moore et al-1994-australian and new zealand journal of surgery

8/16/2019 Moore Et Al-1994-Australian and New Zealand Journal of Surgery

http://slidepdf.com/reader/full/moore-et-al-1994-australian-and-new-zealand-journal-of-surgery 1/5

Aust N Z J .

Surg

1994) 64,

242-246

MANAGEMENT OF THE MALIGNANT COLORECTAL POLYP: THE

IMPORTANCEOF CLINICOPATHOLOGICALCORRELATION

JAMES

W.

E. MOORE,ESMOND. HOFFMANN*ND ROBERT OW L ND^

Colorectal Surgical Uni t, Royal Adelaide Hospital and tDepartment

of

Patholo gy, Institute

of

Medical and

Veterinary Science, Adelaide, South Australia, Australia

The results of management of colorectal adenomas removed endoscopically and found to contain invasive cancer seen in a

single institution over a 10 year period are presented. Clinical data were obtained retrospectively from patient case notes

and all specimens were reviewed by one pathologist. Fifty-four patients with malignant polyps were studied after exclusion

of others with polypoid carcinomas, epithelial misplacement and cases managed by primary segmental resection.

Of

the

various considered predictors of adverse outcome, only histologically incomplete excision proved significant. However,

when excision was considered macroscopically complete there was no significant association between incomplete

histological excision and adverse outcome. Consideration should be given to conservative management of such cases.

Key words: colonoscopy, colorectal carcinoma, colorectal polyp, polypectomy.

INTRODUCTION

The introduction of colonoscopic polypectomy in 1969I

revolutionized the managem ent of colorectal polyps and

has become the accepted practice in cases with lesions

proximal to the distal rectum. There is continued debate

regarding management of the endoscopically removed

polyp that con tains invasive carcin oma , despite almost 2

decades of discussion in the literature.*-14 t is clear tha t

there has been a significant shift towards conservative

managem ent and yet doub t still exists over the indications

for completion resection. This study presents the 10 year

experience of one Australian institution in the manage-

ment of malignant colorectal polyps, to determine the

prognostic significance of previously described clinical

and histopathological indicator s of ad verse outcom e after

treatment by polypectomy alone.

METHODS

A

record of all colorectal polyps containing invasive

malignancy seen at the Institute of Medical and Veteri-

nary Science

IMVS)

rom January 1982 to April 1992

was obtained by review of histopathology reports coded

by the System ized Nomenclatureof Medicine (SNOMED)

number. Only polyps removed by colonoscopic snare

excision were included. Invasive malignancy was defined

as invasion by malignant cells through the muscularis

mucosae. Cases of carcinoma in situ, intramucosal car-

cinoma and epithelial misplacement (pseudocarcinoma-

tous invasion 6.17 were excluded. Cases in which there

was no adeno mato us component in the mucosa adjac ent

Correspondence:J.

Moore,

Colorectal Surgical Unit, Royal Adelaide

Hospital, Adelaide. SA

SOOO

Australia.

Accepted for publication

30

September

1993

to the invasive tumour were termed polypoid carcinomas

and were excluded. Patient case notes were reviewed and

data regarding age, sex and date of polypectomy were

obtained . The site of the po lyp within the colon was taken

from the procedure report, and its size and morphology

(sessile

vs

pedunculated) were determined from the

procedure report or from the gross description

of

the

pathology specimen,

or

both. If the patient proceeded to

a completion resection (i.e. segme ntal colectomy, anterior

resection or abdo mino perinea l resection af ter polypec-

tomy), the pattern of residu al disease was recorded (none,

bowel wall, nodal, distal or a combination of these).

Follow up was ob tained by review of case notes, and by

general practitioner and patient interview. This was re-

corded as total and disease-free follow up in m onths post-

polypectomy. Disease-free status was determined by a

combination of clinical and endoscopic criteria, at last

review. If recurrence had occurred, the pattern and timing

of recurrence (local, regional or distal) was recorded.

Mortality was classified as cancer related or unrelated.

Patients were also assign ed to one of two groups:

(1) Adverse outcom e, where either recurrence occurred

after polypectomy alone or when residual or metastatic

disease was found at com pletion resection.

