FollowUp of US

After correct diagnosis and obtaining remission maintained by correct medical therapy, a second colonoscopy within 8 years from the beginning of the symptoms, is indicated only in case of relapse not responsive to therapy [6-9]. Refractory disease can be caused by viral infection (most commonly by cytomegalovirus), primarily in patients on immuno-suppressant maintenance therapy. In this case, the endoscopist has a front-line role taking biopsies from the bottom of the ulcers, where CMV implant, during proctosigmoidoscopy.

After 8 Years from the Beginning

The main role of colonoscopy during follow-up of UC is screening and surveillance for CRC. The lifetime prevalence of CRC in patients with UC is estimated to be 3.7% and 5.4% among those with total colitis. Rates are higher in patients with longstanding disease, and the cumulative probabilities at 10, 20 and 30 years increase to 2%, 8% and 18%, respectively. Compared with age-matched members of the general population, the relative risk of cancer is 20% for extensive colitis and 4% for left-side colitis [10]. The main risk factors for CRC in patients with UC are reported in Table 2.

Table 2. Risk factors for colorectal cancer (CRC) in ulcerative colitis (UC) patients [11].

Disease standing

Anatomic extension

Positive family history for CRC

Age at onset of UC

Severe or chronic inflammation

Primary sclerosing cholangitis

Before 8 Years from the Beginning Disease Standing

Disease standing is an independent risk factor for CRC development in patients suffering from UC. There is no standard definition for the duration of UC. Although some studies define duration based on the date of radiological, endoscopic or histological diagnosis, a preferred approach is to define it in relationship to the onset of UC-like symptoms. Since the risk of CRC becomes greater than in general population after 8-10 years from disease onset [12], the Crohn's and Colitis Foundation of America (workshop: "Colon cancer in IBD: science and surveillance", Palm Harbor, Florida, March 2000recom-mends that a screening colonoscopy be performed 8-10 years after onset of symptoms attributable to UC to redefine extension and cutoff dysplasia. Then, a regular surveillance program should be carried out.

Anatomic Extension

As disease standing it is an independent risk factor for CRC, extension should be defined by both endo-scopic and histological evaluation, whichever reveals more extensive involvement, not with radiological images since cancer and dysplasia can arise in areas of the colon that show histological evidence of disease even without macroscopic abnormalities [13].

Primary Sclerosing Cholangitis

All patients with primary sclerosing cholangitis (PSC) without prior diagnoses of irritable bowel disease (IBD) should undergo a colonoscopy to determine their status. This procedure should include biopsies from normal-appearing mucosae because microscopic evidence of colitis may not be visually apparent. For patients suffering from IBD, screening and subsequent yearly surveillance should begin at the time of PSC onset.

Age of Onset

Although there is some evidence to support a higher relative risk for CRC among UC patients diagnosed at a young age [12], there is insufficient evidence to support starting screening and surveillance before 8 years of disease onset.

Positive Family History of CRC

This is an additional risk factor for development of CRC in patient with UC [14], but there is insufficient evidence to warrant a closer follow-up.

In a recent study, Rutter et al. [15] demonstrated that some endoscopic lesions were correlated to higher risk of CRC development and, on the contrary, that normal endoscopy testified a low risk of neoplasia. Mainly, pseudopolyps were correlated to higher risk of CRC development not because of direct degeneration but because they are an expression of severe and constant inflammation. Some drugs may modify risk of development of CRC; aminosalicylate use, perhaps folic acid intake and ursodeoxycholic acid in the subset of colitis patients with PSC have been suggested to be cancer chemopreventive agents [16, 17]. A screening colonoscopy must be done to rule out dysplasia or cancer after 8-10 years from the onset of the disease. The accuracy of intestinal washout is very important because, in these patients, minimal lesions can be in situ carcinoma.

The cornerstone of endoscopic surveillance in UC is dysplasia, which is defined as unequivocal neoplastic alteration of the colonic epithelium. Dysplasia represents the histological manifestation of widespread chromosomal instability caused by the effects of persistent inflammation. Most cancers in colitis are preceded by dysplasia, and approximately 75% of cases have coexisting dysplastic change elsewhere in the colon. The detection of dysplasia in colitis is used as a clinical marker of imminent or established carcinoma. During examination, multiple biopsies must be taken, even on normal mucosae, to assess extension increase of UC [18].

After screening, patients with UC must begin a regular surveillance program (Fig. 1). Patients with extensive colitis or left-side colitis who have a negative screening colonoscopy should begin surveillance within 1-2 years. After 2 negative examinations, the next surveillance colonoscopy can be performed every 3 years until UC has been present for 20 years. At that time, consideration should be given to shorten the surveillance times to 1-2 years since CRC risk increases with longer duration of colitis. Patients with PSC should undergo yearly surveillance. Patients with proctosigmoiditis, who have little or no

Onset of symptoms of UC

8-10 years

Primary sclerosing cholangitis

Screening colonoscopy

Surveillance program (colonoscopy every 1-2 years)

I and II colonoscopy negative

Colonoscopy every 3 years to the 20° year of UC

Yearly colonoscopy

increased risk of CRC compared with the general population, should be managed according to standard CRC prevention measures as defined in guidelines [11].

Screening colonoscopy must be performed during quiescent UC because the presence of severe inflammation can cause an erroneous histological differential diagnosis from dysplasia. Standard examination must include the entire colon and the collection of 4 random biopsies every 10 cm of mucosae since it has been estimated that 33 biopsies are required to provide a 90% chance of finding the highest degree of present dysplasia [19]. In UC, dysplasia on flat mucosae is distinguished by dysplasia associated to lesions or mass (DALM) because there is a significant major risk that these harbour cancer, even if a recent study showed that in 90% of patients a scrupulous colonoscopy can detect dysplastic lesions even on flat mucosae [20].

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