
    • American Gastroenterological Association
    • American College of Gastroenterology
    • American Society of Gastrointestinal Endoscopists
  • American College of Radiology
crc screening guidelines what s new
CRC Screening Guidelines: What’s New?

CRC screening tests are grouped into two categories:

  • Tests that detect cancer and precancerous polyps*
  • Tests that primarily detect cancer
  • It is the strong opinion of the ACS CRC Advisory Group that colon cancer prevention should be the primary goal of CRC screening.
    • Exams that are designed to detect both early cancer and precancerous polyps should be encouraged if resources are available and patients are willing to undergo an invasive test
    • If the full range of screening tests are not available, physicians should make every effort to offer at least one test from each category
crc screening guidelines what else is new
CRC Screening Guidelines: What Else is New?
  • Two new tests recommended:
    • stool DNA (sDNA) and
    • computerized tomographic colonography (CTC) – sometimes referred to as virtual colonoscopy
  • The guidelines:
    • establish a sensitivity threshold for recommended tests
    • delineate important quality-related factors for each form of testing
    • continue to emphasize options for testing
  • An overriding goal of this update is to provide a practical guideline for physicians and the public

The full article can be accessed at:

http://caonline.amcancersoc.org/cgi/content/full/CA.2007.0018v1

2008 crc screening guidelines
2008 CRC Screening Guidelines

Average risk adults age 50 and older

  • Tests that detect adenomatous polyps and cancer
    • Flexible sigmoidoscopy (FSIG) every 5 years*, or
    • Colonoscopy every 10 years, or
    • Double contrast barium enema (DCBE) every 5 years*, or
    • CT colonography (CTC) every 5 years*
  • Tests that primarily detect cancer
    • Annual guaiac-based fecal occult blood test (gFOBT)* with high test sensitivity for cancer, or
    • Annual fecal immunochemical test (FIT)* with high test sensitivity for cancer, or
    • Stool DNA test (sDNA)*, with high sensitivity for cancer, interval uncertain

*Note: All positive screening tests should be followed up with colonoscopy

stool dna test sdna
Stool DNA Test (sDNA)

Rationale

  • Fecal occult blood tests detect blood in the stool – which is intermittent and non-specific
  • Colon cells are shed continuously
  • Polyps and cancer cells contain abnormal DNA
  • Stool DNA tests detect abnormal DNA from cells that are passed in the stool*

*All positive tests should be followed with colonoscopy

genetic model of colorectal cancer

Early Cancer

Late Cancer

Adenoma

Late Adenoma

Normal

Epithelium

Optimum phase for early detection

Genetic Model of Colorectal Cancer

Bat-26 (Sporadic)

p53

APC

Mutation

Bat-26

(HNPCC)

K-ras

Dwell Time: Many decades2-5 years 2-5 years

Courtesy of Barry M. Berger. MD, FCAP

EXACT Sciences

sdna sample collection22
sDNA - Sample Collection

Patient seals container and ships back to designated lab (all packing materials and labels supplied)

Collection bucket inserted into bracket and installed under toilet seat

Patient supplies whole stool sample; no diet or medication restrictions

Patient seals sample in outer container and freezer pack

sdna evidence
sDNA: Evidence

Three versions of the Exact Sciences test have been evaluated

  • Version 1 (K-ras, APC, p53,BAT-26, DIA) was evaluated in the Imperiale trial
  • Version 1.1 (K-ras, APC, P53), PreGen-Plus is the currently marketed test
  • Version 2 (Vimentin only, or Vimentin + DIA) is currently under evaluation
  • Earlier and more recent versions were evaluated in smaller, mixed populations
stool dna potential advantages
Stool DNA: Potential Advantages
  • No dietary restrictions needed
  • Specificity for cancer may be significantly higher than other forms of stool testing
  • No stool sampling required (entire bowel movement collected)
  • Company-sponsored studies report high levels of patient acceptance
stool dna limitations
Stool DNA: Limitations
  • Misses some cancers
  • Sensitivity for adenomas with current commercial version of test is low
  • Technology (and test versions) are in transition
  • Appropriate re-screening interval is not known
  • Costs much more than other forms of stool testing (approximately $300 - $400 per test)
  • Not covered by most insurers
  • Not clear how to manage positive stool DNA test if colonoscopy is negative
  • FDA approval concerns
ct colonography ctc
CT Colonography (CTC)

