Digestive Endoscopy

(2003)

15

(Suppl.), S36–S38

AIMING FOR SAFE, SURE, SWIFT ESTABLISHMENT OF EMR FOR

COLORECTAL CANCERS

Blackwell Science, LtdOxford, UKDENDigestive Endoscopy0915-56352003 Blackwell Science Asia Pty Ltd

15284

RESIDUAL/RECURRENT LESIONS AFTER EMR FOR EARLY CRCS TANAKA

ET AL.10.1046/j.0915-5635.2003.00284.x

aiming for safe, sure, swift establishment of emr for colorectal cancers3638BEES SGML

Correspondence Shinji Tanaka, Department of Endoscopy,Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima734-8551, Japan. Tel.:

+

81-82-257-5538, Fax:

+

81-82-257-5538. Email: colon@hiroshima-u.ac.jp

ENDOSCOPIC DIAGNOSIS AND TREATMENT OF LOCAL RESIDUAL/RECURRENT LESIONS AFTER ENDOSCOPIC MUCOSAL RESECTION

FOR EARLY COLORECTAL CARCINOMA

S

HINJI

T

ANAKA

,* S

HIRO

O

KA

,* S

HINJI

N

AGATA

,* M

ASANORI

I

TO

,* K

EN

H

ARUMA

†

AND

K

AZUAKI

C

HAYAMA

‡

*

Department of Endoscopy,

‡

First Department of Internal Medicine, Hiroshima University Hospital, Hiroshima, Japan and

†

Department of Gastroenterology II, Kawasaki Medical College, Kurashiki, Japan

Local residual/recurrent lesions have been observed with some frequency after endoscopic mucosal resection (EMR) forcolorectal tumors. Many reports have revealed that the rate of recurrence after piecemeal resection is higher than thatafter

en bloc

resection. Thus, to accomplish an appropriate trimming in EMR, it is important to closely observe the lesionsto be resected, possibly by magnification. Our data show that, with careful trimming of lesions, there are no significantdifferences in rates of local residual recurrence between

en bloc

and piecemeal resections. The manner of recurrence andthe biological characteristics of residual/recurrent tumors depend on whether the resected lesion is an adenoma, carcinomain adenoma,

de novo

carcinoma, mucosal (m) or submucosal (sm) carcinoma. Therefore, it is essential to choose theappropriate method of follow-up observation according to histopathologic findings of resected lesions. In local residual/recurrent lesions of intramucosal carcinomas, the treatment policy should be decided from an overall evaluation ofhistological findings on both recurrent and resected primary lesions. After EMR of sm carcinomas, attention should alwaysbe paid to both the loci of resection and possible metastasis during follow-up observation; surgical treatment is inevitablein the case of recurrence.

Key words: early colorectal carcinoma, EMR, local recurrence.

INTRODUCTION

The indications for endoscopic mucosal resection (EMR)have been extended, based on advances in endoscopic instru-ments and technology, and detailed clinicopathologic analy-ses of the large number of cases accumulated. Furthermore,advances in diagnostics, such as high-resolution video-endoscopy, magnifying endoscopy and endoscopic ultra-sonography (EUS) employing miniature probes, have madeit easier to predict possible sites of submucosal (sm) invasionwithin a whole lesion, and ‘planned’ piecemeal resection toavoid fragmentation of sm sites is now established. Recently,EMR has been vigorously applied to large lesions such aslaterally spreading tumor (LST) and several sm carcinomasthat satisfy certain requirements.

1

However, local residual/recurrent lesions still appear after EMR with some fre-quency, and an early diagnosis and appropriate additionaltreatment for the lesions are essential. In this article, wedescribe the nature and problems of local residual/recurrentlesions after EMR for colorectal tumors, and discuss theclinical diagnosis and additional therapeutic methods forsuch lesions with emphasis on endoscopy.

ACTUAL STATE AND PROBLEMS OF LOCAL RESIDUAL/RECURRENT TUMORS

AFTER EMR

There have been a number of reports on local residual/recur-rent lesions after EMR for intramucosal tumors in the colon.Kobayashi

et al

.

