Adénomes bénins et adénomes dégénérés du côlon. Expérience de 12 ans de polypectomie...

Ad6nomes b6nins et ad6nomes d6g6n6r6s du c61on. Exp6r ience de 12 ans de polypectomie endoscopique

F . P . R O S S I N I , A . F E R R A R I , S. C O V E R L I Z Z A *, M . S P A N D R E , M . R I S I O *, C . G E M M E , C. C A V A L L E R O

* G a s t r o e n t e r o l o g y , G a s t r o i n t e s t i n a l E n d o s c o p y S e r v i c e , S u r g i c a l P a t h o l o g y S e r v i c e D e p t . o f O n t o l o g y , O s p e d a l e S. G i o v a n n i , T o r i n o ( I t a l y )

Adenomas and adenomas containing carcinoma of the large bowel. 12 years experience in endoscopic polypectomy

RI~SUMI~

Les ad6nomes porteurs d'un carcinome invasif constituent la majorit6 des cancers colo-rectaux au d6but. Au cours des douze derni6res ann6es, 3 600 polypes ont 6t6 r6s6qu6s par voie coloscopique chez 1 936 patients.

69 adEnomes porteurs d'un carcinome invasif ont 6t6 d6cel6s chez 69 patients. Les param6tres histopathologiques rendent possible la distinction entre les c a s h haut et /t faible risque de m6tastases

lymphatiques. Une comparaison a 6t6 6tablie entre la polypectomie endoscopique seule chez les patients ~ faible risque, et la chirurgie chez

les patients ~ haut risque. 52 cas ~ risque faible ont 6t6 trait6s par polypectomie endoscopique sans chirurgie ; 17 malades ont subi une intervention

chirurgicale. Aucune m6tastase ~t distance n'a 6t6 objectiv6e dans le groupe polypectomis6 ; des ganglions lymphatiques m6tastatiques ont

6t6 trouv6s apr~s intervention chez 40 % des patients ~ haut risque. Ces r6sultats confirment l'attitude thfrapeutique adopt6e chez les patients ~ faible risque ; par contre chez les patients ~ haut

risque, une 6valuation histo-pathologique soigneuse est indispensable.

S U M M A R Y

Adenomas containing invasive carcinoma are the majority o f early colorectal cancers. In the last 12 years about 3 600 polyps have been removed by colonoscopic polypectomy in 1 936 patients. 69 adenomas containing invasive carcinoma have been found in 69 patients. Pathological parameters make it possible to distinguish between high and low risk cases o f limphnode metastases. Endoscopic polypectomy alone in low risk patients has been compared to major surgery in high risk cases. 52 low risk cases have been treated only by E.P. ; 17 patients underwent surgery. No distant metastases have been so far evidenced in the polypectomy group ; limphnode metastases have been found at operation

in 40 % o f high risk cases.

The observed results confirm the value o f the actual therapeutic policy in low risk patients ; in high risk cases a careful pathological evaluation is mandatory.

Au cours des quinze derni~res ann6es, il a 6t6 d6montr6 que la polypectomie endoscopique au niveau du c61on permet : l'ex6r6se radicale des polypes, un diagnostic histologique pr6cis, la d6monstration de la dysplasie, la r6section des 16sions n6oplasiques, et enfin l'interruption de la s6quence ad6nome-carcinome [1, 2, 3, 4, 5, 6].

En fait, la majorit6 des cancers colo-rectaux se d6veloppent au d6part d'un ad6nome [2, 7, 8, 9].

Au cours d'une p6riode de douze ans, environ 3 600 polypes ont 6t6 enlev6s par polypectomie endoscopique (P.E.) chez 1 396 patients. Si l'on

exclut les ex6r6ses de polypes r6alis6es au niveau du c61on restant chez des patients atteints de polypose familiale, environ 80 % des polypes r6s6qu6s 6taient des ad6nomes sporadiques simples ou multiples.

Actuellement, les probl~mes techniques de la P . E . s o n t p r e s q u e c o m p l 6 t e m e n t r 6 s o l u s , m a i s l e s l im i t e s d e la m 6 t h o d e d o i v e n t 6 t re p r 6 s e n t e s l ' e s p r i t l o r s q u ' o n g a r a n t i t u n e e x 6 r ~ s e e n d o s c o p i - q u e r a d i c a l e .

