Free DNA and carcinoembryonic antigen serum levels: an important combination for diagnosis of colorectal cancer.

Purpose: The identification of new molecular markers for the early detection of colorectal cancer has become an important objective. We compared the sensitivity and specificity of free circulating DNA with that of the more conventional carcinoembryonic antigen (CEA) and evaluated the two markers in combination.

Experimental Design: The study was carried out on 75 healthy donors and 75 colorectal cancer patients.

Mutation analysis of p53, K-ras, and BRAF genes in colorectal cancer progression.

Gene mutations in APC, K-ras, and p53 are thought to be essential events for colorectal cancer development. Recent data seem to indicate that K-ras and p53 mutations rarely co-exist in the same tumor, indicating that these alterations do not represent a synergistic evolutionary pathway. Moreover, an inverse relation between K-ras gene activation and BRAF mutations has been demonstrated, suggesting alternative pathways for colorectal cancer transformation.

Skip lesion of the cecum associated with proctitis: an atypical case of ulcerative colitis.

The authors report the clinical case of a patient who underwent total colectomy for acute ulcerative colitis. The unusual element in this case was the presence of a lesion ('skip lesion'), typical of ulcerative colitis, in the periappendiceal area of the cecum, which was discontinuous to the main site of disease located in the rectum and left colon. The presence of skip lesions, whose clinicopathological relevance is still unknown, would seem to disprove the widely held view that ulcerative colitis involves only the mucous membrane of the large intestine, with inflammatory processes of varying intensity, but without intervening normal areas.

Detection of colorectal cancer by a quantitative fluorescence determination of DNA amplification in stool.

DNA amplification of exfoliated cells in stool represents an inexpensive and rapid test, but has only 50% to 60% sensitivity. A new quantitative method, called fluorescence long DNA, was developed and validated in our laboratory on stool obtained from 86 patients with primary colorectal cancer and from 62 healthy individuals. It consists of the amplification of stool DNA with fluorescence primers and the quantification of the amplification using a standard curve.