Chromosome abnormalities in primary endometrioid ovarian carcinoma

Specific and recurrent chromosome abnormalities may occur in regions of the genome that are involved in the conversion of normal cells to those with tumorigenic potential. Ovarian cancer is the primary cause of death among patients with gynecologic malignancies. We performed cytogenetic analysis in a subgroup of epithelial ovarian tumors, the endometrioid tumors, which are histologically indistinguishable from endometrial carcinoma of the uterus. We studied 10 endometrioid tumors to determine the degree of cytogenetic similarity between these two carcinomas. Six of 10 endometrioid tumors showed a near-triploid modal number, and one had a tetraploid modal number. Eight of the 10 contained structural chromosome abnormalities, of which the most frequent were 1p-- (5 tumors), 6q-- (4 tumors), 19q+ (4 tumors), and chromosome 3 rearrangements (4 tumors). These cytogenetic results resemble those reported for papillary ovarian tumors and differ from those of endometrial carcinoma of the uterus. We conclude that despite the histologic similarities between the endometrioid and endometrial carcinomas, the genetic abnormalities in the genesis of these tumors differ significantly.

Loss of heterozygosity of chromosome 3p sequences is an infrequent event in endometrial cancer

The genetic events associated with endometrial cancer are at present poorly understood. Frequent loss of heterozygosity (LOH) in a particular chromosomal region is often indicative of the involvement of a tumor suppressor gene. Previous studies are in disagreement over the involvement of a tumor suppressor gene(s) on the short arm of chromosome 3 in endometrial tumorigenesis. A set of 75 endometrial carcinomas was examined for the presence of LOH using 10 microsatellite repeat polymorphisms which are localized to chromosome 3p. In addition, these tumors were examined for the presence of replication errors (RER). Eleven of the 64 RER-negative tumors (17.2%) displayed LOH at one or more loci on chromosome 3p. The highest frequency of LOH at a single marker was 10.8% (4/37) at the locus D3S1312. The tumors investigated did not suggest that there was any common region of deletion. There was a significant increase in the frequency of 3p LOH in high-grade versus low-grade endometrioid adenocarcinomas (P < 0.05). Our results indicate that it is unlikely that a tumor suppressor gene on the short arm of chromosome 3 plays a major role in endometrial tumorigenesis.

p53 mutation in epithelial ovarian carcinoma and borderline ovarian tumor

We have investigated a series of 19 human ovarian carcinomas and 17 borderline ovarian tumors to determine the loss of heterozygosity on chromosome 17p and possible concurrent p53 mutations. Allelic losses were assessed using restriction fragment length polymorphism study, and p53 gene mutations were detected by single strand conformation polymorphism analysis and by direct sequencing. In addition, we stained the same tumor sections immunohistochemically to detect p53 protein in tissues. Among 19 ovarian malignant tumor samples tested, we identified 17p allelic deletions in 12 (63.2%) of 19 informative cases. The p53 gene mutation was observed in 7 of 19 (36.8%) malignant ovarian tumors, and it was predominantly observed in tumors with allelic loss on 17p (six of seven tumors, 85.7%). Although 9 cases of 17 borderline ovarian tumors showed shifted bands on single strand conformation polymorphism analysis, only one case was proved to have a point mutation in direct sequencing. We also obtained six cases (31.6%) of positive immunoreactivity from 19 ovarian cancers and 3 cases (17.6%) from 17 borderline ovarian tumors. We conclude that loss or inactivation of tumor suppressor gene function by chromosome 17p allelic deletions or p53 mutations are important genetic changes in ovarian cancer.

[Familial ovarian cancer, uterine cancer]

Familial ovarian cancer is described as a familial aggregation of ovarian cancer. The disease is heterogeneous, with at least three genotypes prodisposing to distinctive hereditary syndrome, site-specific ovarian cancer, wherein familial cancer risk is restricted to ovarian carcinoma; breast/ovary carcinoma syndrome, that is ovarian carcinoma in association with carcinoma of the breast; and Lynch syndrome II, characterized by hereditary nonpolyposis colorectal cancer with proximal colonic cancer predominance, endometrial carcinoma, and ovarian carcinoma. When a familial aggregation of ovarian cancer is observed, unaffected women in the family should have periodic gynecologic examinations, including cytologic and ultrasonographic, radiologic studies and magnetic resonance imaging, in an effort to detect preinvasive ovarian cancer. Until more reliable diagnostic methods are developed, however, the physician should consider the advisability of prophylactic oophorectomy and oral contraceptives when counseling women who have several close relatives with ovarian cancer.