Plusieurs facteurs restreignent l'emploi de cette technique, parmi lesquels une pr6paration insuffi-

Tir6s ~ par t : Prof. F.P. ROSSINI, Gastroenterology, Gas- trointestinal Endoscopy Service, Dept. of Oncology, Ospedale S. Giovanni, Via Cavour 31, 10123 Torino (Italy).

Mots-cl#s : ad6nomes, ad6nomes d6g6n6r6s, c61on, polypectomie endoscopique.

Key-words : adenoma, adenoma containing carcinoma, colon, endoscopic polypectomy.

Acta Endoscopica Volume 17 N ~ 3 - 1987 137

sante de l 'intestin, un mat6riel endoscopique ina- d6quat et une morphologie particuli6re du colon. Avant chaque polypectomie , la forme, la localisation, la dimension et le nombre de polypes doi- vent 6tre consid6r6s comme des facteurs limitatifs possibles de la m6thode [10].

Deux questions demeuren t en suspens :

- - l a d6finition des protocoles de surveillance apr6s polypectomie ;

- - la conduite th6rapeut ique apr6s r6section d 'ad6nomes contenant un carcmome invasif (A.C.C.I . ) .

La programmat ion et la conduite des sch6mas de surveillance est parfois difficile en raison de probl6mes d 'organisat ion, de la compliance des patients et de la possibilit6 d 'accepter un nombre croissant de malades, m~me avec l 'aide d 'un sup- port informatique.

D'apr6s notre exp6rience, 30 % des malades se soumet tent tt des examens de contr61e r6guliers : le taux de nouveaux ad6nomes ainsi d6couverts est environ de 1 1 % .

Chez les malades por teurs de 2 ~ 3 ad6nomes pr6c6demment enlev6s par P .E . , ce taux s'616ve 18 % et il est de 24 % dans les cas de polypes multiples sporadiques [11]. A l 'avenir, il sera n6cessaire de d6finir clairement les param~tres uti- lis6s dans un p rogramme de survei l lance: pr6ci- sion avec laquelle un c61on est consid6r6 comme ,, nettoy6 ~ de toute format ion polypoide, crit~res fond6s sur l'glge du patient , l 'histoire de la famille, le type histologique des polypes r6s6qu6s, le nombre d 'ad6nomes, leur localisation, leur taille, leur morphologie, le degr6 de dysplasie de chaque ad6- nome, ceci afin de distinguer un groupe ~ risque d 'ad6nomes m6tachroniques et de cancers (glg6s de plus de 40 ans, r6section d 'ad6nomes multiples) et d 'autre part un groupe ~ risque faible (fige inf6- rieur h 40 ans, r6section d 'un ad6nome isol6).

Dans le premier cas, les examens de contr61e seront appliqu6s de faqon stricte, avec un intervalle de deux ans, alors que dans le second groupe, l ' intervalle pourra i t ~tre port6 ~ quatre ans [11, 12, 13].

Le probl~me des ad6nomes contenant un cancer invasif (A.C.C. I . ) , lesquels consti tuent la majori t6 des cancers pr6coces du colon - - selon la classifi- cation de I 'O.M.S. [24] - - , a 6t6 6tudi6 de fa~on syst6matique afin d 'arr6ter un programme correct de surveillance th6rapeut ique fond6 sur le risque m6tastasique.

Un ad6nome contenant un cancer invasif est class6 comme tel s'il y a 6vidence histologique d 'un envahissement de la sous-muqueuse ~ travers la muscularis mucosae [9, 14, 15].

Des ad6nomes canc6ris6s peuvent diss6miner par voie sanguine ou lymphat ique. Alors qu 'une diss6- mination h6matog~ne est incontr6lable, le risque d 'envahissement des ganglions lymphatiques doit

6tre pris en compte dans le choix entre P.E. et r6section chirurgicale.

Plusieurs facteurs influencent ie risque m6tastasi- q u e : envahissement vasculaire, dimensions de la tumeur, degr6 de diff6renciation ; la fr6quence des m6tastases augmente avec la taille de la tumeur et l 'anaplasie [3, 15, 16, 17, 18].

Des emplois n6oplasiques dans les vaisseaux lymphatiques ou velneux augmentent ie risque m6tastatique [15].

Ces crit~res morphologiques permet tent de clas- ser les ad6nomes avec cancer invasif en deux groupes respect ivement ~ faible et haut risque de m6tastases ( tableau I) [2, 5, 8, 15, 16, 19].

