BACKGROUND/AIMS: p53 is known to play a central role in sensing and signaling for the growth arrest and apoptosis in cells with DNA damage. Mutation of p53 is a frequent event in esophageal squamous cell carcinoma (ESCC). p16 protein binds to cyclin dependent kinase 4 (CDK4) inhibiting the ability of CDK4 to interact with cyclin D1, and stimulates the passage through the G1 phase of cell cycle. We observed the expression patterns and frequencies of p53, p16, and cyclin D1 in esophageal dysplasia and in esophageal squamous cell carcinomas. METHODS: In 15 patients of ESCC, 5 patients of esophageal dysplasia and 5 volunteers with normal esophagus, tissue specimens were taken from esophageal lesions during the operation or endoscopic examination. We used specific monoclonal antibodies for p53 protein, p16INK4 protein and cyclin D1. Immunoreactivity was scored. RESULTS: Mean age of all groups was 66 years old (range 47-93) and men to women ratio was 19:1. p53 mutation was observed in 87% (13/15) of ESCC, in 80% (4/5) of esophageal dysplasia, in 0% (0/5) of normal mucosa (p=0.001). p16 expression was seen in 40% (2/5) of esophageal dysplasia, 27% (4/15) of ESCC and 100% (5/5) of normal mucosa (p=0.016). Cyclin D1 expression was not significantly different among 20% (1/5) of esophageal dysplasia, 53% (8/15) of ESCC and 20% (1/5) of normal mucosa. Either the expression of p53 mutation or the loss of p16 occurred in 80% (4/5) of esophageal dysplasia and in 93% (14/15) of ESCC. CONCLUSIONS: The expression of p53 mutation and the loss of p16 might play a central role in the pathogenesis of esophageal squamous cell carcinoma (ESCC), and contribute to the development of precancerous lesion such as dysplasia. In addition, there is a possibility that the mutations of p53 and p16 silencing would be the early events in ESCC development.
Aged ; Carcinoma, Neuroendocrine/*diagnosis/pathology ; Chromogranin A/analysis/immunology ; Drainage ; Female ; Humans ; Immunohistochemistry ; Liver Abscess/*radiography/surgery ; Liver Neoplasms/*diagnosis/pathology ; Radiography, Abdominal ; Synaptophysin/analysis/immunology ; Tomography, X-Ray Computed

BACKGROUND/AIMS: Colorectal neuroendocrine carcinoma is a rare neoplasm exhibiting fulminant progression and having poor prognosis. The purpose of this study is to verify the clinicopathologic characteristics of colorectal neuroendocrine carcinoma. METHODS: From June 1997 to December 2004 at Asan Medical Center, ten patients were originally identified as colorectal neuroendocrine carcinoma on the basis of H&E and immunohistochemical staining (IHC). Carcinoid tumors were excluded in this study. Medical records of thirteen patients were reviewed retrospectively. RESULTS: Ten patients (0.2%) with colorectal neuroendocrine tumors were identified from 4,512 patients with colorectal cancer; ten neuroendocrine carcinomas and three adenocarcinomas with neuroendocrine differentiation. Their median age was 60 (41-83) years. The subjects consisted of six males and seven females. Nine tumors were located in the rectum, two in the sigmoid, and each one in the transverse colon and cecum, respectively. Nine of ten neuroendocrine carcinomas expressed synaptophysin, but chromogranin A were expressed in four. All patients were advanced at the time of diagnosis, with AJCC TNM staging: stage IIIB (n=2), stage IIIC (n=3), and stage IV (n=8). The median survival for ten neuroendocrine carcinomas and three adenocarcinomas with neuroendocrine differentiation were 16.4 months and 30 months, respectively. Five patients who received chemotherapy showed median survival of 32 months (stage III) and 17.5 months (stage IV), whereas other five patients without chemotherapy died with a median survival of 6.2 months. CONCLUSIONS: Colorectal neuroendocrine tumors are extremely rare showing aggressive behavior biologically, i.e fulminant early distant metastasis. Nevertheless, improved survival may be achieved by aggressive multimodality therapy.
Adenocarcinoma/pathology ; Adult ; Aged ; Aged, 80 and over ; Biopsy ; Carcinoma, Neuroendocrine/drug therapy/mortality/*pathology ; Chromogranin A/analysis/immunology ; Colorectal Neoplasms/drug therapy/mortality/*pathology ; Drug Therapy, Combination ; Female ; Humans ; Male ; Middle Aged ; Neoplasm Metastasis ; Retrospective Studies ; Sigmoid Neoplasms/drug therapy/mortality/pathology ; Synaptophysin/analysis/immunology ; Tumor Markers, Biological/analysis/immunology