Allelotype of human ovarian cancer.

In order to determine which chromosome(s) carries a tumor suppressor gene(s) for human ovarian cancer, we examined loss of heterozygosity in 37 tumors with a set of polymorphic DNA markers which cover each autosomal chromosome arm partially. Frequent losses were observed in chromosomes 4p (42%), 6p (50%), 7p (43%), 8q (31%), 12p (38%), 12q (33%), 16p (33%), 16q (38%), 17p (46%), 17q (39%), and 19p (34%). In addition to these chromosomes, frequent losses of alleles on chromosomes 6q, 13q, and 19q were observed uniquely in serous and serous papillary cystadenocarcinomas; loss of heterozygosity was detected only rarely on these chromosomal arms in nonserous types of tumors. The average (0.12) of fractional allelic loss seen in mucinous cystadenocarcinoma, which usually has a better prognosis than other types, was much lower than that of other tumor phenotypes including serous cystadenocarcinoma (0.31) and clear cell carcinoma (0.20). These results suggested that (a) a large number of tumor suppressor genes might play a role in ovarian cancer, (b) losses of alleles in different chromosomal regions could account for differences in histopathological features and/or prognoses among patients, and (c) this kind of analysis can contribute to an improved understanding of tumor development and/or progression in human ovarian cancer.