TABLEAU I

PARAMI~TRES HISTOLOGIQUES DES ADI~NOMES AVEC CANCER INVASIF

A faible risque A haut risque

1. Ad6nocarcinome et ad6nocarcinome mucineux bien diff6renci6 ou mod6r6ment diff6renci6.

1. Ad6nocarcinome et ad6nocarcinome mucineux peu diff6renci6.

2. Cancer avec cellules en bague h chaton.

3. Cancer indiff6renci6. 4. Ad6nocarcinome bien ou

mod6r6ment diff6renci6 avec des foyers de 1-2-3.

5. Envahissement lymphatique ou vasculaire.

La tranche de section doit 6tre situ6e en tissu sain.

Les patients h haut risque sont soumis h u n trai tement chirurgical ; les patients h faible risque sont soumis ~ une surveillance endoscopique, 6ventuellement th6rapeut ique dans le cadre d 'un sch6ma pr6-6tabli.

Notre exp6rience compare la valeur de la P.E. chez les patients h faible risque, et le t rai tement chirurgical chez les malades h haut risque.

M A T E R 1 E L E T M E T H O D E S

Sur 2 295 ad6nomes du c61on r6s6qu6s par P .E. , 69 polypes avec cancer invasif ont 6t6 observ6s chez 69 malades (3 %).

Les A.C.C. I . dans la polypose familiale, chez les patients avec cancer synchrone, les polypectomies avec f ragmentat ion, cas dont l 'envahissement carcinomateux est douteux , ont 6t6 exclus de la pr6sente 6tude.

Sur les 69 patients, 17 ont 6t6 op6r6s : 5 ont 6t6 exclus de l '6tude en raison d 'un 6tablissement ina- d6quat des param~tres morphologiques , 2 ont 6t6 soumis h la chirurgie bien que les param6tres histologiques et endoscopiques aient indiqu6 un risque faible de m6tastases.

138 V o l u m e 17 - N ~ 3 - 1987 A c t a E n d o s c o p i c a

10 malades ont 6t6 op6r6s sur la base d'un diagnostic histologique de A.C.C. I . ~ haut risque.

Le groupe r6siduel de 52 patients ~ faible risque a 6t6 trait6 par P.E. et est entr6 dans le sch6ma de surveillance.

Ce sch6ma de surveillance de patients h haut risque comprend [4, 5] :

- - au moment du diagnostic : une ultrasonogra- phie h6patique, tests biologiques h6patiques, examen complet sanguin (comptage globulaire, VS, CEA) ;

- - apr6s six mois : examen radiologique en double contraste en pancoloscopie ;

- - c h a q u e ann6e : pancoloscopie et/ou examen radiologique en double contraste , radiographie de thorax, ul trasonographie h6patique, tests biologiques h6patiques, examen h6matologique, VS, CEA.

Le groupe des patients h haut risque a subi des contr61es post-op6ratoires selon un sch6ma con- forme ~ celui appliqu6 dans le cancer colo-rectal [2O].

R E S U L T A T S

Les patients por teurs d 'A .C.C. I . ~ haut risque trait6s par chirurgie apr~s P.E. ont un ~ge moyen de 58,9 ans (limites 47-69 a n s ) ; la proport ion hommes-femmes est de 3:2 ; la localisation colique la plus fr6quente est le sigmoide.

La morphologie des A .C .C. I . est la suivante : sessiles : 50 %, p6dicul6s : 50 %.

Le diam~tre moyen 6tait de 1,9 cm (limites : 1-3 cm), le type histologique 6tait ad6no-tubulaire dans 8 cas sur 10, tubulo-villeux dans 2 cas.

Selon les crit6res histologiques de I 'O.M.S. [14], les cancers invasifs ont 6t6 class6s en mod6r6ment diff6renci6s (7 cas), et peu diff6renci6s (3 cas).

Sur 7 polypes, un envahissement vasculaire a 6t6 mis en 6vidence.

La r6section par P.E. respectait une tranche de section saine dans 6 cas, contenai t du tissu carcinomateux dans 2 cas. L' i lot d' invasion carcinoma- teuse 6tait en contact direct avec la zone de n6crose post-coagulation sur la tranche de section dans 2 cas.

Sur toutes les pi6ces op6ratoires, la zone de polypectomie ant6rieure a 6t6 ident i f i6e; dans aucun cas, il ne fut t rouv6 de tissu ad6nomateux ou carcinomateux, y compris chez les 2 patients dont la tranche de section 6tait envahie.

