Distribution of colorectal cancer in patients with and without ulcerative colitis

Cancer in inflammatory bowel disease. An evidence-based analysis and guide for physicians and patients

The risk of cancer in IBD is real and is a cause of anxiety and concern among patients and practitioners. Current modalities for detecting dysplasia in IBD are crude and insensitive and subject to observer and sampling bias. This evidence-based review confirms a significant increased risk for colorectal cancer among patients with pancolonic UC and, to a lesser extent, in patients with left-sided disease. Risk increases with longer duration of disease; early age at diagnosis; coexisting PSC; and, perhaps, a family history of colorectal cancer. Physicians must pay greater attention to the manner in which they implement surveillance colonoscopies, including paying heed to the location and number of biopsy specimens required to maximize the benefit. With respect to CD, the evidence suggests that patients with extensive colonic involvement of long duration carry a similar risk of colorectal cancer to patients with UC and should be considered candidates for surveillance colonoscopy.

Squamous cell carcinoma complicating idiopathic inflammatory bowel disease

Squamous cell carcinoma of the colon and rectum, originating proximal to the transitional zone, is a rare complication of idiopathic inflammatory bowel disease (IIBD). To date there are only 15 single case reports of such an occurrence. This carcinoma develops more commonly in females and in patients with pancolonic disease of more than 8 years' duration. The rectum is affected in two thirds of the cases. Squamous cell changes, in the vicinity of the primary adenocarcinoma, are present in 27% of cases. The carcinoma is in a pathologically advanced stage in one third of the cases. Colectomy is the main therapeutic modality. Survival following surgical resection ranged from 7 months to 21 years. We present an additional case of rectal squamous cell carcinoma (SCC) complicating chronic ulcerative colitis in a 33-year-old woman who had the disease for 15 years. Multiple biopsies of a gross lesion located 5 cm above the dendate line were consistent with invasive basaloid cell carcinoma. The patient received 5-FU, mitomycin C, and radiotherapy prior to a proctocolectomy and ileostomy. The only histopathologic finding at pathologic review of the surgical specimen was severe squamous dysplasia.

A clinicopathologic study of small flat colorectal carcinoma

BACKGROUND

Recent studies have noted that small flat carcinomas do exist in the human colon, but their clinicopathologic features have not been fully delineated.

METHODS

A clinicopathologic study of 62 flat colorectal carcinomas (FCC) and 80 polypoid colorectal carcinomas (PCC) was performed. FCC were defined for the study as colorectal adenocarcinomas confined to the mucosa or submucosa, macroscopically characterized as slightly elevated, often nearly flat, and sometimes with central shallow depressions.

RESULTS

In intramucosal and submucosal invasive carcinomas, the mean size of FCCs was significantly smaller than that of PCCs, (P < 0.001). When compared with PCCs, FCCs were found more often in the proximal colon, less frequently well differentiated, and had fewer adenomatous remnants. In submucosal invasive cases, FCCs showed more frequent deep invasion (67 versus 32%, P < 0.05) and lymphovascular permeation (41% versus 16%, P < 0.05) compared with PCCs.

CONCLUSIONS

These results suggest that FCCs are characterized by frequent deep invasion with lymphovascular permeation even when small, and that they may be more prevalent away from the rectosigmoid area.

Gastrointestinal malignancies in Crohn's disease. A 20-year experience

The relationship between gastrointestinal neoplasms and Crohn's disease is poorly defined. The purpose of this study was to characterize the features of gastrointestinal malignancies that developed in Crohn's patients. In this retrospective review the authors identified six patients with Crohn's disease who developed such lesions over a 20-year period: four patients had colorectal cancers and two had ileal malignant neoplasms. Patients averaged 52.7 years of age (range, 21 to 61 years). Three patients were men and three women. Five of the six patients had endured Crohn's disease for more than 20 years. Only two lesions were diagnosed before surgery. The colorectal lesions were predominantly right-sided and all occurred in bowel segments with active Crohn's disease. The lesions demonstrated aggressive histologic features: three of six tumors were poorly differentiated, one of the five adenocarcinomas was mucinous, and three of the colorectal cancers were Dukes' B or C lesions. Four of six patients survived five or more years. There was a single malignant carcinoid, which represents the seventh case report of a carcinoid tumor occurring in a patient with Crohn's disease. This study indicates that patients with Crohn's disease develop a wide variety of small bowel and colorectal cancers. Furthermore, it suggests that Crohn's patients with colonic disease should periodically undergo surveillance colonoscopy.