(2) Favourable outcom e, where no recurrence had been

documented after endoscopic polypectomy alone

or

when

completion resection revealed no evidence of residual

malignant disease (implying that polypectomy alone

would have produced a favourable outcome).

All pathology specimens were reviewed by a single

pathologist (R. Rowland). Details regarding the type of

polyp involved (tubular, comprising greater than 2/3

tubular architecture; villous, greater than 2/3 villous

architecture; and tubulovillous, neither of these) were

recorded. The carcinoma was graded as well, moderately

or poorly differentiated according to previously describ ed



MANAGEMENT OF MALIGNANT

COLORECTAL

OLYP

243

riter ria. ̂ * ̂

The depth of invasion was recorded according

to the method described by Haggitt (Table

l).’

The

margin of clearance of invasive malignancy was meas-

ured on both lateral and deep margins in m illimetre s and

correlated with the endoscopic assessment

of

macro-

scopic clearance of the lesion. The presence or absence

of vessel invasion (defined as tumour within endothelial

lined spaces) was recorded but no attempt was m ade to

differentiate between lym phatic and venous invasion.

RESULTS

One hundred and twenty-nine pathology reports desc rib-

ing adenomatous polyps containing a focus of invasive

carcinoma were obtained after review of the records of

the IMVS. Thirty-two patients who underwent primary

resection were excluded. O ther exclusions were patients

with prior or synchronous bowel cancer (six cases),

polypoid carcinoma with no associated adenoma (five

cases), incomplete medical records

1

1

cases) and those

with seve re dysplasia

10

cases). An additional

1 1

cases

were reclassified after pathological review as having

mucosal misplaceme nt” and excluded. This left a study

group of

54

patients who had colorectal polyps with

invasive carcinoma . The mean age of the grou p was 66.7

years. The mean size of pedunculated polyps was

18.6

mm

(range

10-30)

and

21.3

mm (range

15-120)

for sessile

lesions. Median follow up was

34.5

months (range

4-1

10;

mean

39.5)

with two patients lost to follow up. Overall

70 of patients had follow up of greater than

24

months.

There was one cancer-related death and four patients

died of other causes at 5,

23, 24

and

62

months post-

Table 1.

Haggitt classification of depth of invasion

Level 1

Level

2

Level

3

Level 4

Invasive tumour (through muscularis mucosae)

confined to head

of

polyp

Invasive tumour to the junction

of

head and stalk

(i.e.

to

the ‘neck’ of polyp)

Invas ive tumour into part of the stalk

of

the polyp

Invasive tumour invading beyond the stalk, into the

submucosa of the bowel wall below the polyp but

not into the muscularis propria

A

carcinoma arising in

a

pedunculated polyp may

be

classified

as

Haggitt level 1-4 depending on the level

of

invasion seen, but a

carcinoma arising in a sess ile polyp is by definition level 4 as it involves

the submucosa

of

the underlying bowel.

Table

2

Locationof polyps

polypectomy, without clinical evidence of recurrent

disease.

Tables

2

to

4

describe the association between H aggitt

level and the site, histological type and grade of polyp.

Ninety-six per cent of polyps were located distal to the

splenic flexure (Table

2).

There was no significant differ-

ence in level of invasion between polyp types (Table 3).

Although only one poorly differentiated lesion was seen,

there was no association between Haggitt level and grade

of polyp (Table4). Vascular invasion occurred in four

cases (Table 5) but no patient with vascular invasion

suffered an adverse outcome. Haggitt level 4 invasion,

polyp morphology and grade were not statisticallysignifi-

cant predictors of adverse outcome (Table 6).

Outcome after polypectomy by completeness of exci-

sion is shown in Table7. In the

49

cases where the

endoscopist assessed the excision to be complete, only

two suffered an adverse outcome, despite tumour extend-

ing to the resection margins in 10specimens. When cases

considered to be macrosco pically com pletely excised by

the endoscopist were subdivided by completeness of

histologic al excisio n, there w as no s tatistically significant

difference in outcome at last follow up (two-tailed Fisher’s

Exact test, P

=0.4).