Pour tant dans ces deux cas, du tissu canc6reux 6tait th6or iquement laiss6 en place au niveau de la paroi colique, mais p robab lement il fut d6truit par la coagulation au cours de la P.E.

Acta Endoscopica

Dans un cas, un petit vaisseau extramural 6tait envahi.

Le nombre de ganglions lymphat iques p6ri-coli- ques a vari6 selon l '6tendue de la r6section.

Chez 4 patients (40 %), des m6tastases lymphatiques ont 6t6 mises en 6vidence (respect ivement une sur 26 ganglions, une sur 31, une sur 13 et deux sur 4).

Un pat ient est d6c6d6 d 'embol ie pulmonaire 4 jours apr~s l ' intervention ; un autre patient des suites d 'une cirrhose h6pat ique un an apr6s l 'op6- ration.

Chez 5 sur les 8 patients restants, la p6riode de surveillance d6passe 3 ans.

Dans 3 cas, des ad6nomes synchrones ont 6t6 d6couverts ; 3 cas ont d6velopp6 des ad6nomes m6tachrones.

Jusqu 'h pr6sent, aucune m6tastase h distance n'a 6t6 object iv6e par ul t rasonographie ou radiographie.

Dans les 2 cas ~ faible risque soumis ~ la chirurgie, aucune diss6mination locale ou h distance n 'a 6t6 d6couverte h l ' intervention.

Les caract6res cliniques et pathologiques des 52 malades por teurs d 'A .C.C. I . ~ faible risque et trait6s par P .E. sont les suivants : l 'hge moyen est de 66,5 ans (limites 38-91 ans), le rappor t hommes-femmes : 2,2:1 ; la localisation colique la plus f r6quente est le sigmoide ; le diam6tre moyen est de 2,2 cm (limites : 0,5-4 cm) ; 80 % des polypes sont p6dicul6s.

Des ad6nomes synchrones ont 6t6 mis en 6vi- dence chez 22 patients (44,9 %) , sur un nombre total de 48 ad6nomes, avec un nombre individuel pouvant varier de 1 h 9 polypes par pat ient ; 50 % des cas (26 sur 52) ont 6t6 suivis pendant une p6riode de plus de 3 ans (jusqu'~ 5 ans dans 3 cas, 7 ans dans 2 cas).

11 patients ont d6velopp6 un ou plusieurs ad6- nomes m6tachrones au cours de la p6riode de surveillance ( t o t a l : 24 ad6nomes) , 2 patients ont pr6sent6 des polypes hyperplasiques ; 2 cas de cancers m6tachrones (un localis6 au caecum, 3 ans apr~s P .E. pour A.C.C. I . du c61on sigmoide ; le second au niveau du rectum, 4 ans apr~s P.E. pour A .C .C. I . au niveau du c61on sigmoide). Un pat ient est d6c6d6 de cancer pancr6at ique apr6s 5 arts.

Dans aucun cas, des m6tastases a distance n 'ont 6t6 d6montr6es par les examens radiographiques et ul t rasonographiques.

D I S C U S S I O N

Dans notre s6rie de polypectomies endoscopiques, 3 % des ad6nomes mont ren t un foyer de

Volume 17 N ~ 3 - 1987 139

c a r c i n o m e invas i f . C e t t e p r o p o r t i o n s ' insc r i t dans les v a l e u r s d e la l i t t r r a t u r e r a p p o r t r e s p o u r les dix d e r n i r r e s a n n r e s , va r i an t de 1,9 % h 9,4 % [1, 2, 5, 8, 13, 15, 21, 22, 23, 24, 25, 26, 27, 28, 29].

L ' r v a l u a t i o n du r i sque de d i s s r m i n a t i o n l y m p h a - t i q u e d r t e r m i n e le cho ix t h r r a p e u t i q u e p o u r les m a l a d e s p o r t e u r s d ' A . C . C . I . U n c a n c e r p e u d i f f r - r e n c i r , u n e i nvas ion va scu l a i r e , un e n v a h i s s e m e n t de la t r a n c h e de s ec t ion [3, 15, 16, 17, 18] const i - t u e n t les p a r a m r t r e s h i s t o l o g i q u e s de A . C . C . I . h a u t r i sque .

C e r t a i n s a u t e u r s on t 6 g a l e m e n t insist6 sur la m o r p h o l o g i e c o m m e cr i t~re d ' i n c l u s i o n dans ie g r o u p e h h a u t r i sque [19, 28, 30].

