The Prognosis of Idiopathic Proctitis J. POWELL-TUCK, JEAN K.RITCHIE & J. E. LENNARD-JONES St. Mark’s Hospital, London, England
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Powell-Tuck, J., Ritchie, J. K. & Lennard-Jones, J. E. The prognosis of idiopathic proctitis. Scand. J. Gastroent. 1977, 12, 727-732. Follow-up studies of 2 groups of patients with idiopathic proctitis show that the survival rate is little affected by the disease. The cumulative probability of extension of the inflammation to the descending colon above the left iliac crest was about 5% at 5 years and 12% at 10 years. Corresponding figures for extension to the hepatic flexure were about 4% at 5 years and 6% at 10 years. The probability of radical surgical treatment was 3-5%. Key-words: Colitis; operation; proctitis; prognosis; rectum; survival
J. Powell-Tuck, M.B., M.R.C.P., St. Mark’s Hospital, London, England
In 1962, a paper from this hospital (6) outlined the natural history of idiopathic proctitis. The defects of that study were the selection introduced by including only patients referred to the medical clinic, the comparatively few patients with a short history, the relatively short period of follow-up in most cases, and the fact that the results were not analysed actuarily. In an attempt to rectify these deficiencies, a further study has been carried out of all patients with idiopathic proctitis with a history of less than six months seen at the hospital. Long term followup data have been obtained for both groups of patients, and all the results have been subjected to actuarial analysis. DEFINITION Idiopathic proctitis has been defined as an inflammatory condition of the rectal mucosa usually associated with rectal bleeding and diagnosed by sigmoidoscopy at which there is evidence of normal mucosa above the inflamed area. The sigmoidoscopic appearances have been described in detail previously. Further investigation included microbiological examination of the stools, rectal mucosal biopsy, barium enema, and serological tests when these appeared indicated. Patients with Crohn’s disease have been excluded (including one
from the earlier series who was shown subsequently to have this condition). COMPOSITION OF T H E TWO SERIES Group 1 consists of 99 patients referred to the medical clinic at St. Mark’s Hospital during the 10 years from 15 April 195 1 onwards. The length of history at the time of referral was less than six months in 30 patients, from 6 months to one year in 15, from one year to 5 years in 35, and 5 years or more in 19. Group 2 is composed of 90 patients seen in either the medical or surgical clinics during the 10 years 1 January 1962-31 December 1971. All these patients had a history of less than 6 months at their first attendance. The age and sex distribution in both groups is shown in Table I. RESULTS
Extension of the inflammation to invotve the colon This has been defined on radiological grounds or pathological examination of operation specimens. A barium enema was only carried out if clinically indicated, and the results presented here must therefore be regarded as minimal extension
on
J. Powell-Tuck, Jean K . Ritchie & J. E. Lennard-Jones
728
Table I. Age (at entry into study) and sex distribution in the two groups
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Age group (years)
Group 1
10- 19 20-29 30-39 40-49 50-59 60-69 70-79
Group 2
Male
Female
Total
Male
Female
r0ta1
2 7 10 10 2 1 0
5 14 15 23 9 I 0
7 21 25 33 11 2 0
3 17 12 8 6 6 0
6 6 5 10 7 2 2
9 23 17 18 13 8 2
32
67
99
52
38
~~
Total
~~
~
90
Table 11. Cumulative probability of extension to sigmoid colon during period of follow-up. Group 1
Year 01234567-
8910I11213141516171819202 12 22 324-
No. entering year
Incomplete year of follow-up
99 92 91 87 80 77 71 69 67 64 62 62 62 60 59 47 41 33 30 23 20 16 14 7
4 1 2 5 1 5 0
0 11 6 8 3 6 2 4 2 7 6
1
1
1
2 0 0 0 1
Corrected No. Proportion No. in with with follow-up extension extension 97 9 1.5 90 84.5 79.5 74.5 71 68.5 66 64 62 62 6 1.5 60 53.5 44 37 3 1.5 27 22 18 15 10.5 4 0.5
3 0 2 2 2 1
2 1 1
2 0 0 1 1
1 0 0 0 1