Histologically incomplete e xcision

was a significant predictor of adverse outcome (Tables 7,

8;

two-tailed Fisher’s Exact test, P

=0.01).

However,

within the group with histologically incomplete excision,

adverse outcom e was significantly less common when the

polyp was macroscopically completely excised compared

to those in which part of the polyp remained after removal

(P=0.01).

Twenty-nine patients were managed conservatively

following polypectomy with two adverse outcomes, and

25

patients underwent completion resection with three

adverse outcomes (Table 6). The indications for comple-

tion resection were incomplete excision 14 cases), vas-

cular invasion (one case) and stalk invasion

10

cases).

Haggitt level 4 predicted three of five adverse outcomes

(sensitivity of

60

and specificity of

64 ;

Table

8).

Following conservative management, the two adverse

outcomes (cases

1, 4;

Table 6) were manifest as small

mural recurrences at the polypectomy site detected

3

and

4

months post-polypectomy, respectively. Both were

treated by segmental resection (no nodal involvement)

and are alive and well at

8

and

52

months, respectively.

Two cases with adverse outcom e after completion resec-

tion (cases

2,

5; Table6) were found to have a single

node involved by tumour, but neither case had evidence

Haggit level Ascending Transverse Descending Sigmoid Rectum Total

1

1 12 3 16

2

3 1

4

3 1

1

7

3 12

4 (pedunculated) 8 1

9

4 (sessile) 1 1 1 1

13

Total

1 1

2 31

19

54



244

MOORE ET AL..

of residual mural disease and are alive and well at 6 and

32 m onths. The third case underwent piecemeal resection

of a large sessile rectal lesion and subsequ ent completion

resection revealed no evidence of residual tumour. Multi-

ple hepatic m etastases developed at

12

months and this

patient died 15 months post-polypectomy.

Table

3. Histopathological type of polyp

Haggitt level Tubular Tubdovillou s Villous

1

9 1 6

2

3

3

1 1

4 pedunculated)

6 2

1

4 (sessile) 3

5 5

Total 3 10 3

Exact value = N S for all comparisons (Pearson Chi-squared test)

comparing polyp type by Haggitt level .

Table

4. Grade of polyps

Haggitt level Well Moderate Poor Total

1

12

4

16

2

3 1

4

3

5 7 12

4 (pedunculated) 3 5 1 9

4 (sessile) 3 10 13

Total 26 27 1 54

Table

5. Vascular invasion

Haggitt level Present Absent Total

1

1 15

16

2

4 4

3

12 12

4 (pedunculated)

2 7 9

4 (sessile)

1

12 13

Total 4 50

54

Table 6.

Details of cases with adverse outcome

DISCUSSION

Endoscopic polypectomy was introduced in

1969

by

Wolff and Shinya' and is now the preferred management

option for large bowel polyps proximal to the distal

rectum, but the management of the polyp containing

invasive malignancy remains controversial. Series reported

in the literature are often difficult to compare because

'invasive cancer' is not always clearly defined. In this

series, carcinoma was only diagnosed when there was

invasion beyond the muscularis mucosae. Cases of car-

cinoma

in situ

or intramucosal carcinoma were excluded

because of their apparent lack of metastasizing poten-

tial. Eleven adenom as initially reported as invasive

lesions were found, after review, to represent cases of

epithelial misplacement and were excluded. This high-

lights the difficulty in distinguishing misplacement from

invasive tumour.

6

It also emph asizes the need for carefu l

review of histology both in the individual patient in

whom a decision regarding resection is pending and when

assessing the published literature. By excluding patients

with polypoid carcinoma, the authors hope to avoid a

possible source of error (i.e. including cases that may not

have been suitable for endoscopic polypectomy in the

first instance).