Diagnostic and biological determinants in undifferentiated and poorly differentiated ovarian carcinomas

Six ovarian undifferentiated carcinomas (UCs) and 19 poorly differentiated serous (14 cases) and endometrioid (5 cases) carcinomas with areas of solid diffuse carcinomas have been considered for the study. Pathological findings were analyzed in conjunction with molecular analysis concerning the structure and expression of nm23-H1 gene. Differences in the frequency of loss of heterozigosity (LOH) of this gene have been observed between the two groups, UCs displaying lower percentage of LOH (1/5) as compared to poorly differentiated tumors (17/17). The remaining 3 cases (1 UC and 2 poorly differentiated carcinomas) were homozygotes, i.e., noninformative. UCs might occur as a consequence of cellular dedifferentiation, being at the end of the differentiation spectrum of epithelial ovarian tumors. Nevertheless, this study suggests that, in a fraction of cases, UCs could represent a distinct entity not involved in the malignant progression, associated with peculiar DNA anomalies, one possibly being that of the nm23-H1 deletion. In other words, a noticeable subset of UCs, not harboring nm23-H1 alterations, may be histologically uncommitted "ab initio". Moreover, nm23-H1 LOHs could be considered early events in the ovarian carcinogenesis, because similar molecular patterns were found both in primary and metastatic sites of the same tumor.

Analysis of clonality by polymerase chain reaction for phosphoglycerate kinase-1. Heteroduplex generator

Polymerase chain reaction (PCR) amplification has been used to determine the clonal composition of tissues based on analysis of the pattern of X-chromosome inactivation, but its use has been limited by technical difficulties. This report presents an expedited method to use PCR in the analysis of clonality. The method uses gel electrophoresis of heteroduplexes formed with an artificial heteroduplex generator (HG) and PCR products from the phosphoglycerate kinase-1 (PGK-1) gene from the tissue sections. Amplification was successful in 36 of 37 cases originally diagnosed as endometrial adenocarcinoma. HG analysis of 36 cases confirmed heterozygosity in 12 cases (33.3%). PGK-1 PCR amplification product was obtained from both control and lesional tissue in 10 of the 12 heterozygous cases. Of these 10 cases, seven were shown to consist of clonal cell populations by HG analysis. Two of three cases diagnosed as well-differentiated endometrioid adenocarcinoma were found to be comprised of polyclonal populations of cells. One case produced an anomalous pattern with HG analysis and was shown to be aneuploid by fluorescence in situ hybridization (FISH) with a chromosome X alpha-satellite probe. It is concluded that HG is a useful alternative to restriction fragment length polymorphism (RFLP) analysis of X-chromosome inactivation as a marker of tissue clonality in cases in women.

Prognostic value of DNA ploidy and S-phase fraction in stage I endometrial carcinoma

Both nuclear DNA content and S-phase fraction (SPF) can be helpful in predicting prognosis in certain malignancies. We investigated in a retrospective study the prognostic significance of nuclear DNA content and SPF as measured by flow cytometry of tumor specimens from 162 women with nonpretreated surgically staged FIGO stage I endometrial cancer using clearly defined inclusion criteria. A total of 139 (86%) cases were found to be diploid, whereas 23 (14%) were aneuploid. Ploidy showed a correlation with histologic grade, estrogen as well as progesterone receptor levels, and depth of myometrial infiltration. Univariate analysis of follow-up data showed an increased relative risk (RR) for recurrence-free survival (RFS) for grade 3 tumors (RR = 2.11, ns), for age (RR = 1.04, P = 0.023) as a continuous variable, and for SPF in diploid tumors (RR = 3.10, P = 0.035). In addition, univariate analysis of overall survival revealed similar results with a slightly increased relative risk for ploidy (RR = 1.52, ns). Multivariate analysis of RFS showed age as the only independent prognostic factor. Multivariate analysis of RFS for diploid tumors showed no independently significant factor; however, age as a continuous variable with a relative risk of 1.04 and SPF with a relative risk of 2.94 were of borderline significance. Our results suggest that abnormalities of the nuclear DNA content and SPF in this homogeneous group of patients are associated with clinical and morphological prognosticators; however, ploidy is no independent prognostic factor for RFS. For diploid tumors, SPF might be a possible independent prognostic factor.