D a n s n o t r e s6r ie d ' A . C . C . I . ~ h a u t r i sque , les p o l y p e s 6 t a i en t r e s p e c t i v e m e n t sess i les d a n s 50 % et p r d i c u l r s d a n s les 50 a u t r e s p o u r c e n t ; les enva- h i s s e m e n t s g a n g l i o n n a i r e s on t 6t6 t r o u v r s su r 2 p o l y p e s sess i les e t sur 2 p o l y p e s p r d i c u l 6 s .

L e s p a t i e n t s h hau t r i sque o n t 6t6 s o u m i s au t r a i t e m e n t ch i ru rg ica l : b i en q u ' a u c u n t issu a d r n o - m a t e u x ou c a r c i n o m a t e u x n ' a i t 6t6 t r ouv6 h l ' i n t e r - v e n t i o n sur le s i te de P . E . , d a n s 4 cas sur 10 (40 % ) , des m r t a s t a s e s g a n g l i o n n a i r e s o n t 6t6 ob- j e c t i v r e s .

L ' a p p a r i t i o n d ' e m b o l s l y m p h a t i q u e s ( o b s e r v r e d a n s 7 cas su r 10 et dans t o u s l e s cas - - 4 / 4 - - a c c o m p a g n r s de m r t a s t a s e s g a n g l i o n n a i r e s ) s e m b l e le c r i t r r e h i s t o l o g i q u e f o n d a m e n t a i du g r o u p e A . C . C . I . h h a u t r i sque . A u c u n e m 6 t a s t a s e gan- g l i o n n a i r e n ' a 6t6 t r ouv6e d a n s c e r t a i n e s s6r ies de la l i t t r r a t u r e , ma i s dans les a u t r e s p u b l i c a t i o n s ,

des t aux n e t t e m e n t p lus 61ev6s de m 6 t a s t a s e s on t 6t6 e n r e g i s t r r s [2, 4, 5, 9, 12, 21, 22, 23, 24, 25, 26, 28, 30].

Les 52 p a t i e n t s p o r t e u r s d ' A . C . C . I , h fa ib le r i sque , son t e n t r r s dans le s ch6ma de su rve i l l ance

la sui te de la P . E . : 50 % d ' e n t r e eux son t suivis r r g u l i r r e m e n t d e p u i s p lus de 3 ans. A u c u n e m6ta - s tase h d i s t a n c e n ' a 6t6 o b j e c t i v 6 e p a r la r a d i o g r a - ph ie et l ' u l t r a s o n o g r a p h i e , et a u c u n e m o d i f i c a t i o n s angu ine s u g g r r a n t une m a l a d i e n r o p l a s i q u e 6volu- t ive.

Le t aux d ' a d r n o m e s m r t a c h r o n e s est r e l a t i v e - m e n t 61ev6 d a n s n o t r e s r r i e ; si l ' on exc lu t 16 pa t i en t s d o n t la s u r v e i l l a n c e 6 ta i t i n su f f i san te , dans 11 cas sur 36 (30,5 % ) , des a d 6 n o m e s m r t a c h r o n e s on t 6t6 d r c o u v e r t s au cours de la p 6 r i o d e de s u r v e i l l a n c e ; 2 (5,5 % ) on t d 6 v e l o p p 6 un c a n c e r m r t a c h r o n e du c61on, r e s p e c t i v e m e n t 3 et 4 ans apr~s la P . E .

N o s r6su l t a t s c o n c o r d e n t avec ceux r a p p o r t r s dans la l i t t r r a t u r e i n t e r n a t i o n a l e au cours des dix de rn i~ re s a n n r e s , m o n t r a n t q u ' a u c u n e m 6 t a s t a s e d i s t ance n ' a v a i t 6t6 o b s e r v r e au cours d ' u n e p r r i o d e d ' e n v i r o n 3 ans .

D a n s la p r r s e n t e s6r ie , a u c u n e r r c i d i v e au n iveau du s i te de r r s e c t i o n n ' a 6t6 d 6 m o n t r 6 e p a r l ' e n d o s c o p i e .

Les r r s u l t a t s o b s e r v 6 s dans le g r o u p e d ' A . C . C . I . f a ib le r i sque c o n f i r m e n t la v a l e u r du s c h r m a

t h r r a p e u t i q u e a c t u e l l e m e n t a d o p t r , a lo rs que chez les p a t i e n t s h h a u t r i sque , s ' i m p o s e une r66va lua - t ion p lus s t r i c te e t h p lus c o u r t t e r m e .

