Colonic epithelial dysplasia or carcinoma in a regional group of patients with ulcerative colitis of more than 15 years duration

Impact of mucosal inflammation on risk of colorectal neoplasia in patients with ulcerative colitis: a systematic review and meta-analysis

BACKGROUND AND AIMS

Long-standing ulcerative colitis is an established risk factor for colorectal neoplasia. A number of observational studies have suggested that evidence of mucosal inflammation (endoscopic or histologic) is associated with a greater risk for colorectal neoplasia than is mucosal healing. Our goal was to systematically analyze the risk of colorectal neoplasia in patients with ulcerative colitis who have ongoing mucosal inflammation to better inform surveillance strategies.

METHODS

We performed a systematic review and meta-analysis of the effect of endoscopic and/or histologic inflammation on the risk of colorectal neoplasia in cohort and case-control studies. Sensitivity analyses for study setting and case definition were performed.

RESULTS

Six studies met the inclusion criteria, incorporating outcomes in 1443 patients. No study used a single validated measure for mucosal inflammation. The pooled odds ratio for colorectal neoplasia was 3.5 (95% confidence interval [CI], 2.6-4.8; P < .001) in those with any mucosal inflammation and 2.6 (95% CI, 1.5-4.5; P = .01) in those with histologic inflammation, when compared with those with mucosal healing. The overall quality of the studies was good.

CONCLUSION

The presence of objective evidence of mucosal inflammation during follow-up in patients with ulcerative colitis is associated with a greater risk of subsequent colorectal neoplasia than in those with mucosal healing. This risk factor should be considered in guidelines on surveillance intervals for these patients.

Long-term risk of cancer in ulcerative colitis: a population-based cohort study from Copenhagen County

BACKGROUND & AIMS

Ulcerative colitis (UC) is associated with an increased risk for colorectal cancer (CRC) and possibly also increased risk for cancers outside the intestinal tract. We followed-up a population-based cohort of 1160 patients with UC diagnosed in Copenhagen County between 1962 and 1987 for up to 36 years to analyze the overall and site-specific cancer risk.

METHODS

Observed vs. expected cancers were presented as standardized morbidity ratio (SMR) with 95% exact confidence intervals (CI) calculated by using individual person-years at risk and sex- and age-specific incidence rates for the Danish background population in 1995.

RESULTS

The cohort was followed-up for a median of 19 years, or 22,290 person-years. A total of 124 malignancies were observed compared with 139.85 expected (SMR, .89; 95% CI, .74-1.07). The observed number of CRCs was almost exactly equal to expected: 13 cases vs. 12.42 (SMR, 1.05; 95% CI, .56-1.79). The cumulative probability of CRC was .4% by 10 years, 1.1% by 20 years, and 2.1% by 30 years of disease. Among men, melanoma was increased (SMR, 3.45; 95% CI, 1.38-7.10); otherwise, no increased risk for cancer could be detected. No hepatobiliary cancers and no increased risk for lymphoma or leukemia were found.

CONCLUSIONS

Neither the overall cancer risk, nor the CRC risk, were increased in this population-based cohort after a median of 19 years of follow-up evaluation. An active surgical approach in medical treatment failures and long-term use of 5-aminosalicylic acid (5-ASA) as relapse prevention may explain this remarkable result.

The risk of colorectal cancer in ulcerative colitis: a meta-analysis

BACKGROUND AND AIMS

Controversy surrounds the risk of colorectal cancer (CRC) in ulcerative colitis (UC). Many studies have investigated this risk and reported widely varying rates.

METHODS

A literature search using Medline with the explosion of references identified 194 studies. Of these, 116 met our inclusion criteria from which the number of patients and cancers detected could be extracted. Overall pooled estimates, with 95% confidence intervals (CI), of cancer prevalence and incidence were obtained using a random effects model on either the log odds or log incidence scale, as appropriate.

RESULTS

The overall prevalence of CRC in any UC patient, based on 116 studies, was estimated to be 3.7% (95% CI 3.2-4.2%). Of the 116 studies, 41 reported colitis duration. From these the overall incidence rate was 3/1000 person years duration (pyd), (95% CI 2/1000 to 4/1000). The overall incidence rate for any child was 6/1000 pyd (95% CI 3/1000 to 13/1000). Of the 41 studies, 19 reported results stratified into 10 year intervals of disease duration. For the first 10 years the incidence rate was 2/1000 pyd (95% CI 1/1000 to 2/1000), for the second decade the incidence rate was estimated to be 7/1000 pyd (95% CI 4/1000 to 12/1000), and in the third decade the incidence rate was 12/1000 pyd (95% CI 7/1000 to 19/1000). These incidence rates corresponded to cumulative probabilities of 2% by 10 years, 8% by 20 years, and 18% by 30 years. The worldwide cancer incidence rates varied geographically, being 5/1000 pyd in the USA, 4/1000 pyd in the UK, and 2/1000 pyd in Scandinavia and other countries. Over time the cancer risk has increased since 1955 but this finding was not significant (p=0.8).

