1 Is Colonoscopy Justified for Any Polyp Discovered During Computed Tomographic Colonography (CTC)? Am J Gastroenterol 2005;100:1903–1908.

1

Is Colonoscopy Justified for Any Polyp Discovered

DuringComputed Tomographic

Colonography (CTC)?

Is Colonoscopy Justified for Any Polyp Discovered

DuringComputed Tomographic

Colonography (CTC)?

Am J Gastroenterol 2005;100:1903–1908

2

Douglas K. Rex, M.D.

David F. Ransohoff, M.D.

Edgar Achkar, M.D.


3

Douglas K. Rex, M.D.


4

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.

• 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 !!!

5

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.

• 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?

7

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.

• 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.

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

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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.

• 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

9

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.

• 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.

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• 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.

• 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.

SUMMARIZING WHY SHOULD POLYPS BE REMOVED

11

David F. Ransohoff, M.D.


12

• 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?”

• 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?”

Polyp Size and Cancer Risk

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• 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”

• 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”

Cancer Risk – Other Fields

14

• 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

• 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

Other Factors Affecting Decision Making

15

• 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.

• 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.

Decision Making about Prostate Cancer Screening.

• 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.

• 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.

17

• 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.

• 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.

The Future

18

Edgar Achkar, M.D.


19

• 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.

• 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.

CON

20

• 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).

• 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).

PRO

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• 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.

• 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.

BALANCE

22

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

הפוליפ?

האם יש אי הסכמה על הנתונים?

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

הפוליפ?

האם יש אי הסכמה על הנתונים?

דיון

23

Ellsberg Paradox

כדורים 60ו- אדום כדורים בצבע 30בכד יש כחול וחלקם בצבע ירוק חלקם בצבע

בוחרים באופן אקראי כדור



אדומים 30 ירוקים 60

וכחולים

:צריך לבחור בין שתי החלופות הבאות

, כדור בצבע אחר 100$ נקבל אדוםאם נקבל כדור א-0$נקבל

, כדור בצבע אחר 100$ נקבל כחולאם נקבל כדור ב-0$נקבל


, כדור בצבע אחר 100$ נקבל אדוםאם נקבל כדור א-0$נקבל

, כדור בצבע אחר 100$ נקבל כחולאם נקבל כדור ב-0$נקבל

בעיית החלטה I:

24

Ellsberg Paradox






, אם נקבל כדור 100$ נקבל ירוק או אדוםאם נקבל כדור א-0$ נקבל כחול

, אם נקבל כדור 100$ נקבל כחול או ירוקאם נקבל כדור ב-0$ נקבל אדוםבצבע


, אם נקבל כדור 100$ נקבל ירוק או אדוםאם נקבל כדור א-0$ נקבל כחול

, אם נקבל כדור 100$ נקבל כחול או ירוקאם נקבל כדור ב-0$ נקבל אדוםבצבע

בעיית החלטה II:

אדומים 30 ירוקים 60

וכחולים

25

Ellsberg Paradox

30 Balls

60 Balls

Game Red Blue Green

I1 $100 $0 $0

I2 $0 $100 $0

II1 $100 $0 $100

II2 $0 $100 $100

26

Ellsberg Paradox

רוב האנשים בוחרים א' ואילו Iבבעיית ההחלטה רוב האנשים בוחרים ב'.IIבבעיית ההחלטה רוב האנשים בוחרים א' ואילו Iבבעיית ההחלטה רוב האנשים בוחרים ב'.IIבבעיית ההחלטה

מקבל החלטות שמעדיף חלופה א' סבור • )אחרת 30 קטן מ- הכחוליםשמספר הכדורים

היה בוחר חלופה ב'(

מקבל החלטות שמעדיף חלופה ב' סבור • ולכן 30 קטן מ- הירוקיםשמספר הכדורים

)אחרת 30 גדול מ-הכחוליםמספר הכדורים היה בוחר חלופה א'(

מקבל החלטות שמעדיף חלופה א' סבור • )אחרת 30 קטן מ- הכחוליםשמספר הכדורים

היה בוחר חלופה ב'(

מקבל החלטות שמעדיף חלופה ב' סבור • ולכן 30 קטן מ- הירוקיםשמספר הכדורים

)אחרת 30 גדול מ-הכחוליםמספר הכדורים היה בוחר חלופה א'(

סתירהסתירה

27

רמת סיכון (הסתברות) נוכחי•

רמת סיכון (הסתברות) עתידי•

קבלת החלטות מנקודת מבט אישית•

קבלת החלטות מנקודת מבט ציבורית •(מדיניות)





דיון

28

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.

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

30

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.

• 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

31

Current Risk


32

Current Risk


33

Current Risk


35

• 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.

• 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

Current Risk

37

• 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

• 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

Current Risk

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

38

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

• 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.

Current Risk

39

• 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.

• 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

Current Risk

40

• 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

• 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

Meta Analysis

41









דיון

42

6-9בהנחה שידוע שגודל הפוליפ בין •מ"מ. מה ההסתברות שנמצא סרטן

לאחר שנה, לאחר שנתיים ולאחר שלוש שנים.

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

6-9בהנחה שידוע שגודל הפוליפ בין •מ"מ. מה ההסתברות שנמצא סרטן

לאחר שנה, לאחר שנתיים ולאחר שלוש שנים.