Characterization of chromosome 9 in human ovarian neoplasia identifies frequent genetic imbalance on 9q and rare alterations involving 9p, including CDKN2

We have examined 41 forms of ovarian cancer for genetic alterations on chromosome 9 using a combination of five RFLP DNA probes and 15 simple tandem repeat polymorphisms. Genetic imbalance (i.e., loss of heterozygosity, microsatellite instability, amplification) for 1 or more informative markers on chromosome 9 was observed in 66% (27 of 41) of our tumor panel. Genetic imbalance was observed on 9q in 59% (24 of 41) of tumors informative for at least one locus. In contrast, only 13% (5 of 40) of informative tumors demonstrated a genetic alteration involving 9p. Furthermore, allelic loss on 9q was more common in late stage tumors (63%, 17 of 27) and poorly differentiated tumors (75%, 15 of 20) as compared to benign and early stage tumors (30%, 3 of 10). Evaluation of 15 tumors showing limited regions of genetic imbalance has identified 2 candidate tumor suppressor regions on 9q and 1 on 9p. Interestingly, the regions defined to 9p21-p24, 9q31, and 9q32-q34 all overlap with several known disease loci. In this aspect, the potential role of the CDKN2 gene at 9p21-p22 in ovarian carcinogenesis was assessed in an extended panel of ovarian tumors, 11 human ovarian carcinoma cell lines, and 1 cervical tumor cell line. With the use of comparative multiplex PCR, homozygous deletions were detected in 16 of 115 (14%) fresh tumors and 3 of 12 cancer cell lines. For those tumors demonstrating allelic loss for markers on 9p no somatic mutations were observed in the retained allele of CDKN2, as determined by single-strand conformation polymorphism analysis, but a mutation was observed in an additional cell line. Furthermore, CDKN2 mRNA levels were similar in the 9 cancer cell lines that retain CDKN2, as compared to normal human ovarian surface epithelial cell lines. Overall, our results suggest the potential involvement of a gene or genes on chromosome 9q and de-emphasize a significant role for the CDKN2 gene on 9p in the initiation and progression of ovarian cancer.

Protein expression of p53 and Rb suppressor genes during the first passages of human endometrial adenocarcinomas heterotransplanted into nude mice

Five human endometrial adenocarcinomas were heterotransplanted into nude mice to study changes in p53 and Rb protein expression and loss of heterozygosity of these genes during the first nude mice passages. Three of five heterotransplanted tumours were established and measured. In one tumour over-expression of p53 protein was found in passage 1 and subsequently, whereas the original tumour did not over-express the protein. We concluded that the heterotransplantation, i.e. the new host environment, may lead to mutations in the p53 gene. Two tumours from patients and also during nude mice passages expressed p53 protein in two bands, which were probably the result of allele polymorphism. Both p53 and Rb protein expression were increased after growth in estradiol-treated animals. Our results suggest that several changes in the function of these suppressor genes, including mutations, occur during the first passages in nude mice. Consequently, the growth regulation of established tumours may differ from that in their original counterparts in the patients.

Alteration of the p53 tumor suppressor gene occurs independently of K-ras activation and more frequently in serous adenocarcinomas than in other common epithelial tumors of the human ovary