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140 Volume 17 - N ~ 3 - 1987 Acta Endoscopica

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21. LANGER J.C., COHEN Z., TAYLOR B.R., STAF- FORD S., J E E J E E B H O L Y K.N., CULLEN J.B. - - Ma- nagement of patients with polyps containing malignancy removed by colonoscopic polypectomy. Dis. Colon Rectum, 1984, 27, 6-9.

22. KODAIRA S., TERAMOTO T., ONO S. - - Lymph node metastase from carcinomas developing in pedunculated and semipeduncalutad colorectal adenomas. Aust. N Z J. Surg., 1981, 51, 429-433.

23, M.V. - - When is endoscopic polypectomy adequate the- rapy for colonic polyps containing invasive carcinoma ? Gastroenterology, 1986, 91, 419-427.

24. COLACCHIO T.A., FORDE K.A., SCANTLEBURY V.P. - - Endoscopic polypectomy : inadequate treatment for invasive colorectal carcinoma. Ann. Surg., 1981, 194, 704-707.

25. COUTSOFTIDES T., SIVAK M.V., BENJAMIN S.P., JAGELMAN D. - - Colonoscopy and the management of polyps containing invasive carcinoma. Ann. Surg., 1978, 188, 638-641.

26. MUTO T., KAMINA J., SWADA T. et al. - - Colo- noscopic polypectomy in diagnosis and treatment of early carcinoma of the large intestine. Dis. Colon Rectum, 1980, 23, 68-75.

27. LABGER J.C., COHEN Z., TAYLOR B.R., STAF- FORD S., JEEJEEBHOLY K.N., CULLEN J.B. - - Ma- nagement of patients with polyps containing malignancy removed by colonoscopic polypectomy. Dis. Colon Rectum, 1984, 27, 6-9.

28. WILCOX J.M., ANDERSON P.B., COLACCHIO T.A. - - Early invasive carcinoma in colonic polyps. Cancer, 1986, 57, 160-171.

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30. COOPER H.S. - - Surgical pathology of endoscopically removed malignant polyps of the colon and rectum. Am. J. Surg. Pathol., 1983, 7, 613-622.

In the last 15 years it has been demonstrated that endoscopic polypectomy (E.P.) of the large bowel can guarantee : radical excision of the polyp, accu- rate histological diagnosis, assessment of dysplasia, removal of a neoplastic lesion, interruption of the adenoma-carcinoma sequence [1, 2, 3, 4, 5, 6].

In fact, the majority of colorectal carcinomas arise in adenomas [2, 7, 8, 9].

During the last 12 years about 3 600 polyps have been removed by colonoscopic polypectomy in 1 396 patients : excluding polypectomies performed for diagnostic purposes or treatment of residual colonic segments in cases of familial polyposis, about 80 % of the endoscopically removed polyps showed to be single or multiple sporadic adenomas. Nowadays technical problems of E.P. have been almost completely solved ; definite limits of the technique, however, should always be kept in mind in order to guarantee a radical endoscopic intervention. Besides factors limiting the use of the proce- dure, such as insufficient cleansing of the bowel or inadequate endoscopic equipment, deformation of the bowel, morphology, site, size, number of polyps should be considered limits of E.P., which have to be assessed thoroughly before each polypectomy [10].

To date two questions still need further answers : - - definition o f follow-up protocols ; - - assessment o f the therapeutic policy in cases

of adenomas containing invasive carcinoma (A.C.I.C.).

Scheduling and managing a follow-up program is sometimes difficult, due to organizational problems,

compliance o f patients, difficulties in following an increasing number of patients, even with computer facilities.

In our experience only 30 % of patients come to regular follow-up examinations: the rate of new adenomas is approximately 11% of cases.

In patients having 2-3 adenomas removed by E.P. this rate raises to 18 %, while in multiple sporadic polyposis cases to 24 % [11]. In the future it will be necessary to clearly define exact parameters which can codify a follow-up regimen: after the diagnostic assessment of a ,, clean ~ colon from polypoid growths, criteria based on age o f the patient, family history, histological type of removed polyps, number o f adenomas, site, size, morphology, degree o f dysplasia of each adenoma should allow to identify a group bearing higher risk o f metachronous adenomas and cancer (age over 40, multiple adenomas removed) versus a lower risk group (age below 40, single adenoma removed).