1 0
0 0 0 0
.0309
.oooo .0222 .0237 .0252 .O 134 ,0282 .O 146 .0152 ,0313
.oooo .oooo .0163 ,0167 .Ol87
.oooo .oooo .oooo .0370 .0455
Proportion without extension
Cumulative proportion without extension
.969 1 1.0000 .9778 .9763 .9748 .9866 .97 18 .9854 ,9848 .9687 1.0000 1.0000 .9837 .9833 .98 13 1.0000 1.0000 1.0000 .9630 .9545
.969 1 ,969 1 .9476 .925 1 .9018 .8897 .8646 .8520 ,8390 .8128 .8128 .8 128 .7996 .7862 .7715 .77 15 .77 15 .77 15 .7430 ,709 1
Standard deviation .017570 .022839 .027257 .03 115 1 .032997 ,036520 .038 106 ,039656 .0425 3 8
.043856 .045 104 .046594
.052907 .060324
Prognosis of Idiopathic Proctitis
729
Table 111. Cumulative probability of extension to sigmoid colon during period of follow-up. Group 2
Year
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
01-
23456789101 I-
1213-
No. entering year 90 81 77 75 71 58 53 45 35 29 21 15 8 4
Incomplete year of follow-up 6 I 1
2 I1 5 7 10
6 8 5 7 4 4
Corrected No. in follow-up 87 80.5 76.5 74 65.5 55.5 49.5 40 32 25 18.5 11.5 6 2
No. Proportion with with extension extension 3 3 1
2 2 0 1
.0345 .0373 .0131 ,0270 .0305
.oooo ,0202
0 0 0
.oooo .oooo .oooo
1
,054 1
Proportion without extension ,9655 ,9627 ,9869 .9730 .9695 1.0000 .9798 1.0000 1.0000 1.oooo
.9459
Cumulative proportion without extension .9655 ,9295 ,9113 .8925 ,8653 ,8653 .8478 .8478 .8478 .8478 .8019
Standard deviation .019567 .027760 ,02994 1 ,033873 .037923 ,040986
.059083
0 0 0
rates. All available X-rays were reviewed, and the degree of extension was categorized as follows: Extension to the sigmoid colon below the level of the left iliac crest Extension to any point between the hepatic flexure and the colon above the left iliac crest Extension to involve the hepatic flexure or more proximal colon Cumulative extension rates for Groups 1 and 2 for each of these categories were calculated actuarily, and two examples of the method are given in Tables I1 and 111. In Table XI it can be seen that the follow-up for some of the patients in Group I is now greater than 20 years. At 5 years the cumulative proportion without extension was 90.2%, at 10
years 8 1.3%, and at 20 years 70.9%. The standard deviation, calculated by the method of Greenwood as described by Cutler & Ederer ( I ) , was 3.1% at 5 years, 4.3% at 10 years, and 6.0% at 20 years. Table 111 shows a similar calculation for patients in Group 2 in which the length of follow-up is shorter. The cumulative extension rates at 5 and 10 years for the 3 categories of extension in both groups are summarized in Tables IV and V and illustrated for each year in Figures 1 and 2. Operation Five patients in Group 1 and 4 in Group 2 required radical surgical treatment for the disease.
Table IV. The cumulative probability of extension (expressed as percentage to nearest whole number) at 5 years from entry into study Group 2
Group 1
Outcome Extension to sigmoid colon Extension above left iliac crest Extension proximal to hepatic flexure
Effective number at risk
Cumulative probability
Standard deviation
Effective number at risk
Cumulative probability
Standard deviation
79.5 82.5
10 5
3 2
65.5 69
13 7
4 3
82.5
3
2
70
5
2
J. Powell-Tuck, Jean K . Ritchie & J. E. Lennard-Jones
730
Table V. The cumulative probability of extension (expressed as percentage to nearest whole number)at 10 years from entry into study Group 2
Group I
Outcome
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
~~
~
Effective number at risk
Cumulative probability
Standard deviation
Effective number at risk
64
19
4
70
12
3
25 25
72
6
3
26.5
Cumulative probability
Standard deviation
15 12
4 4
7
3
~
Extension to sigmoid colon Extension above left iliac crest Extension proximal to hepatic flexure
x 30.
Cumulative probabillty
211.
'I.
IS.
I
/--
22.
x-x-x-x
/
I&.
x-x
/'
10.
i-/
IS. IL
i'
.
12.
,I'
10.
/
I.
/
I
12.
/*
18.
Sigrnoid colon
.....
Above iliac crrst
10. C...-.C
-...
......
8.
r.*....*..'" ;
Hrpatic flexurr
6.
Owration
..""d
4.
A
6
6,
r- - -"
2.
I.
.
c-+-l
01
+ , .
.
,
.
,
,
,
,
1
4
5
6
7
8
9
10Years
I
2
3
Fig. 2. Cumulative probability ofextensionor operation. Group 2.