To clarify the role of the p53 tumor suppressor gene in the development of human ovarian epithelial tumors and to study the association of p53 alterations with K-ras activation, a series of 70 common epithelial ovarian tumors from Japanese patients was studied. These included 31 serous adenocarcinomas, 12 mucinous adenocarcinomas, 5 mucinous tumors of borderline malignancy, 13 endometrioid adenocarcinomas, and 9 clear cell carcinomas. Allelic loss, recognized at the polymorphic site in codon 72 of the p53 gene, was detected in 14 of 36 (39%) informative cases by restriction fragment length polymorphism analysis and by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR)-amplified DNA fragments. Mutations in the highly conserved regions of the p53 gene were detected by SSCP analysis of PCR-amplified fragments. Mutations were found in 22 of 70 (31%) ovarian tumors, including 1 of 5 mucinous tumors of borderline malignancy. Mutations were subsequently characterized by direct sequencing. Single missense base substitutions were detected in 13 ovarian carcinomas and in one case of mucinous tumor of borderline malignancy. Short (1-8 bp) deletions and insertions were found in 8 cases. Mutations in the p53 gene occurred more frequently in serous adenocarcinomas (14/31, 45%) than in all nonserous types of malignant epithelial tumors combined (7/34, 21%; P = 0.032). Point mutations in K-ras were identified by dot blot hybridization analysis of PCR-amplified fragments with mutation-specific oligonucleotides and by direct sequencing. The overall frequency of K-ras mutations was 19/70 (27%). K-ras mutations were found in 12 of 17 (71%) mucinous tumors (8/12 mucinous carcinomas [67%] and 4/5 mucinous tumors of borderline malignancy [80%]), and occurred more frequently than in serous carcinomas (4/31, 13%; P = 0.00009) or in all nonmucinous types of ovarian epithelial tumors combined (7/53, 13%; P = 0.00002). These data suggest that different combinations of oncogenes and/or tumor suppressor genes may be involved in the genesis and development of histologically distinct categories of common epithelial tumors of the human ovary.

Type-IV collagenase and tissue inhibitor of metalloproteinase in ovarian cancer tissues

OBJECTIVE

We examined the specific expression of gelatinase/type-IV collagenase and tissue inhibitor of metalloproteinase (TIMP) in clinical ovarian cancer tissue.

METHODS

Molecular weight-specific gelatinase/type-IV collagenase activity was examined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis in which substrate was included (zymography). The expression of TIMP mRNA was examined by Northern blot analysis.

RESULTS

Zymography revealed that in ovarian cancer the activity of a 92-kDa gelatinase/type-IV collagenase was always greater than that of a 64-kDa gelatinase/type-IV collagenase in contrast to the situation in the normal ovary. Northern blot analysis revealed no remarkable difference of TIMP mRNA expression between cancer and normal ovarian tissues.

CONCLUSIONS

These results indicate that the higher activity of the 92-kDa gelatinase/type-IV collagenase enzyme, relative to that of the 64-kDa enzyme, is involved in the malignant phenotype of ovarian cancer, while the inhibitor of these enzymes, TIMP, is distributed in a widespread fashion in the tissue, and its levels are not correlated with the malignancy.

[The factors involved in invasive ability of endometrial carcinoma cells]

The in vitro invasive ability, the expression of cell adhesion molecule E-cadherin, activity of matrix metalloproteinase (MMP) and K-ras point mutation were investigated in eight human endometrial carcinoma cell lines. 1) In vitro invasive abilities of endometrial carcinoma cell lines depend on the degree of cell differentiation and the origin of cell lines. A poorly-differentiated carcinoma cell line (NUE-1) and a cell line derived from metastatic lymph node (SNG-M) were more invasive than moderately-(HEC-1A, HEC-1BE) and well-differentiated (HEC-6, Ishikawa) cell lines. 2) Immunohistochemically, less or non-invasive cell lines expressed E-cadherin strongly, whereas a highly invasive cell line (NUE-1) expressed E-cadherin weakly. 3) When cultured on Matrigel-coated dishes, the tumor cells derived from moderately- and well-differentiated carcinoma aggregated with each other and did not invade Matrigel in the invasion assay. The aggregated cells expressed E-cadherin more strongly when cultured on Matrigel. 4) 72-kD gelatinase (MMP-2) was secreted in serum-free conditioned medium of all cell lines. In an invasive cell line (NUE-1,SNG-M), the activity of MMP-2 was stronger than in other cell lines. And the activity of 92-kDa gelatinase (MMP-9) was detected in most invasive cell line (NUE-1). 5) Point mutation of K-ras codon 12 was detected in four of eight (50%) cell lines by the PCR-RFLP method. The changes in the DNA sequence were identified, but K-ras point mutation was not correlated with in vitro invasiveness of the tumor cells.

Multivariable analysis of DNA ploidy, p53, and HER-2/neu as prognostic factors in endometrial cancer

BACKGROUND

Several molecular-genetic alterations in endometrial cancers, including aneuploidy and aberrant expression of p53 and HER-2/neu, have been associated with poor prognosis. To determine the importance of molecular-genetic factors relative to more traditional surgical-pathologic prognostic factors, a multivariable analysis was performed.