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

רמת סיכון בעתיד

43

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

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

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

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

רמת סיכון בעתיד

Surg Forum. 1963;14:137-138Scand J Gastroenterol. 1994;29:640-645Scand J Gastroenterol. 1986;21:853-862Gastroenterology. 1987; 93:1009-1013Int. J. Cancer; 2004; 111: 633-639

44

ניתן לחשב את ההסתברות העתידית לדיספלסיה וסרטן.ניתן לחשב את ההסתברות העתידית לדיספלסיה וסרטן.

רמת סיכון נוכחית ועתידית

1.96%8.81%3

1.59%7.362

cancerdysplasiaYear

1.10%4.10%0

1.31%5.79%1

2.40%10.16%4

2.91%11.40%5

45

?מהי אלטרנטיבה דומיננטית?מהי אלטרנטיבה דומיננטית

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

האם קיימת אלטרנטיבה דומיננטית?•


האם קיימת אלטרנטיבה דומיננטית?•

מי צודק?

מטילים מטבע הוגנת:•

ואם נקבל 300$: אם נקבל "עץ" נקבל Iחלופה •400$"פלי" נקבל

ואם נקבל 100$: אם נקבל "עץ" נקבל IIחלופה •200$"פלי" נקבל

מטילים מטבע הוגנת:•

ואם נקבל 300$: אם נקבל "עץ" נקבל Iחלופה •400$"פלי" נקבל

ואם נקבל 100$: אם נקבל "עץ" נקבל IIחלופה •200$"פלי" נקבל

46

מי צודק?

לא חשוב מה תהיה תוצאת ההגרלה תמיד עדיף . מצב זה נקרא דומיננטיות חזקהIלבחור בחלופה

לא חשוב מה תהיה תוצאת ההגרלה תמיד עדיף . מצב זה נקרא דומיננטיות חזקהIלבחור בחלופה

II I חלופההסתברות

100$ 300$ ½

200$ 400$ ½

>>

47

מי צודק?

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

עדיפה, מצב זה נקרא Iברור שחלופה • (פותח ע"י חיים לוי דומיננטיות סטוכסטית

מהאוניברסיטה העברית)

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

עדיפה, מצב זה נקרא Iברור שחלופה • (פותח ע"י חיים לוי דומיננטיות סטוכסטית

מהאוניברסיטה העברית)

II I חלופההסתברות

200$ 300$ ½

350$ 400$ ½

48


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

אי הנעימות והסיבוכים האפשריים של כריתת •פוליפ אינם פוסלים אפשרות של המתנה, רק ל-

מהחולים שיבחרו המתנה במשך חמש שנים, 2.9%הפוליפ יתפתח לגידול.

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


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

אי הנעימות והסיבוכים האפשריים של כריתת •פוליפ אינם פוסלים אפשרות של המתנה, רק ל-

מהחולים שיבחרו המתנה במשך חמש שנים, 2.9%הפוליפ יתפתח לגידול.

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

מי צודק?

49

קריטריון חשוב בהתנהגות הוא עקביות •)consistency(.בהחלטות

האם קיימת עקביות בבחירה של המתנה? •

כנראה שלא !•

קריטריון חשוב בהתנהגות הוא עקביות •)consistency(.בהחלטות

האם קיימת עקביות בבחירה של המתנה? •

כנראה שלא !•

מי צודק?

50

מי צודק?

(אביו CRC עם סיפור משפחתי של 55לאדם בגיל •) האם עדיף לערוך 60 בגיל CRCחלה ב-

קולונוסקופיה וכריתה בהתאמה או ניתן להמתין?

•Prevalence של CRC -וסיפור 0.5% הוא כ ,. הסיכון 2-3משפחתי מגדיל את ההסתברות פי

של אדם זה דומה לסיכון של נבדק שנמצא CRCל- מ"מ.8 פוליפ בגודל CTCב-

אם לא נמתין אם האדם עם סיפור משפחתי, אין • פוליפ CTCמקום להמתין עם אדם שנמצא ב-

מ"מ.8בגודל

(אביו CRC עם סיפור משפחתי של 55לאדם בגיל •) האם עדיף לערוך 60 בגיל CRCחלה ב-

קולונוסקופיה וכריתה בהתאמה או ניתן להמתין?

•Prevalence של CRC -וסיפור 0.5% הוא כ ,. הסיכון 2-3משפחתי מגדיל את ההסתברות פי

של אדם זה דומה לסיכון של נבדק שנמצא CRCל- מ"מ.8 פוליפ בגודל CTCב-

אם לא נמתין אם האדם עם סיפור משפחתי, אין • פוליפ CTCמקום להמתין עם אדם שנמצא ב-

מ"מ.8בגודל

51

מי צודק?

מנקודת מבט ציבורית (קביעת מדיניות) מלבד שקלול של העדפות של הפרטים, חשוב לשקול

אילוצים כלכליים ולוגיסטיים בקביעת ההמלצות.

מנקודת מבט ציבורית (קביעת מדיניות) מלבד שקלול של העדפות של הפרטים, חשוב לשקול

אילוצים כלכליים ולוגיסטיים בקביעת ההמלצות.

52Faruque Ahmed, Special supplement of the journal CANCER. To be published in summer 2006

53Faruque Ahmed, Special supplement of the journal CANCER. To be published in summer 2006

54

Decision-Analytic Models

Health Risks

Health Benefits

1 Is Colonoscopy Justified for Any Polyp Discovered During Computed Tomographic Colonography (CTC)? Am J Gastroenterol 2005;100:1903–1908.

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