Is Colonoscopy Justified for Any Polyp Discovered During
This presentation is the property of its rightful owner.
Sponsored Links
1 / 49

Is Colonoscopy Justified for Any Polyp Discovered During Computed Tomographic Colonography (CTC)? PowerPoint PPT Presentation


  • 71 Views
  • Uploaded on
  • Presentation posted in: General

Is Colonoscopy Justified for Any Polyp Discovered During Computed Tomographic Colonography (CTC)?. Am J Gastroenterol 2005;100:1903 – 1908. David F. Ransohoff, M.D. Douglas K. Rex, M.D. Edgar Achkar, M.D. Am J Gastroenterol 2005;100:1903 – 1908. Douglas K. Rex, M.D.

Download Presentation

Is Colonoscopy Justified for Any Polyp Discovered During Computed Tomographic Colonography (CTC)?

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


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Is Colonoscopy Justified for Any Polyp Discovered DuringComputed Tomographic Colonography (CTC)?

Am J Gastroenterol 2005;100:1903–1908


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

David F. Ransohoff, M.D.

Douglas K. Rex, M.D.

Edgar Achkar, M.D.

Am J Gastroenterol 2005;100:1903–1908


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Douglas K. Rex, M.D.

Am J Gastroenterol 2005;100:1903–1908


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

WHY SHOULD ALL POLYPS BE REMOVED?

  • It is radical to suggest that none with polyps smaller than 1 cm detected by a CRC screening test need to be offered colonoscopic polypectomy.

  • There is a consensus that patients with polyps smaller than 1 cm detected by barium enema should be referred for polypectomy and it is common practice to remove such polyps.

  • Most patients with adenomas of any size detected by flexible sigmoidoscopy are still referred for colonoscopy

  • Since 95% of all colon polyps are smaller than 1 cm in size and since all polyps seen during colonoscopy are removed, it is a major paradigm shift to institute a policy of leaving most colorectal neoplasms in place.

These arguments are irrelevant, may be we are all the way wrong !!!


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

COST-EFFECTIVENESS OF CTC?

  • At a cutoff size of 1 cm, about 10% of the screened population will be referred for polypectomy, whereas at 6 mm, 30% or more will be referred.

  • For an expensive diagnosis test (CTC), the “cutoff” may well determine the cost-effectiveness of the test.

  • It is problematic to permit any discussion regarding the optimal cutoff size for CTC to be driven primarily by notions of which size will make CTC cost-effective.

  • Small polyps that are not referred for colonoscopy is the recommendation that CTC be repeated to monitor the polyp within 1–3 yr which is not cost effective.

Why is it problematic to determine a cutoff size based on cost effectiveness analysis?


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

ARE ALL SMALL POLYPS EQUAL?

  • The natural history of small polyps, and such an understanding does not exist.

  • CTC provides information on polyp size, number, and shape but not on polyp histology.

Not totally precise, in any case we need to base our decisions on the our best knowledge and evidence.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

ARE ALL SMALL POLYPS EQUAL?

  • Polyps smaller than 5 mm have a very low risk of invasive cancer or high-grade dysplasia, and villous elements are uncommon

  • For polyps measuring 6–9 mm the risk of invasive cancer has been estimated to be as high as 0.9%, the risk of high-grade dysplasia about 4%, and 10% or more will have villous elements.

  • Some will consider those numbers to be low, but many patients and primary care physicians will consider them sufficiently high that they prefer to have such lesions removed.

Key Question


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

A REASONABLE COMPROMISE

  • It seems reasonable to suggest that colonoscopy and polypectomy should be offered at least to healthy patients with polyps 6 mm or larger or who have three or more polyps of any size.

  • This is not to say that some patients with one or two polyps smaller than 5 mm should not undergo colonoscopy.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

SUMMARIZING WHY SHOULD POLYPS BE REMOVED

  • Many patients will be lost to follow-up.

  • Following small polyps by repeated CTC will subject patients to radiation and involve high costs.

  • There is insufficient information on the natural history of small polyps. A reasonable compromise would be to offer colonoscopy to healthy patients who have polyps 6 mm or larger or who have three or more polyps of any size on CTC.

  • Patients with only one or two polyps smaller than 5 mm could be referred for colonoscopy or considered normal.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

David F. Ransohoff, M.D.