METHODS

Immunohistochemical staining for p53, HER-2/neu, estrogen receptor, progesterone receptor, and epidermal growth factor receptor was performed on frozen sections from 100 primary endometrial cancers. DNA ploidy was determined using computerized image analysis of Feulgen-stained touch preparations. In addition, information regarding surgical-pathologic features of the cancers was obtained. Univariable analysis was performed followed by multivariable analysis using Cox's proportional hazards model to identify variables predictive of poor prognosis.

RESULTS

With univariable analysis, race, histologic type, stage, grade, myometrial invasion, estrogen receptor, progesterone receptor, ploidy, p53 and HER-2/neu were predictive of the presence of persistent or recurrent disease. In the multivariable analysis, only International Federation of Gynecology and Obstetrics stage (P = 0.005), grade (P = 0.005), myometrial invasion (P = 0.024), and ploidy (P = 0.028) were significant.

CONCLUSIONS

Among molecular-genetic prognostic factors, DNA ploidy was the most strongly predictive of persistent or recurrent disease.

Microsatellite instability in endometrial carcinoma

Microsatellite instability (MI), detected as electrophoretic shifts in allele sizes of microsatellite DNA sequences, has been identified in some colorectal carcinomas. Investigators have previously attributed such microsatellite instability to replication errors (RER). The colorectal carcinomas with RER have been found to arise either sporadically or in association with the hereditary non-polyposis colorectal cancer (HNPCC) syndrome. Because endometrial carcinoma is also commonly associated with HNPCC, we studied 30 cases of endometrial carcinoma to characterize the presence of MI in these neoplasms. Seven cases (23%) showed MI. Four cases showed both Type I (large shifts) and Type II (small shifts) mutation patterns and the remaining three cases showed Type I mutations only. We conclude that MI frequently occurs in endometrial cancers and that this type of genetic alteration may be an important pathogenetic feature of this tumor type.

Cytogenetic and FISH analysis of endometrial carcinoma

Endometrial cancer is a common gynecologic tumor, yet reports of cytogenetic studies are few. We studied chromosomes from seven primary specimens of endometrial cancer. Six had abnormal chromosomes; five had a diploid-hyperdiploid modal number and one was triploid. One specimen had a normal karyotype. Chromosome 1 was frequently involved in abnormalities (five tumors) with i(1q) in two tumors, and one tumor each had der(7)t(1;7)(q12;p11) and +add (1)(p13). One additional tumor had trisomy 1 in the single cell which could be fully analyzed. Trisomy 7 was noted in two tumors, and trisomy 10 in one. Because trisomies of these chromosomes have been reported in other cases of endometrial cancer, we used fluorescent in situ hybridization (FISH) with centromere probes to determine the prevalence of trisomies 7 and 10 in these specimens. No additional tumors were found to have trisomies 7 or 10 by FISH. Our data, in combination with published literature, suggest that additional copies of 1q or portions of 1q constitute the primary change in this tumor. Extra copies of genes in this region may play an important role in tumorigenesis in endometrial carcinoma.

Observations on tumor and metastatic suppressor gene status in endometrial carcinoma with particular emphasis on p53

BACKGROUND

Genetic changes in the development of endometrial carcinoma have not been characterized, and little is known of tumor or metastatic suppressor gene status in these malignancies. The current study on endometrioid carcinoma was undertaken to examine the status of two tumor suppressor genes that frequently have been found to be altered in human malignancies (the p53 gene and the retinoblastoma [Rb] gene) and to examine the status of the candidate metastatic suppressor gene, nm23-H1.

METHODS

The status of the p53 gene was studied by immunohistochemistry of formalin-fixed paraffin-embedded biopsy samples from 72 patients with atypical endometrial hyperplasia or endometrioid carcinoma who underwent hysterectomy immediately after biopsy and from 5 patients with benign endometria. A search for loss of heterozygosity (LOH) of the nm23 gene after DNA extraction from frozen tissues and hybridization with nm23-H1 cDNA specific probe was made in 10 endometrial carcinomas. Rb gene status was evaluated by image analysis quantification of immunoreactive retinoblastoma protein in frozen sections of 10 carcinomas and 2 benign endometria.