CONCLUSIONS

Using new meta-analysis techniques we determined the risk of CRC in UC by decade of disease and defined the risk in pancolitics and children. We found a non-significant increase in risk over time and estimated how risk varies with geography.

Low incidence of significant dysplasia in a successful endoscopic surveillance program of patients with ulcerative colitis

BACKGROUND/AIMS

Colorectal cancer associated with ulcerative colitis may be preceded by dysplastic changes potentially detectable by repeated endoscopic examinations. The aim of this study was to evaluate the incidence, course, and risk factors for dysplasia in a prospective endoscopic study.

METHODS

One hundred fifty-four patients with ulcerative colitis for 7 or more years' duration were followed from 1976 to 1994 in an endoscopic surveillance program.

RESULTS

Five patients had 10 adenomatous polyps managed by polypectomy. Indefinite dysplasia was found in 16 patients, and none showed progressive dysplasia on follow-up. Low-grade dysplasia was detected in 10 patients; 2 had and 2 progressed to high-grade dysplasia. High-grade dysplasia was found in 7 patients; 4 were concurrent with or just preceded cancer. All 4 cases of cancer were first detected by surveillance, and 3 were successfully treated. Significant risk factors for dysplasia (all grades) and cancer included the extent of disease (P < 0.01), older age at onset of colitis (P = 0.01), and the duration of disease (P < 0.05). The adjusted risk for cancer was significantly increased (P = 0.04).

CONCLUSIONS

Indefinite dysplasia did not predict developing cancer. Low- or high-grade dysplasia was not frequent (8.5%) but was associated with progression to cancer. These can be detected and successfully treated by systematic endoscopic surveillance of patients with chronic (> or = 7 years), extensive (more than the rectosigmoid colon) ulcerative colitis.

Are we telling patients the truth about surveillance colonoscopy in ulcerative colitis?

The recommended approach to the increased risk of colorectal carcinoma in ulcerative colitis has been colonoscopic surveillance rather than prophylactic colectomy. This strategy is based on the assumption that dysplastic lesions can be detected before invasive cancer has developed. We have analysed published reports on dysplasia surveillance to find out whether this assumption is valid. Ten prospective studies (1225 patients) satisfied our criteria. Of 40 patients with dysplasia-associated mass or lesion (DALM) detected, 17 (43%) already had cancer at immediate colectomy. The risks of cancer at immediate colectomy were 42% (10 of 24 patients) for high-grade and 19% (3 of 16) for low-grade dysplasia. Of 47 patients found to have high-grade dysplasia after the initial colonoscopy, 15 (32%) had cancer. 16-29% of patients with untreated low-grade dysplasia progressed to DALM, high-grade dysplasia, or cancer. Of patients with indefinite results, 28% progressed to high-grade dysplasia and 9% to cancer, so continued surveillance is essential. The risk of progression to dysplasia was only 2.4% for patients whose initial result was negative, so surveillance could perhaps be less frequent for these patients. Immediate colectomy is essential for all patients diagnosed with high-grade or low-grade dysplasia. A diagnosis of dysplasia does not preclude the presence of invasive cancer. We believe that patients should be informed about the limitations of colonoscopic surveillance so that they can take part rationally in decision-making about their management.

Colorectal cancer risk and mortality in patients with ulcerative colitis

A regional inception cohort of 1161 ulcerative colitis (UC) patients was followed up from diagnosis to the end of 1987. The follow-up rate for death and occurrence of cancer was 99.9% (median observation time, 11.7 years; range, 0-26 years). One hundred forty-one deaths were observed, 26 caused by UC or complications thereof. No significant excess mortality was found after the first year, but in the year of diagnosis the relative risk of death was 2.4 (P < 0.001). The cumulative colectomy rate 25 years after diagnosis was 32.4%. The initial extent of disease significantly influenced the colectomy probability, being 35% in total colitis, 19% in substantial colitis, and 9% in distal colitis within the first 5 years after diagnosis. Six patients developed colorectal cancer within the observation period. Compared with the expected number of 6.6, the relative risk for patients with UC was 0.9. The calculated cumulative cancer incidence was 3.1% after 25 years (95% confidence limits, 0.0-6.8). The calculated lifetime risk (0-74 years) for development of colorectal cancer was 3.5% for UC patients compared with 3.7% for the Danish population. It is concluded that with an active approach to medical and surgical treatment, as practiced here, patients whose colons are left intact bear no significantly increased risk of colorectal malignancy.