EVIDENCE FOR A MULTIFOCAL ORIGIN OF PAPILLARY SEROUS CARCINOMA OF THEPERITONEUM

Histopathological evidence suggests that papillary serous carcinoma of the peritoneum (PSCP) may be multifocal in origin. Utilizing a PCR ba sed method to detect tandem repeat polymorphisms in formalin fixed tis sue, loss of heterozygosity at eight loci on chromosomes 1, 3, 4, and 17 was studied in sir cases of PSCP. Loss of heterozygosity was assess ed at between 5 and 11 tumor sites/patient. Allelic losses at 4 loci ( 1q32-qter, 3p14.3-21.1, 17q12, 17q21.3-23) were noted. Three cases dem onstrated a different pattern of allelic loss at various anatomic site s within the same patient. In an additional case, a mutation of the p5 3 gene, detected by quantitative PCR followed by single-strand conform ation polymorphism analysis, was detected in only 2 of 5 tumor sites. The pattern of allelic loss and;he mutational pattern of the p53 gene varied at tumor sites within the same patient in 4 of 6 cases of PSCP. These findings are consistent with histopathological evidence that PS CP is multifocal in origin.