Table VI. The cumulative probability of operation (expressed as percentage to nearest whole number) at 5 and 10 years from entry into study Group 2
Group 1
Time At 5 years At 10 years
Effective number at risk
Cumulative probability
Standard deviation
Effective number at risk
84.5
3
75
4
2 2
Cumulative probability
Standard deviation
71
5
27.5
5
2 2
Prognosis of Idiopathic Proctitis
13 1
Table VII. Observed and expected mortality in the two groups Group 1
Group 2
Mortality
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
Expected Observed
Male
Female
Total
Male
Female
Total
4. I9 4
1.62 1
11.8 I 5
3.92 2
1.99 2
5.9 1 4
The cumulative probability of operation at 5 and 10 years in the 2 Groups is summarized in Table VI.
Survival Five patients in Group 1 and 4 patients in Group 2 are known to have died, and the cause of death is known in each case. One patient in Group 1 died from a cause related to the disease as reported previously. The other 8 deaths appeared unrelated. The expected mortality in the two groups was calculated from the Registrar General’s Life Tables No. 12 (9) using the program MYCL (5), and the results are shown in Table VI1. The observed mortality was no higher than the expected in any group. DISCUSSION The earlier study was undertaken to investigate the relationship between idiopathic proctitis and ulcerative colitis. It was concluded that the inflammation spreads proximally in at least one-tenth of the patients. The present study, with a longer follow-up of the original series and amplified by follow-up of another series all with a short history, has shown that the extension rate is unlikely to be less than one-fifth. Table I1 shows that the cumulative probability of extension to the sigmoid colon at 20 years was 29% with a standard deviation of 6%. This suggests that the true value lies between 17 and 41%. It thus appears that at least one-fifth of patients with proctitis eventually develop a recognisable colitis. Whether or not the remaining fourfifths all have the same disease without extension cannot be determined from follow-up studies. Some authors (4) have drawn a distinction between a proctitis that remains localized and the proctitis that precedes colitis by a few months. It is
not possible at present to predict possible extension by sigmoidoscopy or histological examination of mucosal biopsy specimens, though it is possible that future work will enable different types of proctitis to be recognized. The present study suggests that spread of the inflammation to involve part of the colon may occur at any time over a period of years. The extension rate of 4% observed in two other series (3, 7 ) is less than the rate calculated from the present data; comparison is difficult because of different periods of follow-up and methods of analysis. Other series (2, 8, 10)include patients with disease extending above the rectum and are thus not comparable with our results. The majority of patients with proctitis appear to have a good prognosis over many years with no extension of the disease. In this series, among the patients with extension of the disease, the cumulative probability of developing extensive colitis was 6-7% at 10 years. The likelihood of radical surgical treatment was about 5% at 10 years. The survival of a patient with idiopathic proctitis is little affected by his disease, a fact that may be important when seeking life assurance.
ACKNOWLEDGEMENT We are very grateful to Mr. I. D. Hill of the Division of Medical Computing, Medical Research Council, for carrying out the MYCL analysis of the data. REFERENCES 1. Cutler, S. J. & Ederer. F. J. Chron. Dis. 1958. 8 , 699-7 12 2. Edwards, F. C. & Truelove, S. C. Gur 1963,4, 309-
3 I5 3. Farmer, R. G . & Brown, C. H. Dis. Colon Rect. 1972. 15. 142-146
732
J. Powell-Tuck, Jean K . Ritchie & J. E. Lennard-Jones
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
4. Folley, J. H. New Engl. J. Med. 1970, 282, 13621364 5. Hill, I. D. Brit. J. Prev. Soc. Med. 1972, 26, 132134 6. Lennard-Jones,J. E., Cooper, G. W., Newell, A. G., Wilson, C. W. E. & Avery Jones, F. Gut 1962, 3, 20 1-206 7. McKechnie, J. C., Bynum, T. E., Bentlif, P. S. & Lanza, F. L. Sth. Med. J. (Bgham, Ala.) 1974,67, 1052-1056