CTC Image

Optical Colonoscopy

Courtesy of Beth McFarland, MD

ct colonography
CT Colonography

2-D view

3-D view

Polyp

Courtesy of Beth McFarland, MD

ct colonography rationale
CT Colonography: Rationale
  • Allows detailed evaluation of the entire colon
  • Minimally invasive (rectal tube for air insufflation)
  • No sedation required
  • A number of studies have demonstrated a high level of sensitivity for cancer and large polyps
ctc vs optical colonoscopy sensitivities for all polyps
CTC vs. Optical Colonoscopy: Sensitivities for All Polyps

Polyp Size

>10mm >8mm >6mm

CTC 92.2% 92.6% 85.7%

Colonoscopy 88.2% 89.5% 90.0%

Pickhardt et al, NEJM 2003

ctc additional findings
CTC: Additional Findings
  • CTC identified 55 polyps not seen on initial colonoscopy
    • 21 adenomas
    • One 11 mm malignant polyp
  • Extra-colonic findings
    • 5 asymptomatic cancers
    • Aortic aneurysms
    • Renal and gall bladder calculi

Pickhardt et al, NEJM 2003

ctc follow up colonoscopy
CTC: Follow-up colonoscopy
  • Indication for diagnostic/therapeutic colonoscopy varies markedly based on selected polyp size threshold
  • Important implications for cost-effectiveness of CTC

Pickhardt et al, NEJM 2003

ct colonography additional evidence
CT Colonography: Additional Evidence
  • A number of other studies have demonstrated a high level of sensitivity for cancer and large polyps
  • Findings from the recently completed multi-center ACRIN trial reportedly are similar to those of Pickhardt et al
    • Some results from this trial have been reported at medical meetings, but have not yet been published
    • Manuscript has been prepared and is currently under review
ct colonography limitations
CT Colonography: Limitations
  • Requires full bowel prep (which most patients find to be the most unpleasant aspect of colonoscopy)
  • Colonoscopy is required if abnormalities detected, sometimes necessitating a second bowel prep
  • Extra-colonic findings can lead to additional testing (may have both positive and negative implications)
  • Controversy regarding management of small polyps, sensitivity for “flat polyps”
  • Radiation exposure
  • Steep learning curve for radiologists
  • Limited availability to high quality exams in many parts of the country
  • Most insurers do not currently cover CTC as a screening modality
2008 crc guidelines continue to emphasize options because
2008 CRC Guidelines continue to emphasize options because:
  • Evidence does not yet support any single test as “best”
    • Uncertainty exists about performance of different screening methods with regard to benefits, harms, and costs (especially on programmatic basis)
  • Uptake of screening remains disappointingly low
  • Individuals differ in their preferences for one test or another
  • Primary care physicians differ in their ability to offer, explain, or refer patients to all options equally
  • Access is uneven geographically, and in terms of test charges and insurance coverage
if tests that can prevent crc are preferred why not recommend them alone
If tests that can prevent CRC are preferred, why not recommend them alone?
  • Greater patient requirements for successful completion
    • Endoscopic and radiologic exams require a bowel prep and an office or facility visit
  • Higher potential for patient injury than fecal testing
    • Risk levels vary between tests, facilities, practitioners
  • Patient preference
    • Many individuals don’t want an invasive test or a test that requires a bowel prep
    • Some prefer to have screening in the privacy of their home
    • Some may not have access to the invasive tests due to lack of coverage or local resources