COLONIC CANCER IN ULCERATIVE COLITIS AND IDIOPATHIC COLONIC CANCER

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.

A comparison of multiple synchronous colorectal cancer in ulcerative colitis, familial polyposis coli, and de novo cancer

Multiple synchronous colorectal cancer (MSCC) among 1537 patients (69 with familial polyposis coli (FPC), 780 with ulcerative colitis (UC), and 685 with de novo colorectal (DNC) cancers) admitted to The Mount Sinai Hospital between 1945 and 1981 was tabulated. MSCC occurred in five of 24 cancer patients with FPC (21%), in 12 of 65 cancer patients with UC (18%), but in only 17 of 685 DNC patients (2.5%). The proportions of MSCC cases with more than two synchronous tumors were also much greater in the former two groups (UC 6/12 = 50%, FPC 3/5 = 60%) than in DNC (0/17 = 0%). Multiplicity of cancers is thus a distinguishing feature of UC and FPC. MSCC differed from solitary cancers by association with older age and more advanced stage at diagnosis in patients with FPC and by a rightward shift in anatomic distribution in all patients, especially those with FPC and UC.

Elective surgery for ulcerative colitis: colectomy in 158 patients

Chronic ulcerative colitis was treated by elective colectomy in 158 patients. Proctocolectomy and ileostomy was performed in 140 patients and colectomy and ileorectal anastomosis (CIRA) in 18 patients. The operative mortality was 2.5%, and postoperative complications, mostly infections, occurred in 38%. Within a 2-year postoperative period another 1.9% of the patients died, and late complications occurred in 18%. Colorectal carcinoma was present at the time of colectomy in 5.1% and developed some years later in another two patients primarily operated on with CIRA. Half of the cancer patients died of malignancy. Most extracolic complications, present in 25% of patients before colectomy, regressed or disappeared after operation. Half of the patients operated on with CIRA needed to have their rectum removed within a few years because of cancer or proctitis, and few of the rest had lasting relief of symptoms.

Radiological findings in carcinoma of the colon complicating chronic ulcerative colitis

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