Pathology reporting may have other influences on

published outcomes following endoscopic removal of

malignant polyps. The extent of excision, particularly of a

pedunculated lesion, can only

be

assessed by

a

combined

clinical and histopathological assessmen t, an issue often

not stressed in the literature. The endoscopist must be

sure that no residual polyp remains and that this is

conveyed to the pathologist. Otherwise, a pedunculated

polyp may

be

reported as sessile because little stalk has

been taken. Likewise, vessel invasion in the stalk of a

pedunculated polyp may be missed if only the head of

the polyp has been excised. The w ell-defined histologic

staging system of Hagg itt2 allows the stratification of

cases by depth of invasion and, when com bined with the

endoscopist's repo rt, overcomes these difficulties.

Almost all series have used similar outcome criteria to

those the present authors have used (i.e. recurrence on

follow up or residual disease on completion resection).

Wilcox has suggested that status after follow up be

reported only after 5 or preferably

10

years to overcome

the problem of late rec~rrence.'~his is a conservative

Case number and pattern of failure* Predictive

Local Nodal on M etastasis Local Nodal on outcome)

1

2

3 4

5

valuet (adverse

recurrence resection 12/12 recurrence resection

Haggitt level

1 2

3 4 4 NS

Morphology Ped Ped

Sess Sess Ped NS

Complete excision Yes No No No No P

=0.01

(histologically)

Grade

Moderate

Well Moderate Well Moderate NS

Vessel invasion No No No No No

*See text for details; tFisher's exact test;Ped. edunculated, Sess, sessile.



MANAGEMENTOF MALIGNANT COLORJXTAL POLYP 245

Table 7.

Outcome after polypectomy by com pleteness of ex -

cision assessed by combined clinical and histological assessment

Excision Excision grossly Excision grossly

complete complete* incomplete*

but margins and margins

positive? positive?

Outcome

Outcome

favourable 37

10

0

unfavourable 1 1 3

Two cases were lost

to

follow up; *Excision grossly complete/

incomplete, endoscopist’s assessment; ?Margins positive, carcinoma at

polypectomy resection margin on histology.

Table 8. Sensitivity and specificity of H aggitt level 4 invasion

for prediction of adverse outcome

Level

4

invasion Adverse outcom e Total

Present Absent

Present

Absent

Total

3 17 20

2 30 32

5

47 52

Two cases were lost to follow

up; sensitivity =60 ; specific-

ity =63.8 ;positive predictive value

=

15 .

figure as none of the recurrences in the present study

occurred later than 24 months, despite a

mean

follow up

of almost

40

months.

The series reported here is of particular interest because

it identifies the value of the end oscop ist’s assessment of

whether or not polypectomy is complete. Tumour at or

close to the margins of resection has been widely accepted

as an im portant prognostic factor predicting local residual

disease

or

nodal m etastasis following endoscopic removal

of a malignant polyp.7.’3*20 -22he present authors’ experi-

ence supports that of others,3*5*11.23ndicating that a sig-

nificant number of polyps macroscopically completely

removed but with positive histologic margins do not

suffer an adverse outcome. If the reason for offering

completion resection to patients with histolo gically posi-

tive margins

is

the risk of residual mural disease,

it

may

be reasonable to extend conservative management of

malignant polyps to include a period of observation

followed by re-endoscopy and re-biopsy after 6 weeks.

Completion resection would then be reserved for those

with residual or recurrent malignant disease. The risk of

nodal involvement has been sug gested as further reason

for resection but in this series it was low

(3.3 )

and

approaches the operative mortality for elective resection

in patients over the age of 70 year^.^^**^ The reason for

the failure to find residual or recurrent disease in many

cases with positive margins is not clear but may relate to

the destruction of tumour cells by diathermy current at

the base of the polyp, beyond the line of endoscopic

resection. The exact magnitude of this effect is poorly

documented and in this context may warrant further

study.26

The frequency of vessel invasion in malignant polyps

varies widely between series, ranging from 1.6 to

37~0.2.3.11.12.14.26 h e reason for this is unclear and cannot

be explained by differences of tumour grade

or

type of

study (polypectomy vs resectional series). The presence

of tumour w ithin endothelia l lined spaces, espec ially with

surrounding smooth muscle, may be easily recognized,

but significant difficulties exist

in

distinguishing between

the effects of tissue retraction around the tumour and

involvement of small lymphatics or veins.I4The authors

believe this is a major sou rce of potential error and cho se

to report only unequivocal vessel invasion and not distin-

guish between venous and lymphatic involvement. This

no doubt helps to acco unt for the low incidence of vessel

invasion reported.

