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Protooncogene abnormalities in colon cancers and adenomatous polyps.

To determine the frequency and clinical significance of oncogene abnormalities in colon cancer, deoxyribonucleic acids from 45 colon carcinomas and 15 benign adenomas were hybridized with 14 different protooncogene probes. Abnormalities of oncogenes were found in 22% of cancers at the time of resection. Amplification of c-myc or c-erbB-2 and allelic deletion of c-ras-Ha or c-myb were the most frequent abnormalities. The presence of altered oncogenes did not correlate with Dukes' stage, tumor progression, or patient survival after resection. One adenoma had an allelic deletion of the c-myb oncogene which was not seen in either the normal colon or an adjacent carcinoma. These data indicate that the spectrum of altered protooncogenes in colon carcinoma is similar to that of other adenocarcinomas, and that unstable oncogenes can be found before overt malignancy develops.

Adenocarcinoma↗

Flow cytometric DNA ploidy pattern in dysplastic mucosa, and in primary and metastatic carcinomas in patients with longstanding ulcerative colitis.

Eighty-nine fresh tissue samples from flat colonic mucosa, polypoid lesions, macroscopically evident carcinomas, and metastatic carcinomas from ten patients with longstanding ulcerative colitis (greater than or equal to 8 years duration) were analysed by DNA flow cytometry and light microscopy. Of a total of ten carcinomas found in six patients, six showed DNA aneuploidy. Three patients developed metastatic carcinomas, all with aneuploid cell populations with similar DNA indices as in the primary carcinoma. Furthermore, aneuploid cell populations with similar DNA indices often occurred, both in separate mucosa samples, as well as in mucosa and carcinoma samples, from the same patient. DNA aneuploidy was found in flat mucosa in five of the six patients with carcinoma, and in one of the four patients without carcinoma (P greater than 0.1). High grade dysplasia was found in only four of the six cases with carcinoma, indicating that high grade dysplasia is insufficient as marker for malignant development. DNA aneuploidy was found in 24% of the dysplastic mucosa samples, and in 18% of the non-dysplastic mucosa samples (n.s., both with regard to high and low grade dysplasia). Since abnormal DNA ploidy pattern was not confined to dysplastic epithelium only, DNA aneuploidy in flat mucosa may constitute an additional marker in the identification of patients at increased cancer risk who could benefit from a closer surveillance.

Adult↗

Hyperplastic polyposis of the colorectum and adenocarcinoma in a 24-year-old man.

Hyperplastic polyps in the large intestine are considered common after the age of 40, devoid of neoplastic transformation capability, and have a well-defined histological picture. Nevertheless, there exists evidence that hyperplastic polyps can present with adenomatous areas, eventually leading to carcinoma. There has been a suggestion in certain cases that a transformational sequence might exist in the genesis of colorectal cancer: hyperplastic polyp-adenoma-adenocarcinoma. Adenocarcinoma resulting from a pure hyperplastic polyp has also been described. These data have generated reconsideration of the significance of hyperplastic polyps in relation to cancer. In this paper we present a 24-year-old man with adenocarcinoma of the colon who underwent a right hemicolectomy. Twenty-eight hyperplastic polyps were found in the surgical specimen. Two of these polyps had adenomatous areas. The patient died 18 months after the surgical resection.

Adenocarcinoma↗

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.

Adult↗

Screening for colon cancer.

Colorectal cancer screening reduces mortality in individuals 50 years and older. Each of the screening tests currently available has advantages and limitations, and there is no consensus as to which test or combination of tests is best. What is clear, however, is that the rates of colorectal cancer screening remain low. This review summarizes the clinical evidence supporting colorectal cancer screening in the average risk population and in high risk groups, discusses the advantages and disadvantages of the available screening tests, outlines the currently recommended guidelines for screening based on risk category, and discusses new and emerging technologies for colorectal cancer screening.

Adenoma↗

False-negative results at multi-detector row CT colonography: multivariate analysis of causes for missed lesions.

PURPOSE: To determine causes of false-negative results at multi-detector row computed tomographic (CT) colonography and determine presumptive causes with logistic regression analysis. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. The study included 394 colonic segments in 31 men and 25 women at high risk for colorectal cancer (mean age +/- standard deviation, 60.2 years +/- 9.3 for men and 56.8 years +/- 13.3 for women). Multi-detector row CT colonography and colonoscopy (reference standard) were performed in a blinded manner, and the results were compared. CT colonographic findings were interpreted in consensus by two readers using a primary two-dimensional with three-dimensional problem-solving approach. Adequacy of colonic preparation and distention was recorded. Sensitivity and specificity were obtained with 95% confidence intervals (CIs). Lesions missed at CT colonography were retrospectively reassessed to identify why they were missed, and, if the causes were not apparent, logistic regression analysis was performed to determine the presumptive causes. RESULTS: Colonic preparation and distention were optimal in 17 patients (30%) but suboptimal in 37 (66%) and poor enough to make the results nondiagnostic in two (4%). Twenty-nine of 63 lesions were missed at CT colonography. When all flat, sessile, and pedunculated lesions (n = 63) were included, sensitivities were 75% (nine of 12; 95% CI: 48%, 100%) for lesions 10 mm or larger and 79% (19 of 24; 95% CI: 65%, 93%) for those 6 mm or larger. When only sessile and pedunculated lesions (n = 60) were included, corresponding sensitivities were 100% (nine of nine; 73%, 100%) and 90% (19 of 21; 78%, 100%), respectively. All three missed lesions larger than 10 mm were flat, and all three flat lesions were missed. Two 3-mm high lesions, including one invasive adenocarcinoma, were misinterpreted as feces at blinded image review; one 1-mm high tubular adenoma with adenocarcinoma foci could not be visualized even in retrospect. Sessile or pedunculated polyps 5 mm or smaller were significantly more likely to be missed than those 6 mm or larger (adjusted odds ratio, 11.6; P = .027). CONCLUSION: Aside from inadequate bowel preparation and/or distention, flat lesions and small polyps are the two main causes for missed lesions at multi-detector row CT colonography.

Adenocarcinoma↗

Colorectal carcinoma: a radiologic and clinical review.

A profusion of imaging techniques is currently used for evaluating patients with suspected or known colorectal carcinoma. In most institutions, the combination of flexible sigmoidoscopy and a well-performed barium enema study should be retained as a more cost-effective, safe, and complete method of examination than colonoscopy. Endosonography appears to be promising for evaluating preoperatively the local extent of rectal carcinoma. CT is being challenged by MR imaging as the most sensitive modality for detecting liver metastases, but CT currently remains the technique of choice for evaluating recurrent disease and its extent. The diversity of available modalities will ensure that the radiologist remains at the forefront in the clinical investigation of colorectal carcinoma.

Barium Sulfate↗

Coexistence of multiple perifollicular fibromas and colonic polyp and cancer.

Perifollicular fibroma (PFF) is a rare cutaneous hamartoma that shows differentiation to the connective tissue sheath of the hair follicle. It may be solitary or multiple; the latter has been suggested to exhibit autosomal dominant inheritance and association with colonic polyposis. We report a 72-year-old Japanese female with multiple PFF on the face, possibly familial, who developed colon cancer in addition to colonic polyps.

Adenocarcinoma↗