Am J Gastroenterol 2005;100:1903–1908


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Polyp Size and Cancer Risk

  • The rate that lesions 1 cm or larger grow to become clinical cancer is roughly 1% per year.

  • Polyps, under 6 mm, are common, being present in 30–50% of population, in the United States, above age 50 yr.

  • About 1% of polyps in the 6–9 mm range contain “invasive cancer” and 4% would contain high-grade dysplasia.

  • What is its natural history to become untreatable cancer and over what period of time?”


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Cancer Risk – Other Fields

  • In breast cancer screening, questions have been raised about whether the clinical significance and natural history of ductal carcinoma in situ (DCIS) is ominous enough to warrant the aggressive treatment.

  • Lesions labeled prostate cancer, particularly with low Gleason grades, may have a benign natural history; yet prostate cancer is often treated aggressively.

  • At the biological level, some lesions labeled cancer may not behave like cancer at all; Folkman has termed such lesions “cancer without disease”


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Other Factors Affecting Decision Making

  • Technical improvements in CTC could make a strategy of “watchful waiting” attractive; in particular, development of a laxative-free prep could make CTC popular both in screening and in follow-up.

  • One motivation to be aggressive is that consequences of “missed” cancer can include an unhappy patient, an unhappy doctor, and a potential legal liability.

  • We must accept that some cancers will be missed. As a profession, we must consider what that point is and when forces to be aggressive and to “not miss anything” may become extreme, perhaps leading to suboptimal decision-making


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Decision Making about Prostate Cancer Screening.

  • The benefit of prostate cancer screening is at best uncertain (no RCT), while harms from screening and treatment, such as impotence and incontinence, are common.

  • In a situation with uncertain benefit and well-known and frequent harms, one might expect patients and doctors to be cautious about screening and treatment. Yet prostate cancer screening is commonly done, and patients and physicians receive almost no “negative feedback” following a decision to be aggressive.

  • Even when a decision for aggressive treatment leaves patients impotent and incontinent, 90% are pleased with the decision and would do it again.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

The Future

  • A strong case can be made to use 1 cm as the threshold for work up of lesions found at CTC.

  • In the long run, the decision about which threshold to use now is less important than continuing the technical development of CTC to improve its accuracy, availability, cost, and convenience (e.g., no laxative prep), as well as to learn about natural history of various lesions, so that CTC technology may be maximally applied to benefit patients.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Edgar Achkar, M.D.

Am J Gastroenterol 2005;100:1903–1908


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

CON

  • Dr. Ransohoff argues that watchful waiting is reasonable for lesions between 6 and 9 mm since the cancer potential is small. He uses the analogy of lung, breast, or prostate lesions as examples of watchful waiting.

  • The option of watchful waiting for prostatic ancer is perceived by many physicians and patients as a source of confusion and anxiety rather than true choice.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

PRO

  • Dr. Rex points out that small lesions may indeed harbor cancer and considers watchful waiting as a missed opportunity to diagnose synchronous lesions.

  • Because diminutive lesions have a low risk of cancer he proposes a compromise, agreeing to leave polyps 5 mm or smaller unchecked.

  • To put this debate in perspective, we are arguing over a 4 mm difference for removal of polyps (between 6 and 10 mm).


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

BALANCE

  • I doubt that any logic can ever resolve such differences.

  • The solution to our dilemma is not about agreeing on an exact polyp size to dictate management. It is about resources and compliance.

  • My prediction is that we will continue to argue about polyp size for some time until we agree, hopefully based on solid data, on some middle ground recommendation.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

דיון

מה מהות אי ההתאמה בין ה"בעד" וה"נגד" של כריתת הפוליפ?

האם יש אי הסכמה על הנתונים?