2

demonstrated that the rate of local residualrecurrence of adenoma or mucosal (m) carcinoma after endo-scopic resection was 0.7% and that the rate was significantlyhigher for the lesions with a diameter of

>

30 mm or afterpiecemeal resection (0.3% for

<

30 mm

vs

25% for

=

30 mm).Ohta

et al

.

3

also reported that the rate of residual recurrencewas higher for cases with piecemeal resection in comparisonwith

en bloc

resection, and Igarashi

et al

.

4

showed that therate of residual recurrence was significantly higher for thelesions with a diameter of

>

21 mm (2.2% for

<

20 mm

vs

14.3% for

=

21 mm). Furthermore, Matsunaga

et al

.

5

reportedthat the rate of local residual recurrence after piecemealresection was higher than that after

en bloc

resection.We investigated the rate of local residual recurrence for

LST with diameters equivalent to 10 mm, which would makethem potential candidates for piecemeal resection, afterbeing diagnosed for radical cure by EMR (the overall recur-rent rate, 2%). Different from the findings noted above, theresults from our department showed that there were no sig-nificant differences in the rate of local residual recurrencebetween

en bloc

and piecemeal resections, although the rateof local residual recurrence tended to be higher for lesionswith a larger diameter (Table 1). In addition, all of the local

RESIDUAL/RECURRENT LESIONS AFTER EMR FOR EARLY CRC S37

residual/recurrent lesions were intramucosal, and were com-pletely cured by additional endoscopic treatments. Asdescribed by Kudo

et al

.

6

the rate of local residual recurrencein our department’s cases was markedly reduced followingthe introduction of a magnifying observation method forresected lesions (Table 2). Local residual/recurrent lesionsafter EMR for intramucosal tumors are in many casesthought to be generated from residues produced duringresection of the periphery of primary lesions, whether it is

enbloc

or piecemeal resection.

7

We believe that recurrence canbe prevented by close observation, possibly by magnification,of the locus to be resected, and trimming by hot biopsy orcauterization; but just as long as the degree of difficulty inEMR does not exceed the abilities of the operators.

7

Totalresection procedures for large lesions with an IT-knife or aHook knife have recently been developed, but it seemsmeaningless to adhere to

en bloc

resection for all LSTs, mostof which are carcinomas in adenoma, because the operationtakes a long time and the operative technique is most diffi-cult. Instead, planned piecemeal resection would be suffi-cient for radical cure of such lesions. Total resection using anIT-knife or a Hook knife should be limited to lesions such aslarge

de novo

carcinomas that should not be treated by piece-meal resection.

Local residual/recurrent lesions after EMR for sm carci-noma sometimes appear as advanced carcinomas or metasta-sis to the lymph nodes or liver, which directly affects a vitalprognosis. Recent results from analyses of large numbers ofthe cases with colorectal sm carcinomas have clarified severalrequirements for non-metastatic sm carcinomas. In EMR,however, the complete excision of an sm carcinoma that givesa negative surgical margin is essential. Even if EMR speci-mens are judged to be completely resected, invasion maysometimes progress discontinuously into deeper regions inthose cases in which the invasive front is poorly differenti-ated, sprouting, or shows vessel involvement. Thus, it is ofcritical importance to make a correct diagnosis of curabilityby undertaking a precise and close examination of resectedspecimens.

CLINICAL DIAGNOSIS OF LOCAL RESIDUAL/RECURRENT LESIONS AFTER EMR

Local residual/recurrent lesions and metastatic lesions withinthe colic wall or into associated lymph nodes and multipleorgans should be treated separately.

Local residual recurrence of intramucosal tumors

In cases of intramucosal tumors, it is possible to detect evenvery small residues on the resected ulcer floor and its periph-ery by magnifying endoscopy immediately after EMR. Aslong as residual tumors left in the periphery are not artifi-cially embedded in the submucosa immediately after resec-tion by some careless means, such as a casual clip ligation,the manner of recurrence would principally be intramucosalprotrusion near any ulcer scars, when local small residuallesions within an intramucosal tumor are being followed up.

