Do all colorectal polyps require pathological examination?

AimTo assess whether it is possible to omit the pathological

examination of some polyps without any risk for the patient

2 studies- Retrospective study: retrospective assessment of all polyps removed from September 2003 to August 2008 within the organized gFOBT CRC screening program implemented in the Haut-Rhin (a French administrative district) 0.71 million inhabitants. All residents aged 50-74 invited to participate in a program with biennial gFOBT (Hemoccult II) (Denis B et al Gut 2007)

- Prospective study: prospective assessment of all polyps removed from January to August 2008 in the endoscopy unit of Pasteur Hospital in Colmar

Conclusions- Due to the risk of invasive carcinoma, all polyps > 5 mm require

pathological examination.

- Conversely, the pathological examination of a great number of

polyps ≤ 5 mm can be safely omitted, the proportion depending on

the level of risk that is considered acceptable:

. All polyps ≤ 5 mm associated with a CRC or a polyp ≥ 10 mm or removed

in very old patients without any risk for the patient (15 – 20% of polyps)

. All polyps ≤ 5 mm associated with a polyp 6 - 9 mm with the risk of a 5y

surveillance interval instead of a 3y in one patient out of 175 (10% of polyps)

. All isolated polyps ≤ 5 mm in people with personal or family history of

CRC or adenoma with the risk of a 5y surveillance interval instead of a 3y in

one patient out of 44 (30% of polyps)

Digestive Disease Week, Chicago, 2 June 2009

Background

Médecine A, Hôpital Pasteur; Association pour le Dépistage du Cancer colorectal en Alsace (ADECA Alsace), Colmar, FRANCE

Abstract

Results – retrospective study

Methods

Percentage of correct surveillance intervals

Bernard DENIS, Jacques BOTTLAENDER, Anne Marie WEISS, André PETER, Gilles BREYSACHER, Pascale CHIAPPA, Isabelle GENDRE, Philippe PERRIN

Conflict of interest : none

Pathological examination of removed colorectal polyps places a huge burden on pathologists and represents a non negligible cost. It is of value only if clinical management is affected eg if colorectal cancer (CRC) is detected or if the post-polypectomy surveillance interval is guided. Aim: to assess whether it is possible to omit the pathological examination of some polyps without any risk for the patient.Methods: retrospective assessment of all polyps removed from September 2003 to August 2008 within the organized gFOBT CRC screening program implemented in the Haut-Rhin and prospective assessment of all polyps removed from January to August 2008 in a hospital endoscopy unit. Results: The results of the retrospective study involving 4360 polyps are presented in the table. In the prospective study, 355 polyps were removed during 175 colonoscopic procedures. 47.4% of them were a 1st procedure and 46.5% a surveillance procedure after surgery for CRC or polypectomy. A family history of CRC was present in 13.9% of cases. 263 (74.1%) polyps were ≤ 5 mm and 54 (15.2%) were ≥ 10 mm. 90 (25.7%) polyps were non adenomatous, 76 (21.4%) advanced adenoma and 2 (0.6%) invasive carcinoma. The pathological examination was considered useful by the endoscopist for 148 (41.7%) polyps. This rate of useful examinations varied according to the polyps’ size (26.1% for polyps ≤ 5 mm, 73.7% for 6-9 mm and 92.5% for ≥ 10 mm)(p<0.001) and to the context (57.1% in case of a 1st procedure and 23.4% in case of a surveillance procedure). The pathological examination was necessary for the determination of the surveillance interval in 24.0% of patients and modified the surveillance interval proposed by the endoscopist in 8.6% of patients. It had no impact on the surveillance interval in 67.4% of patients. If isolated polyps ≤ 5 mm had not been examined in patients with either personal or family history of CRC or adenoma (37.5% of polyps in our prospective study) one patient out of 44 would have had a surveillance interval of 5 years instead of 3 years. Conclusion: Due to the risk of invasive carcinoma, all polyps > 5 mm require pathological examination. The pathological examination of diminutive polyps ≤ 5 mm either associated with a CRC or a polyp ≥ 10 mm or removed in very old patients can be omitted without any risk for the patient. They represent 13.8% of polyps in case of a diversified recruitment and 22.3% in an organized gFOBT CRC screening program.

Haut-Rhin

175 colonoscopies- 68 Women – 107 Men- 64.8 y mean age- 1st colo : 47.4%- personal history of CRC or adenoma: 46.5%- 1st degree family history of CRC: 13.9%

- After polypectomy, decisions regarding surgical resection and surveillance intervals are based on pathology findings of the removed specimens. - Pathological examination of all removed colorectal polyps is usually recommended.- However it places a huge burden on pathologists at a non negligible cost. - Furthermore, it is of value only if clinical management is affected eg if invasive carcinoma is detected or if the post-polypectomy surveillance interval is guided.

69 (5.1)

1290 (96.1)

1290 (96.1)

1343 (33.8)

≥ 10 mm

70 (1.6)1 (0.2)0 (0)Invasive cancer n (%)

1748 (40.1)178 (30.2)280 (13.7)Advanced adenoma n (%)

3134 (71.9)483 (82.0)1361 (66.8)Adenomatous polyps n (%)

4360589 (14.8)2038 (51.3)Number n (%)

all6 – 9 mm≤ 5 mmPolyps’ size

Results – prospective study

81,1%

97,1% 99,4% 100% 100%

0%

20%

40%

60%

80%

100%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

% patients with correct

surveillance intervals

% polyps ≤ 5 mm analyzed

Threshold?

Polyps’ size ≤ 5 mm 6 – 9 mm ≥ 10 mm all

Number n (%) 261 (74.6) 35 (10.0) 54 (15.4) 350

Adenomatous polyps n (%) 180 (69.0) 29 (82.9) 51 (94.4) 260 (74.3)

Advanced adenoma n (%) 22 (8.4) 13 (37.1) 51 (94.4) 86 (24.6)

Invasive cancer n (%) 0 (0) 0 (0) 2 (3.7) 2 (0.6)

Endoscopist performances for the diagnosis of malignant polyp

disease

CRC + CRC -

testCRC + 2 59 61

CRC - 0 294 294

2 353 355

- Sensitivity 100% - PPV 3.3%- Specificity 83.0% - NPV 100%

Characteristics of polyps examined

Number of polyps

examined n (%)

Number of patients with

correct surveillance

n (%)

All (> 5 mm and all ≤ 5 mm ) 355 (100) 175 (100)

All except ≤ 5 mm associated with cancer or polyp ≥ 10 mm or very old age

306 (86.2) 175 (100)

Idem above except ≤ 5 mm associated with polyp(s) 6 – 9 mm

276 (77.7) 174 (99.4)

Idem above except isolated ≤ 5 mm polyps in patients with history*

143 (40.3) 170 (97.1)

Idem above except isolated ≤ 5 mm polyps in patients without history* (ie all polyps > 5 mm without any ≤ 5 mm )

92 (25.9) 142 (81.1)

history*: personal or family history of CRC or adenoma

175 pts

42 pts (24.0%)wait for pathol.

133 pts (76.0%)surveillance interval proposed / endoscopist

15 pts (8.6%)surveillance modified / pathol.

118 pts (67.4%)surveillance confirmed / pathol.

2 pts (1.1%)no surveillance

2 pts (1.1%)S.I. lengthened

11 pts (6.3%)S.I. shortened

57,1%

26,8%

1st colo

n colo

92,6%

73,7%

25,9%

> or = 10 mm

6 - 9 mm

< or = 5 mm

Rate of useful pathological examinations: 41.1%