Ellsberg paradox

Ellsberg Paradox

בכד יש 30 כדורים בצבע אדוםו- 60 כדורים חלקם בצבעירוק וחלקם בצבע כחול

בוחרים באופן אקראי כדור

30 אדומים

60 ירוקיםוכחולים

בעיית החלטה I:

  • צריך לבחור בין שתי החלופות הבאות:

  • אם נקבל כדור אדום נקבל 100$, כדור בצבע אחר נקבל 0$

  • אם נקבל כדור כחול נקבל 100$, כדור בצבע אחר נקבל 0$


Ellsberg paradox1

Ellsberg Paradox

בכד יש 30 כדורים בצבע אדוםו- 60 כדורים חלקם בצבעירוק וחלקם בצבע כחול

בוחרים באופן אקראי כדור

30 אדומים

60 ירוקיםוכחולים

בעיית החלטה II:

  • צריך לבחור בין שתי החלופות הבאות:

  • אם נקבל כדור אדום או ירוק נקבל 100$, אם נקבל כדור כחול נקבל 0$

  • אם נקבל כדור ירוק או כחול נקבל 100$, אם נקבל כדור בצבע אדום נקבל 0$


Ellsberg paradox2

Ellsberg Paradox


Ellsberg paradox3

Ellsberg Paradox

בבעיית ההחלטה I רוב האנשים בוחרים א' ואילו בבעיית ההחלטה II רוב האנשים בוחרים ב'.

  • מקבל החלטות שמעדיף חלופה א' סבור שמספר הכדורים הכחולים קטן מ- 30 (אחרת היה בוחר חלופה ב')

  • מקבל החלטות שמעדיף חלופה ב' סבור שמספר הכדורים הירוקיםקטן מ-30 ולכן מספר הכדורים הכחולים גדול מ-30 (אחרת היה בוחר חלופה א')

סתירה


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

דיון

  • רמת סיכון (הסתברות) נוכחי

  • רמת סיכון (הסתברות) עתידי

  • קבלת החלטות מנקודת מבט אישית

  • קבלת החלטות מנקודת מבט ציבורית (מדיניות)


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

  • In a prospectively collected 1988 lesions from 854 subjects (473 male/381 female). Lesion size, location, patient age, sex and the colonoscopist’s clinical impression was recorded.

Ian Craig Lawrance, Colin Sherrington and Kevin Murray

Journal of Gastroenterology and Hepatology 21: (2006) 563–568


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

  • Data were reviewed retrospectively from 3291 colonoscopies performed on asymptomatic patients found to have an adenoma on screening with flexible sigmoidoscopy a few weeks before the colonoscopy or who had a family history of colorectal cancer.

Lynn F. Butterly et al. CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2006;4:343–348


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

Lynn F. Butterly et al. CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2006;4:343–348


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

Lynn F. Butterly et al. CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2006;4:343–348


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

Lynn F. Butterly et al. CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2006;4:343–348


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

  • 3121 (age range, 50 to 75 years) patients at 13 Veterans Affairs medical centers had colonoscopy to determine the prevalence and location of advanced colonic neoplasms with or without distal neoplasia.

N. Engl. J Med 2000;343:162-8


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

  • All pathology reports from colon and rectal polyps from 1999 to 2002 were reviewed. Reports of bowel resections, cancer-free polyps, and polyp-free mucosal biopsies were excluded. A total of 4,443 polyps were found, of which 3,225 were adenomatous

Odom SR et al. American Surgeon. 71(12):1024-6, 2005


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

  • primary screening colonoscopy in 2210 consecutive adults at least 40 yr old, without known risk factors for CRC.

Maite Bete´s, et al. ,Am J Gastroenterol 2003;98:26482654.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Current Risk

  • A retrospective prevalence study of 917 aged 50–75 yr with no cancer-related symptoms,personal or family history of CR neoplasia, who underwent a colonoscopy.

Hana Strul et al. ,Am J Gastroenterol 2006;101:255–262


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Meta Analysis

  • We conducted a meta-analysis to estimate the risk of cancer and dysplasia of polyp size 6-9 mm:

  • The pooled risks for high grade dysplasia and cancer are 4.1% and 1.1% respectively


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

דיון

  • רמת סיכון (הסתברות) נוכחי

  • רמת סיכון (הסתברות) עתידי

  • קבלת החלטות מנקודת מבט אישית

  • קבלת החלטות מנקודת מבט ציבורית (מדיניות)


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

רמת סיכון בעתיד

  • בהנחה שידוע שגודל הפוליפ בין 6-9 מ"מ. מה ההסתברות שנמצא סרטן לאחר שנה, לאחר שנתיים ולאחר שלוש שנים.