Received 25 April 1977 Accepted 24 May 1977
8. Nugent, F. W., Veidenheimer. M. C., Zuberi, S., Garabedian, M. M. & Parikh, N. K. Amer. J. Dig. Dis. 1970, 15, 321-326 9. Registrar General’s Decennial Supplement: England and Wales 196 1. H.M. Stationery Office, London, 1968 10. Watts, J. McK., de Dombal, F. T., Watkinson, G. & Goligher, J. C. Gut 1966, 7, 16-3 1
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
Powell-Tuck, J., Ritchie, J. K. & Lennard-Jones, J. E. The prognosis of idiopathic proctitis. Scand. J. Gastroent. 1977, 12, 727-732. Follow-up studies of 2 groups of patients with idiopathic proctitis show that the survival rate is little affected by the disease. The cumulative probability of extension of the inflammation to the descending colon above the left iliac crest was about 5% at 5 years and 12% at 10 years. Corresponding figures for extension to the hepatic flexure were about 4% at 5 years and 6% at 10 years. The probability of radical surgical treatment was 3-5%. Key-words: Colitis; operation; proctitis; prognosis; rectum; survival
J. Powell-Tuck, M.B., M.R.C.P., St. Mark’s Hospital, London, England
In 1962, a paper from this hospital (6) outlined the natural history of idiopathic proctitis. The defects of that study were the selection introduced by including only patients referred to the medical clinic, the comparatively few patients with a short history, the relatively short period of follow-up in most cases, and the fact that the results were not analysed actuarily. In an attempt to rectify these deficiencies, a further study has been carried out of all patients with idiopathic proctitis with a history of less than six months seen at the hospital. Long term followup data have been obtained for both groups of patients, and all the results have been subjected to actuarial analysis. DEFINITION Idiopathic proctitis has been defined as an inflammatory condition of the rectal mucosa usually associated with rectal bleeding and diagnosed by sigmoidoscopy at which there is evidence of normal mucosa above the inflamed area. The sigmoidoscopic appearances have been described in detail previously. Further investigation included microbiological examination of the stools, rectal mucosal biopsy, barium enema, and serological tests when these appeared indicated. Patients with Crohn’s disease have been excluded (including one
from the earlier series who was shown subsequently to have this condition). COMPOSITION OF T H E TWO SERIES Group 1 consists of 99 patients referred to the medical clinic at St. Mark’s Hospital during the 10 years from 15 April 195 1 onwards. The length of history at the time of referral was less than six months in 30 patients, from 6 months to one year in 15, from one year to 5 years in 35, and 5 years or more in 19. Group 2 is composed of 90 patients seen in either the medical or surgical clinics during the 10 years 1 January 1962-31 December 1971. All these patients had a history of less than 6 months at their first attendance. The age and sex distribution in both groups is shown in Table I. RESULTS
Extension of the inflammation to invotve the colon This has been defined on radiological grounds or pathological examination of operation specimens. A barium enema was only carried out if clinically indicated, and the results presented here must therefore be regarded as minimal extension
on
J. Powell-Tuck, Jean K . Ritchie & J. E. Lennard-Jones
728
Table I. Age (at entry into study) and sex distribution in the two groups
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
Age group (years)
Group 1
10- 19 20-29 30-39 40-49 50-59 60-69 70-79
Group 2
Male
Female
Total
Male
Female
r0ta1
2 7 10 10 2 1 0
5 14 15 23 9 I 0
7 21 25 33 11 2 0
3 17 12 8 6 6 0
6 6 5 10 7 2 2
9 23 17 18 13 8 2
32
67
99
52
38
~~
Total
~~
~
90
Table 11. Cumulative probability of extension to sigmoid colon during period of follow-up. Group 1
Year 01234567-
8910I11213141516171819202 12 22 324-
No. entering year
Incomplete year of follow-up
99 92 91 87 80 77 71 69 67 64 62 62 62 60 59 47 41 33 30 23 20 16 14 7
4 1 2 5 1 5 0
0 11 6 8 3 6 2 4 2 7 6
1
1
1
2 0 0 0 1