The former cases should have closer re-examinations, probably every 2 years, while for the latter follow-up examinations might be delayed, probably every 4 years [11, 12, 13].

The problem of adenomas containing invasive carcinoma (A.C.LC.), which are the majority o f early cancers of the large bowel - - according to W.H.O. criteria [24] --, has been systematically studied in order to define the right therapeutic policy, which should be determined by the assessment of metastatic risk. The adenoma containing invasive carcinoma is an adenoma in which there is morphologic evidence of carcinoma invading


through the muscularis mucosae into the submucosa [9, 14, 151.

An adenoma with carcinoma may metastasize via the blood or the lymphatics.

Since a possible hematogenous spread cannot be controlled, the risk of lymph node metastases should determine the therapeutic approach in these patients, E.P. versus major surgical resection.

Different factors, among which the most impor- tant are vascular invasion, tumour size and degree of differentiation, influence the rate of node metastases : the incidence of metastases increases with tumour size and anaplasia [3, 15, 16, 17, 18].

Neoplastic emboli in lymphatic vessel or veins increase the metastatic risk [15].

Adenomas with invasive carcinoma therefore, can be divided into low and high metastases risk group (table I) [2, 5, 8, 15, 16, 19] on the basis of morphological parameters.

TABLE I

HISTOLOGIC PARAMETERS OF ADENOMA WITH INVASIVE CARCINOMA

Low-risk High-risk

1. Adenocarcinoma and mucinous adenocarcinoma well differentiated or moderately differentiated.

1. Adenocarcinoma and mucinous adenocarcinoma poorly differentiated.

2. Signet-ring cell carcinoma.

3. Undifferentiated carcinoma.

4. Adenocarcinoma well or moderately differentiated with focus of 1-2-3.

5. Lymphatic or vascular permeation.

Resection margin should be in healthy tissue.

High risk patients should be subjected to major surgery ; low risk cases do not need further treatment and should enter a follow-up protocol.

Our experience can help in assessing the value of E.P. alone in low risk patients compared to major surgery in high risk patients.

MATERIAL AND METHODS

Out of 2295 adenomas of the large bowel removed by E.P. 69 adenomas containing invasive carcinoma were found in 69 patients (3 %).

A.C.I.C. in familial polyposis, A.C.1.C. in patients with synchronous carcinoma, piecemeal polypectomies, doubtful invasive carcinoma were excluded from the study.

Out of 69 patients, 17 were operated on : 5 cases were excluded from the study for inadequate assess-

ment of morphological parameters ; two patients were submitted to major surgery even if histological parameters of their endoscopically resected adenomas indicated low metastatic risk.

10 patients had surgery because of histological diagnosis of high risk A.C.I .C.

52 low risk patients were treated only by E.P. and entered a special follow-up protocol.

The follow-up protocol of low risk patients includes [4, 5] :

- - a t time of diagnosis: physical examination, chest X-ray, liver sonography, liver function tests, complete blood count (CBC), ESR, CEA ;

- - w i t h i n six months : double contrast barium enema and total colonoscopy ;

- -annually : total colonoscopy and~or double contrast barium enema, chest X-ray, hepatic sonography, liver function tests, CBC, ESR, CEA.

The high risk cases after surgical treatment are controlled as all patients operated on for colorectal cancer [20].

RESULTS

The patients bearing high risk A.C.I.C. treated by surgical resection after E.P. had a mean age of 58.9 years (range: 47-69 years); the male-female ratio was 3:2 ; the colonic site mostly involved the sigmoid colon.

Morphology of high risk A.C.I.C. was 50 % sessile, 50 % pedunculated. The mean diameter was 1.9 cm (range : 1-3 cm), the histological type of the adenoma was tubular in 8 out of 10 cases, tubulo- villous in 2. According to W.H.O. histological parameters [14] the invasive carcinoma was graded as moderately differentiated in 7 cases, poorly differentiated in 3 cases.

In 7 cases vascular invasion was found.

The E.P. resection margin was in healthy tissue in 6 cases ; contained carcinomatous tissue in 2 cases. The invasive carcinoma was close to coagula- tire necrosis of the resection margin in 2 cases.

In all surgical specimens the area of the previous E.P. was identified ; in no cases adenomatous or carcinomatous tissue was found, the 2 patients with involved resection margin included.