In practical diagnoses, it is necessary to change follow-upexamination intervals according to whether the periphery ofan EMR specimen is an adenoma (carcinoma in adenoma)or a carcinoma (

de novo

carcinoma). We perform a colono-scopic re-examination of the cases showing a positive surgicalmargin in EMR after 3–6 months. If local residual/recurrentlesions are detected within this period, they can be com-pletely cured by additional treatment with endoscopy.

Local residual recurrence and metastatic recurrence of sm carcinomas

When EMR is performed for sm carcinomas, just undertak-ing follow-up observation of a resected locus by colonoscopywould be insufficient. Systemic inspection, including that ofdeeper local regions, lymph nodes and liver should be carriedout utilizing tumor marker testing such as CEA, externalultrasonography, CT scan, and in some cases EUS.

TREATMENT OF LOCAL RESIDUAL/RECURRENT LESIONS AFTER EMR

Local residual lesions of intramucosal tumors

When recurrent lesions are found, the degree of histologicalatypia of the lesions should be determined by pit patterndiagnosis employing magnifying endoscopy or forcepsbiopsy. Histopathologic findings on a positive surgical margin

Table 1.

Prevalence of local residual/recurrent lesions afterEMR in each method between January 1990 and June 2001

Gross type Resection methods Diameter of lesion (mm)

Total

10–19 20–29

>

30

F-LST en bloc 1.2% 0% 0% 1.0%2/173 0/33 0/2 2/208

piecemeal 0% 0% 0% 0%0/15 0/9 0/9 0/33

G-LST en bloc 1/0% 2.3% 7.1% 1.9%1/98 1/44 1/14 3/156

piecemeal 0% 0% 6.0% 4.3%0/14 0/19 5/83 5/116

F-LST, flat type laterally spreading tumor; G-LST, granulonodulartype laterally spreading tumor.

Table 2.

Prevalence of local residual/recurrent lesions afterEMR in each method between January 1997 and June 2001

Gross type Resection methods Diameter of lesion (mm)

Total

10–19 20–29

>

30

F-LST en bloc 0.8% 0% 0% 0.7%1/128 0/22 0/2 1/152

piecemeal 0% 0% 0% 0%0/10 0/6 0/4 0/20

G-LST en bloc 0% 0% 0% 0%0/78 0/38 0/8 0/124

piecemeal 0% 0% 1.9% 1.4%0/9 0/12 1/52 1/73

F-LST, flat type laterally spreading tumor; G-LST, granulonodulartype laterally spreading tumor.

S38 S TANAKA

ET AL.

in the periphery of a primary focus after EMR will give usefulinformation. If a local residual/recurrent lesion is an ade-noma or a carcinoma with low grade atypia, additional resec-tion (hot biopsy or cauterization if required) of the lesionwould be sufficient. In cases of carcinoma with high gradeatypia, it is desirable to ascertain the condition of the deeperregions by additional EUS or X-ray radiography, and to com-pletely achieve additional EMR by using a 2-channel scope,an IT-knife, or a Hook knife; enabling a precise histopatho-logic diagnosis. When carcinomas with high grade atypia aredifficult to be treated by additional EMR, local resection orlymph node dissection by laparoscopic operation may benecessary.

Local residual and metastatic recurrent lesions of sm carcinomas

In the cases of local residual or metastatic recurrence of smcarcinomas, additional surgical excision including lymphnode dissection is essential after the close inspection of thewhole body. The conditions might also necessitate adjuvantchemotherapy.

CONCLUSIONS

To prevent local residual/recurrent lesions, it is important notto attempt to perform EMR that exceeds the technical abilityof the operators. Evaluation of EMR specimens and carefulobservation of loci of resection immediately after EMR, aswell as adequate follow-up observation at appropriate inter-

vals, are required. In addition, precise qualitative diagnosisof local residual/recurrent lesions after EMR should be madefor appropriate additional therapies.

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