Corrected No. Proportion No. in with with follow-up extension extension 97 9 1.5 90 84.5 79.5 74.5 71 68.5 66 64 62 62 6 1.5 60 53.5 44 37 3 1.5 27 22 18 15 10.5 4 0.5
3 0 2 2 2 1
2 1 1
2 0 0 1 1
1 0 0 0 1
1 0
0 0 0 0
.0309
.oooo .0222 .0237 .0252 .O 134 ,0282 .O 146 .0152 ,0313
.oooo .oooo .0163 ,0167 .Ol87
.oooo .oooo .oooo .0370 .0455
Proportion without extension
Cumulative proportion without extension
.969 1 1.0000 .9778 .9763 .9748 .9866 .97 18 .9854 ,9848 .9687 1.0000 1.0000 .9837 .9833 .98 13 1.0000 1.0000 1.0000 .9630 .9545
.969 1 ,969 1 .9476 .925 1 .9018 .8897 .8646 .8520 ,8390 .8128 .8128 .8 128 .7996 .7862 .7715 .77 15 .77 15 .77 15 .7430 ,709 1
Standard deviation .017570 .022839 .027257 .03 115 1 .032997 ,036520 .038 106 ,039656 .0425 3 8
.043856 .045 104 .046594
.052907 .060324
Prognosis of Idiopathic Proctitis
729
Table 111. Cumulative probability of extension to sigmoid colon during period of follow-up. Group 2
Year
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
01-
23456789101 I-
1213-
No. entering year 90 81 77 75 71 58 53 45 35 29 21 15 8 4
Incomplete year of follow-up 6 I 1
2 I1 5 7 10
6 8 5 7 4 4
Corrected No. in follow-up 87 80.5 76.5 74 65.5 55.5 49.5 40 32 25 18.5 11.5 6 2
No. Proportion with with extension extension 3 3 1
2 2 0 1
.0345 .0373 .0131 ,0270 .0305
.oooo ,0202
0 0 0
.oooo .oooo .oooo
1
,054 1
Proportion without extension ,9655 ,9627 ,9869 .9730 .9695 1.0000 .9798 1.0000 1.0000 1.oooo
.9459
Cumulative proportion without extension .9655 ,9295 ,9113 .8925 ,8653 ,8653 .8478 .8478 .8478 .8478 .8019
Standard deviation .019567 .027760 ,02994 1 ,033873 .037923 ,040986
.059083
0 0 0
rates. All available X-rays were reviewed, and the degree of extension was categorized as follows: Extension to the sigmoid colon below the level of the left iliac crest Extension to any point between the hepatic flexure and the colon above the left iliac crest Extension to involve the hepatic flexure or more proximal colon Cumulative extension rates for Groups 1 and 2 for each of these categories were calculated actuarily, and two examples of the method are given in Tables I1 and 111. In Table XI it can be seen that the follow-up for some of the patients in Group I is now greater than 20 years. At 5 years the cumulative proportion without extension was 90.2%, at 10
years 8 1.3%, and at 20 years 70.9%. The standard deviation, calculated by the method of Greenwood as described by Cutler & Ederer ( I ) , was 3.1% at 5 years, 4.3% at 10 years, and 6.0% at 20 years. Table 111 shows a similar calculation for patients in Group 2 in which the length of follow-up is shorter. The cumulative extension rates at 5 and 10 years for the 3 categories of extension in both groups are summarized in Tables IV and V and illustrated for each year in Figures 1 and 2. Operation Five patients in Group 1 and 4 in Group 2 required radical surgical treatment for the disease.
Table IV. The cumulative probability of extension (expressed as percentage to nearest whole number) at 5 years from entry into study Group 2
Group 1
Outcome Extension to sigmoid colon Extension above left iliac crest Extension proximal to hepatic flexure
Effective number at risk
Cumulative probability
Standard deviation
Effective number at risk
Cumulative probability
Standard deviation
79.5 82.5
10 5
3 2
65.5 69
13 7
4 3
82.5
3
2
70
5
2
J. Powell-Tuck, Jean K . Ritchie & J. E. Lennard-Jones
730
Table V. The cumulative probability of extension (expressed as percentage to nearest whole number)at 10 years from entry into study Group 2
Group I
Outcome
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
~~
~
Effective number at risk
Cumulative probability
Standard deviation
Effective number at risk
64
19
4
70
12
3
25 25
72
6
3
26.5
Cumulative probability
Standard deviation
15 12
4 4
7
3
~
Extension to sigmoid colon Extension above left iliac crest Extension proximal to hepatic flexure
x 30.
Cumulative probabillty
211.
'I.
IS.
I
/--
22.
x-x-x-x
/
I&.
x-x
/'
10.
i-/
IS. IL
i'
.
12.
,I'
10.
/
I.
/
I
12.
/*
18.
Sigrnoid colon
.....
Above iliac crrst
10. C...-.C
-...
......
8.
r.*....*..'" ;
Hrpatic flexurr
6.
Owration
..""d
4.
A
6
6,
r- - -"
2.
I.
.
c-+-l
01
+ , .
.
,
.
,
,
,
,
1
4
5
6
7
8
9
10Years
I
2
3
Fig. 2. Cumulative probability ofextensionor operation. Group 2.