RESULTS

p53 expression was low in all benign endometria, but high expression was found in 2 (15%) of 13 atypical hyperplasias and in 23 (39%) of 59 carcinomas. High levels of p53 expression in endometrioid carcinoma correlated with the spread of disease outside of the uterus and by logistic regression, the presence of squamous differentiation, nuclear grade, and high p53 expression in the biopsy all independently correlated with spread of disease outside of the uterus. Although 7 of the 10 carcinomas studied were informative, LOH for the nm23 gene was not seen in any, including a site of metastasis. Rb protein expression in endometrial carcinoma was similar to expression in benign endometria.

CONCLUSIONS

Although this study found no evidence of nm23-H1 gene alteration or alterations in Rb protein levels in endometrial carcinoma, high expression of p53 protein was sporadically identified in biopsy specimens of atypical hyperplasia and frequently found in endometrioid carcinomas. Determination of p53 expression in combination with the presence or absence of squamous differentiation and nuclear grade in biopsy material may help predict spread of endometrioid carcinoma outside the uterus and facilitate therapeutic planning before hysterectomy.

Activation of c-erbB-2 and prognosis in ovarian carcinoma. Comparison with histologic type, grade, and stage

BACKGROUND

Prior reports suggested that measuring c-erbB-2 activation in ovarian carcinomas might be valuable in predicting prognosis. The authors attempted to confirm these studies while specifically excluding tumors of low malignant potential.

METHODS

The clinical and pathologic significance of c-erbB-2 oncogene activation was assessed in 56 ovarian carcinomas, none of which met histologic criteria for tumor of low malignant potential.

RESULTS

By using an immunohistochemical technique previously validated in molecular studies, c-erbB-2 oncogene overexpression was identified in 10 of the 56 carcinomas but did not correlate with histologic type, histologic grade, International Federation of Gynecology and Obstetrics (FIGO) stage, or prognosis. Adverse prognostic factors included histologic type (serous carcinoma), high grade, and high stage (FIGO Stages III and IV). Grade and stage were highly correlated with each other and were more important prognostic indicators than histologic type.

CONCLUSION

Measuring c-erbB-2 activation in ovarian carcinomas may not be of practical value in predicting prognosis when tumors of low malignant potential are excluded.

Cytogenetic studies of epithelial ovarian carcinoma

We performed cytogenetic studies of 36 human epithelial ovarian carcinomas using in situ culture and robotic harvest. We obtained analyzable metaphases of all 36 tumors (100%). One or more chromosomally abnormal clones were observed in 80% of tumors. Common clonal chromosome gains (each occurring in six or more cases) included +1, +2, +3, +6, +7, +9, and +12. Common clonal chromosome losses (occurring in 12 or more cases) included -X, -4, -8, -11, -13, -15, -17, and -22. Common clonal structural abnormalities (occurring in four or more cases) involved regions 1p36, 1q32, 1q42, 3p13-->p26, 3q26-->q29, 7p22, 9q34, 11p13-p15, 17q21-->q23, 19p13.3, and 19q13.3. Trisomy 12 was noted as the sole anomaly in three of five borderline and grade 1 tumors. Two grade 2 tumors contained i(1q), -14, -15 and -22. The results suggest that the pathogenesis of borderline and low-grade tumors may differ from that of higher grade tumors. Two high-grade tumors had an apparent translocation between 17q21 and 19p13.3, two chromosome regions believed to be critical to ovarian carcinogenesis.

Genetic instability of microsatellites in endometrial carcinoma

Hereditary nonpolyposis colorectal cancer (HNPCC) is characterized by a familial predisposition to colorectal carcinoma and extracolonic cancers of the gastrointestinal, urological, and female reproductive tracts, notably the endometrium. A genetic locus for HPNCC was recently determined by linkage analysis to exist on chromosome 2p; both sporadic and HNPCC-associated colorectal carcinomas exhibit a "replication error" phenotype, characterized by instability of dinucleotide repeat sequences throughout the genome. Here, we address the hypothesis that the replication error phenotype would be evident in some fraction of sporadic endometrial carcinomas or in those associated with HNPCC. Microsatellite instability was observed in 17% of sporadic endometrial carcinomas and in 75% of those tumors associated with HNPCC. These data indicate that the HNPCC gene is also involved in heritable and somatic forms of endometrial carcinoma.