BACKGROUNDp73, a homologue of p53, has been located at chromosome 1p36-33, a region of frequently observed loss of heterozygosity in breast cancers. The objective of the present study was to investigate the function of p73 in Japanese with breast cancers.

METHODSSixty Japanese patients with breast cancer were assessed by polymerase chain reaction single strand confirmation polymorphism analysis and direct sequencing to detect the p73 allele. p73 mRNA levels were also determined in 40 out of 60 patients by reverse-transcriptional polymerase chain reaction.

RESULTSWe analyzed the entire open reading frame of the p73 gene by polymerase chain reaction single strand confirmation polymorphism and sequencing, and failed to identify any mutations of p73 in the encoding regions detected. Loss of heterozygosity of p73 was infrequent and only found in 9% of breast carcinomas. We revealed a few polymorphisms with a frequency of 13% - 29%, which had been reported previously. Down-regulation of p73 mRNA expression was observed in tumor tissues in comparison to the normal breast tissues. A significant inverse correlation was found between p73 transcripts and high histological grade, suggesting that down-regulated p73 expression could be related to poor prognosis in those patients.

CONCLUSIONOur results suggest that p73 may serve as a tumor suppressor gene and its expression plays a role in tumorigenesis in Japanese patients with breast cancer.

Breast Neoplasms ; genetics ; metabolism ; pathology ; Carcinoma ; genetics ; metabolism ; pathology ; DNA-Binding Proteins ; genetics ; Female ; Humans ; Loss of Heterozygosity ; genetics ; Middle Aged ; Nuclear Proteins ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Protein p73 ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; Tumor Suppressor Proteins ; genetics

A 70-year-old man was admitted to our institution due to aggravation of blood-sugar level control and because an abdominal CT showed dilatation of the main pancreatic duct. Upper gastrointestinal endoscopy revealed a flat elevated tumor with central ulceration in the second portion of the duodenum. Subsequent duodenoscopy for a more detailed examination showed that the tumor had originated in the minor duodenal papilla. A biopsy specimen showed moderately differentiated adenocarcinoma. Endoscopic retrograde pancreatography via the major duodenal papilla revealed a slightly dilated main pancreatic duct and obstruction of the accessory pancreatic duct. Endoscopic ultrasonography showed a hypoechoic mass in the minor duodenal papilla with retention of the muscularis propria of the duodenum. These findings suggest that the tumor existed only to a limited extent in the minor duodenal papilla, and that the tumor did not infiltrate into the pancreas. For treatment, pylorus-preserving pancreatoduodenectomy was performed, and histological findings revealed a well-differentiated adenocarcinoma that originated in the minor duodenal papilla. Primary adenocarcinoma of the minor duodenal papilla is extremely rare. Our case is the first report of primary adenocarcinoma of the minor duodenal papilla at an early stage with no infiltration into muscularis propria of the duodenum and pancreas.
Adenocarcinoma/*pathology/ultrasonography ; Aged ; Endosonography ; Humans ; Male ; Pancreatic Ducts/*pathology/ultrasonography ; Pancreatic Neoplasms/*pathology/ultrastructure