The presence of vessel invasion is widely considered

to be of adv erse prognostic significance and is used as an

indication for completion resection. 1312*20*23 This has re-

cently been challenged

in

a study from St Mark’s Hospi-

tal, in which there was only one adverse outcome

in

61

endoscopically completely resected malignant polyps,

20 of which had venous invasion detected.14 This is in

accordance with previous work, from that institution,

demonstrating no prognostic importance of intramural

venous invasion in D ukes’ A carcino mas resected at open

surgery.21Similar findings have been reported in Dukes’

B

colorectal lesions with respect to lymphatic invasion.

Agrez et al. found no influence of either intramural or

extramural lymph vessel involvement on age adjusted

survival following re ~e cti on .~ ’ ivatvongs ef

al.

found

that vessel invasion is only

of

impo rtance when related to

depth of invasion (by Haggitt Vascular invasion

was not associated with any adverse outcome in the

present series.

The lack of significant num bers of poorly differen tiated

tumours in the present study prevents any useful assess-

ment of the impo rtance of this variable in determinin g

outcome after polypectomy There is, however, agree-

ment in the literature that poorly differentiated lesions

should undergo completion resectio n.2+8*1 ’.13*14his is de-

spite the same lack of numbers in many series, the only

exception being the series by Nivatvongs

et

al who

reported three cases with lymph node involvement in 23

poorly differentiated lesions.26

The issue of polyp size does not seem to be of

significance as a predic tor of adverse outcom e but rather

as a limiting technical factor when considering endo-

scopic management of the index polyp. The importance

of providing the pathologist with a complete ‘excision

biopsy’ rather than an una ssessable series of tissue frag-

m ents has been discussed by many a ~ t h o r s . ~ . ~ * ~ * ~ * ~his

has led to proposed guidelines for endoscopic polyp-

ectomy based on the size of the lesion, namely 35mm

for pedunculated and

15

mm for sessile lesions.14 The

practice of piecemea l polypectom y, particularly of sessile

tumours, should be discouraged. This technique entails

increased risk to the patient and prevents accura te patho-

logical assessment of the clearance and depth of invasion.



246

MOORE

ET

AL.

I t should be reserved for pa t ients whe re the

risks of

open

surgica l management are deemed prohibit ive and

no

practical alternative exists.

REFERENCES

1 Wolff WI. Shinya H. Polypectomy via the fiberoptic

colonoscope: Removal of lesions beyond reach of the

sigmoidoscope. N. Engl.

J.

Med. 1973;

288:

329-32.

2. Haggitt RC, Glotzbach RE, Soffer EE. “ruble LD.

Prognostic factors in colorectal carcinomas arising in

adenomas: Implications for lesions removed by endoscopic

polypectomy. Gastroenterology

1985;

89:

328-36.

3.

Cranley JP, Petras RE, Carey WD, Paradis K, Sivak MV.

When is endoscopic polypectomy adequate therapy for

colonic polyps containing invasive carcinoma? Gastro-

enterology

1986;

91:

419-27.

4. Fucini C, Wolff BG, Spencer RJ. An appraisal of endo-

scopic removal of malignant polyps. Mayo Clin. Proc.

5 Williams CB, Whiteway JE, Jass JR Practical aspects of

the management of malignant polyps. Endoscopy 1987; 19:

31-7.

6. Hermanek P, Gall

FP.

Early (microinvasive) colorectal

carcinoma. I n t

J. Colorect. Dis.

1986;

1:

79-84.

7. Frei JV. Endoscopic large bowel polypectomy: Adequate

treatment of som e completely removed, minimally invasive

lesions. Am.J. Surg. Patho l. 1985;

9

355-9.

8. Richards WO. W ebb

W A ,

Mom s SJ

et al.

Patient manage-

ment after endoscopic removal of the cancerous colon

adenoma.

Ann. Surg.

1987;

205:

665-72.