  • קצב המעבר של פוליפ בגודל של 10 מ"מ או יותר לסרטן הוא כ- 1% בשנה.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

רמת סיכון בעתיד

  • ההסתברות של פוליפ טובולרי מתחת ל- 10 מ"מ להפוך לדיספלסיה הוא כ- 2% (1%-4%) לשנה.

  • ההסתברות של דיספלסיה להפוך לגידול היא כ- 5% (2%-10%) לשנה.

Surg Forum. 1963;14:137-138

Scand J Gastroenterol. 1994;29:640-645

Scand J Gastroenterol. 1986;21:853-862

Gastroenterology. 1987; 93:1009-1013

Int. J. Cancer; 2004; 111: 633-639


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Year

dysplasia

cancer

0

4.10%

1.10%

1

5.79%

1.31%

4

10.16%

2.40%

5

11.40%

2.91%

רמת סיכון נוכחית ועתידית

ניתן לחשב את ההסתברות העתידית לדיספלסיה וסרטן.

2

7.36

1.59%

3

8.81%

1.96%


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

מי צודק?

  • פרט צריך לבחור בין כריתה עכשווית של הפוליפ לעומת המתנה ומעקב.

  • האם קיימת אלטרנטיבה דומיננטית?

  • מטילים מטבע הוגנת:

  • חלופה I: אם נקבל "עץ" נקבל 300$ ואם נקבל "פלי" נקבל 400$

  • חלופה II: אם נקבל "עץ" נקבל 100$ ואם נקבל "פלי" נקבל 200$

מהי אלטרנטיבה דומיננטית?


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

>

>

מי צודק?

לא חשוב מה תהיה תוצאת ההגרלה תמיד עדיף לבחור בחלופה I. מצב זה נקרא דומיננטיות חזקה


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

מי צודק?

  • במקרה זה יתכן ומי שבוחר בחלופה II יקבל 350$ ואילו מי שבוחר בחלופה I יקבל "רק" 300$.

  • ברור שחלופה I עדיפה, מצב זה נקרא דומיננטיות סטוכסטית (פותח ע"י חיים לוי מהאוניברסיטה העברית)


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

מי צודק?

  • פרט צריך לבחור בין כריתה עכשווית של הפוליפ לעומת המתנה ומעקב.

  • בבחירה בין שתי האלטרנטיבות האם קיימת אלטרנטיבה דומיננטית? כנראה שלא.

  • אי הנעימות והסיבוכים האפשריים של כריתת פוליפ אינם פוסלים אפשרות של המתנה, רק ל- 2.9% מהחולים שיבחרו המתנה במשך חמש שנים, הפוליפ יתפתח לגידול.

  • לפרטים שונים יתכנו העדפות שונות (מה שהכרחי לקיום שוק)


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

מי צודק?

  • קריטריון חשוב בהתנהגות הוא עקביות (consistency) בהחלטות.

  • האם קיימת עקביות בבחירה של המתנה?

  • כנראה שלא !


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

מי צודק?

  • לאדם בגיל 55 עם סיפור משפחתי של CRC (אביו חלה ב- CRC בגיל 60) האם עדיף לערוך קולונוסקופיה וכריתה בהתאמה או ניתן להמתין?

  • Prevalence של CRC הוא כ- 0.5%, וסיפור משפחתי מגדיל את ההסתברות פי 2-3. הסיכון ל-CRC של אדם זה דומה לסיכון של נבדק שנמצא ב- CTC פוליפ בגודל 8 מ"מ.

  • אם לא נמתין אם האדם עם סיפור משפחתי, אין מקום להמתין עם אדם שנמצא ב- CTC פוליפ בגודל 8 מ"מ.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

מי צודק?

מנקודת מבט ציבורית (קביעת מדיניות) מלבד שקלול של העדפות של הפרטים, חשוב לשקול אילוצים כלכליים ולוגיסטיים בקביעת ההמלצות.


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Faruque Ahmed, Special supplement of the journal CANCER. To be published in summer 2006


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Faruque Ahmed, Special supplement of the journal CANCER. To be published in summer 2006


Is colonoscopy justified for any polyp discovered during computed tomographic colonography ctc

Health Benefits

Health Risks

Decision-Analytic Models


  • Login