In these two cases the carcinomatous tissue theoretically left over on the colonic wall was pre- sumably destroyed by the coagulation current during E.P.

In one case a small extramural vessel was in- vaded.

The number of pericolic lymph nodes varied according to the extent o f resection.

In 4 patients (40 %) lymph node metastases were found (1 out of 26 nodes ; 1 out of 31 ; 1 out of

142 V o l u m e 1 7 - N ~ 3 - 1 9 8 7 A c t a E n d o s c o p i c a

13 ; 2 out of 4 respectively). One patient died from pulmonary embolism 4 days after operation ; one patient 1 year after surgery from liver cirrhosis.

In 5 out of the remaining 8 patients the follow-up period exceeds 3 years.

In 3 cases synchronous colonic adenomas were found ; 3 cases developed metachronous adenomas. No distant metastases have been found by sonography and X-ray examination so far.

In the 2 low risk patients operated on, no local or distant disease was found at operation.

The prominent clinico-pathological features of 52 low risk A.C.I .C. treated only by E.P. are the following : the mean age was 66.5 years (range: 38-91 years), the male-female ratio 2,2:1 ; the colonic site mostly involved the sigmoid colon ; the mean diameter was 22 cm (range 0.5-4 cm) ; 80 % of polyps were pedunculated.

Synchronous adenomas were found in 22 patients (44.9 %), for a total number of 48 adenomas, varying from 1 to 9 for each patient ; 50 % of cases (26 out of 52) have been followed up for more than 3 years (up to 5 years in 3 cases, 7 years in 2).

11 patients developed one or more metachronous adenomas in the follow-up period (total = 24 adenomas), 2 patients developed only hyperplastic polyps ; 2 cases had metachronous carcinomas (one in the caecum, 3 years E.P. of A.C.I.C. of the sigmoid colon ; the second in the rectum, 4 years after E.P. of A. C.I.C. of the sigmoid colon). One patient died from pancreatic cancer after 5 years.

In no case distant metastases have been so far evidenced by X-ray and ultra-sound examinations.

DISCUSSION

In our series of colonoscopic polypectomies 3 % of adenomas showed invasive carcinoma.

This figure is in agreement with literature reports in the last ten years, varying from 1.9 % to 9.4 % [1, 2, 5, 8, 13, 15, 21, 22, 23, 24, 25, 26, 27, 28, 29].

The assessment of the risk of actual lymph node metastases should determine the therapeutic

approach of patients affected by A.C.I .C. Poorly differentiated carcinoma, vascular invasion, involve- ment of the resection margin [3, 15, 16, 17, 18] are histological parameters of high risk A.C.I.C.

Some authors also stress the morphology as a high risk parameter [19, 28, 30].

In our series high risk A.C.I .C. are 50 % sessile, 50 % pedunculated : lymph node metastases have been found in 2 sessile and 2 pedunculated A.C.LC.

The high risk patients have been operated on: while residual adenomatous or carcinomatous tissue has been found in the site of the previous E.P., in 4 cases out of 10 (40 %) lymph node metastases have been found.

The occurence of lymphatic emboli (observed in 7 cases out of 10 and in all cases - - 4/4 - - with node metastases) seem to be the main histological parameter to define a high risk A. C.1. C. No lymph node metastases have been found in some series, in other papers even higher metastatic rates are reported [2, 4, 5, 9, 12, 21, 22, 23, 24, 25, 26, 28, 30].

The 52 patients bearing low risk A.C.L C., after E.P. entered the surveillance protocol : 50 % of them are actually being followed up for more than 3 years. Neither distant metastases have been so far evidenced by X-ray and sonography, nor blood tests changes suggesting active neoplastic disease.

The rate of metachronous adenomas is quite high in our series. Excluding 16 patients whose follow- up is insufficient, in 11 cases out of 36 (30.5 %) metachronous adenomas have been found during the follow-up period ; 2 patients (5.5 %) developed a metachronous carcinoma of the large bowel 3 and 4 years respectively after E.P.

These results agree with the international series reported in the last ten years, in which no case of distant metastasis has been found after a mean follow-up period of about 3 years. In our series no recurrence in the site of the previous E.P. has been endoscopically found.

The observed results in low risk A.C.I.C. treatment confirm the value of the actual therapeutic policy, while in high risk patients the need for a complete careful pathological evaluation has to be stressed.


Adénomes bénins et adénomes dégénérés du côlon. Expérience de 12 ans de polypectomie...

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