9. Colacchio TA, Forde KA, Scantlebury VP. Endoscopic

polypectomy Inadequate therapy for invasive colorectal

carcinoma.

Ann. Surg.

1981;

194:

704-7.

10.

Morson BC, Bussey HJR, Samoorian S. Policy of local

excision for early cancer of the colorectum.

Gut

1977;

18:

11. Coverlizza

S,

Risio M, Ferrari A Fenoglio-Preiser CM,

Rossini FP. Colorectal adenomas containing invasive car-

cinoma: Pathologic assessment of lymph node metastatic

potential.

Cancer

1989;

64:

1937-47.

12. Sugihara K. Muto T, Morioka Y. Management of patients

with invasive carcinoma removed by colonoscopic polyp-

ectomy.

Dis. Colon Rectum

1989;

32:

829-34.

13. Wilcox GM, Anderson PB, Colacchio TA. Early invasive

carcinoma in colonic polyps: A review of the literature with

1986; 61: 123-6.

1045-50.

emphasis on assessment of the risk of metastasis. Cancer

14.

Geraghty JM, Williams CB, Talbot IC. Malignant colo-

rectal polyps: Venous invasion and successful treatment

by endoscopic polypectomy. Gut 1991; 32: 774-8.

15. Rothwell DJ (Ed.).

Systemized Nomenclature

o

Medicine:

Microglossary for Surgical Pathology.

Illinois: College of

American Pathologists, 1987.

16. Greene

EL.

pithelial misplacement in adenomatou s polyps

of the colon and rectum.

Cancer

1974; 33: 206-17.

17. Muto T, Bussey HJR, Morson BC. Pseudocarcinomatous

invasion in adenomatous polyps of the colon and rectum.

J Clin. Path.

1973;

26:

25-31.

18. Jass

JR

Atkin WS, Cuzick J

et al.

The grading of rectal

cancer: Historical perspective and a multivariate analysis

of 447 cases. Histopathology 1986 10: 437-59.

19. Goh HS, Jass JR. DNA content and the adenoma carcinoma

sequence in adenomatous polyps of the colon and rectum.

J.

Clin. Path. 1986; 39: 387-92.

20. Wolff WL. Sh inya H, Cwern M , Hsu M. Cancerous colonic

polyps: ‘Hands on’

or

‘hands off’. Am. Surg.

1990

56:

21. Talbot IC, Ritchie

S,

Leighton MH, Hughes AO. Bussey

HJR, Morson BC. Spread of rectal cancer within veins.

Histologic features and clinical significance.

Am. J.

Surg.

22. Pines A, Bat L, Shemesh E et al. Invasive colorectal

adenomas: Surgery versus colonoscopic polypectomy.

J Surg. Oncol.

1990;

43:

53-5.

23. Conte CC. Welch JP, Tennant R, Forouhar F, Lundy J,

Bloom GP. Managem ent of endoscopically remov ed malig-

nant colon polyps.

J Surg. Oncol.

1987;

36:

116-21.

24. Bokey EL, Chapuis PH, Hughes WJ. Koorey SG Hinder

JM, Edwards R. Morbidity, mortality and survival follow-

ing resection for carcinoma of the rectum at Concord

Hospital. Aust. N.Z.J Surg.

1990;

6 :

253-9.

25. Corman ML. Veidenheimer MC, Coller

JA.

Colorectal

carcinoma: A decade of experience at the Lahey Clinic.

Dis . Colon Rectum

1979; 22: 477-9.

26. Nivatvongs

S,

Rojanasakul A, Reiman HM et al. The risk

of lym ph node metastasis in colorectal polyps w ith invasive

adenocarcinoma.

Dis. Colon Rectum

1991;

34:

323-8.

27. Agrez MV, Spagno lo D, Harvey J, House AK, O’Connell

D. Prognostic significance

of

lymphatic permeation in

Dukes B colorectal cancer.

Aust.

N .Z.

J. Surg.

1988;

58:

1986;

57:

160-71.

148-52.

1981; 141: 15-17.

39-42.

moore et al-1994-australian and new zealand journal of surgery

Documents