Table VI. The cumulative probability of operation (expressed as percentage to nearest whole number) at 5 and 10 years from entry into study Group 2
Group 1
Time At 5 years At 10 years
Effective number at risk
Cumulative probability
Standard deviation
Effective number at risk
84.5
3
75
4
2 2
Cumulative probability
Standard deviation
71
5
27.5
5
2 2
Prognosis of Idiopathic Proctitis
13 1
Table VII. Observed and expected mortality in the two groups Group 1
Group 2
Mortality
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
Expected Observed
Male
Female
Total
Male
Female
Total
4. I9 4
1.62 1
11.8 I 5
3.92 2
1.99 2
5.9 1 4
The cumulative probability of operation at 5 and 10 years in the 2 Groups is summarized in Table VI.
Survival Five patients in Group 1 and 4 patients in Group 2 are known to have died, and the cause of death is known in each case. One patient in Group 1 died from a cause related to the disease as reported previously. The other 8 deaths appeared unrelated. The expected mortality in the two groups was calculated from the Registrar General’s Life Tables No. 12 (9) using the program MYCL (5), and the results are shown in Table VI1. The observed mortality was no higher than the expected in any group. DISCUSSION The earlier study was undertaken to investigate the relationship between idiopathic proctitis and ulcerative colitis. It was concluded that the inflammation spreads proximally in at least one-tenth of the patients. The present study, with a longer follow-up of the original series and amplified by follow-up of another series all with a short history, has shown that the extension rate is unlikely to be less than one-fifth. Table I1 shows that the cumulative probability of extension to the sigmoid colon at 20 years was 29% with a standard deviation of 6%. This suggests that the true value lies between 17 and 41%. It thus appears that at least one-fifth of patients with proctitis eventually develop a recognisable colitis. Whether or not the remaining fourfifths all have the same disease without extension cannot be determined from follow-up studies. Some authors (4) have drawn a distinction between a proctitis that remains localized and the proctitis that precedes colitis by a few months. It is
not possible at present to predict possible extension by sigmoidoscopy or histological examination of mucosal biopsy specimens, though it is possible that future work will enable different types of proctitis to be recognized. The present study suggests that spread of the inflammation to involve part of the colon may occur at any time over a period of years. The extension rate of 4% observed in two other series (3, 7 ) is less than the rate calculated from the present data; comparison is difficult because of different periods of follow-up and methods of analysis. Other series (2, 8, 10)include patients with disease extending above the rectum and are thus not comparable with our results. The majority of patients with proctitis appear to have a good prognosis over many years with no extension of the disease. In this series, among the patients with extension of the disease, the cumulative probability of developing extensive colitis was 6-7% at 10 years. The likelihood of radical surgical treatment was about 5% at 10 years. The survival of a patient with idiopathic proctitis is little affected by his disease, a fact that may be important when seeking life assurance.
ACKNOWLEDGEMENT We are very grateful to Mr. I. D. Hill of the Division of Medical Computing, Medical Research Council, for carrying out the MYCL analysis of the data. REFERENCES 1. Cutler, S. J. & Ederer. F. J. Chron. Dis. 1958. 8 , 699-7 12 2. Edwards, F. C. & Truelove, S. C. Gur 1963,4, 309-
3 I5 3. Farmer, R. G . & Brown, C. H. Dis. Colon Rect. 1972. 15. 142-146
732
J. Powell-Tuck, Jean K . Ritchie & J. E. Lennard-Jones
Scand J Gastroenterol Downloaded from informahealthcare.com by McMaster University on 12/12/14 For personal use only.
4. Folley, J. H. New Engl. J. Med. 1970, 282, 13621364 5. Hill, I. D. Brit. J. Prev. Soc. Med. 1972, 26, 132134 6. Lennard-Jones,J. E., Cooper, G. W., Newell, A. G., Wilson, C. W. E. & Avery Jones, F. Gut 1962, 3, 20 1-206 7. McKechnie, J. C., Bynum, T. E., Bentlif, P. S. & Lanza, F. L. Sth. Med. J. (Bgham, Ala.) 1974,67, 1052-1056
Received 25 April 1977 Accepted 24 May 1977
8. Nugent, F. W., Veidenheimer. M. C., Zuberi, S., Garabedian, M. M. & Parikh, N. K. Amer. J. Dig. Dis. 1970, 15, 321-326 9. Registrar General’s Decennial Supplement: England and Wales 196 1. H.M. Stationery Office, London, 1968 10. Watts, J. McK., de Dombal, F. T., Watkinson, G. & Goligher, J. C. Gut 1966, 7, 16-3 1
