Intraperitoneal chemotherapy following neoadjuvant chemotherapy and optimal interval tumor reductive surgery for advanced ovarian cancer.

OBJECTIVES: Intraperitoneal (IP) chemotherapy following neoadjuvant chemotherapy (NACT) and interval tumor reductive surgery (TRS) for advanced ovarian cancer is feasible, however, the impact on disease outcomes remains unclear. We compare outcomes of patients treated with IP chemotherapy versus intravenous (IV) chemotherapy following NACT and interval TRS. METHODS: In this retrospective review, patients with advanced ovarian cancer were included if they received NACT followed by optimal interval TRS between 1/2004 and 4/2017. Patients were excluded if they had an ECOG PS >1, received >6 cycles of NACT or postoperative chemotherapy, and/or received bevacizumab during primary therapy. Primary outcomes were progression free survival (PFS) and overall survival (OS). RESULTS: There were 134 patients included in this study, 37 (28%) received IP and 97 (72%) received IV chemotherapy postoperatively. Patients in the IV group were older (median 66.3 vs 59.7 years, p = 0.0039) though there were no differences in BMI, race, BRCA status, stage, or histology. Median PFS was 3 months longer in the IP group (14.5 versus 11.5 months, p = 0.028) however there was no significant difference in OS. On univariate analysis, increasing number of NACT cycles (HR 1.914, 95% CI 1.024-3.497) and residual disease at completion of TRS (HR 1.541, 95% CI 1.042-2.248) were associated with decreased PFS; IP chemotherapy was associated with increased PFS (HR 0.633, 95% CI 0.414-0.944). These associations remained on multivariate analysis. Toxicity was comparable between the groups. CONCLUSIONS: IP after NACT and optimal interval TRS was associated with in improved PFS compared to IV chemotherapy without significant differences in toxicity.

Mutations of the E-cadherin gene in human gynecologic cancers.

Expression of the E-cadherin cell adhesion molecule is reduced in several types of human carcinomas, and the protein serves as an invasion suppressor in vitro. To determine if mutations of the E-cadherin gene (on chromosome 16q22) contribute to epithelial tumorigenesis, 135 carcinomas of the endometrium and ovary were examined for alterations in the E-cadherin coding region. Four mutations were identified: one somatic nonsense and one somatic missense mutation, both with retention of the wild-type alleles, and two missense mutations with somatic loss of heterozygosity in the tumour tissue. These data support the classification of E-cadherin as a human tumour suppressor gene.

Mutation of MSH3 in endometrial cancer and evidence for its functional role in heteroduplex repair.

Many human tumours have length alterations in repetitive sequence elements. Although this microsatellite instability has been attributed to mutations in four DNA mismatch repair genes in hereditary nonpolyposis colorectal cancer (HNPCC) kindreds, many sporadic tumours exhibit instability but no detectable mutations in these genes. It is therefore of interest to identify other genes that contribute to this instability. In yeast, mutations in several genes, including RTH and MSH3, cause microsatellite instability. Thus, we screened 16 endometrial carcinomas with microsatellite instability for alterations in FEN1 (the human homolog of RTH) and in MSH3 (refs 12-14). Although we found no FEN1 mutations, a frameshift mutation in MSH3 was observed in an endometrial carcinoma and in an endometrial carcinoma cell line. Extracts of the cell line were deficient in repair of DNA substrates containing mismatches or extra nucleotides. Introducing chromosome 5, encoding the MSH3 gene, into the mutant cell line increased the stability of some but not all microsatellites. Extracts of these cells repaired certain substrates containing extra nucleotides, but were deficient in repair of those containing mismatches or other extra nucleotides. A subsequent search revealed a second gene mutation in HHUA cells, a missense mutation in the MSH6 gene. Together the data suggest that the MSH3 gene encodes a product that functions in repair of some but not all pre-mutational intermediates, its mutation in tumours can result in genomic instability and, as in yeast, MSH3 and MSH6 are partially redundant for mismatch repair.

BRCA2 mutations in primary breast and ovarian cancers.

The second hereditary breast cancer gene, BRCA2, was recently isolated. Germline mutations of this gene predispose carriers to breast cancer, and, to a lesser extent, ovarian cancer. Loss of heterozygosity (LOH) at the BRCA2 locus has been observed in 30-40% of sporadic breast and ovarian tumours, implying that BRCA2 may act as a tumour suppressor gene in a proportion of sporadic cases. To define the role of BRCA2 in sporadic breast and ovarian cancer, we screened the entire gene for mutations using a combination of techniques in 70 primary breast carcinomas and in 55 primary epithelial ovarian carcinomas. Our analysis revealed alterations in 2/70 breast tumours and none of the ovarian carcinomas. One alteration found in the breast cancers was a 2-basepair (bp) deletion (4710delAG) which was subsequently shown to be a germline mutation, the other was a somatic missense mutation (Asp3095Glu) of unknown significance. Our results suggest that BRCA2 is a very infrequent target for somatic inactivation in breast and ovarian carcinomas, similar to the results obtained for BRCA1.

Role of common genetic variants in ovarian cancer susceptibility and outcome: progress to date from the Ovarian Cancer Association Consortium (OCAC).

In this article, we review the current knowledge of the inherited genetics of epithelial ovarian cancer (EOC) susceptibility and clinical outcome. We focus on recent developments in identifying low-penetrance susceptibility genes and the role of the Ovarian Cancer Association Consortium (OCAC) in these discoveries. The OCAC was established to facilitate large-scale replication analyses for reported genetic associations for EOC. Since its inception, the OCAC has conducted both candidate gene and genome-wide association studies (GWAS); the latter has identified six established loci for EOC susceptibility, most of which showed stronger association with the serous histological subtype. Future GWAS and sequencing studies are likely to result in the discovery of additional susceptibility loci and may result in established associations with clinical outcome. Additional rare and uncommon ovarian cancer loci will likely be uncovered from high-throughput next-generation sequencing studies. Applying these novel findings to establish improved preventative and clinical intervention strategies will be one of the major challenges of future work.

MLH1 expression sensitises ovarian cancer cells to cell death mediated by XIAP inhibition.

BACKGROUND: The X-linked inhibitor of apoptosis protein (XIAP), an endogenous apoptosis suppressor, can determine the level of caspase accumulation and the resultant response to apoptosis-inducing agents such as cisplatin in epithelial ovarian cancer (EOC). In addition, the mismatch repair protein, hMLH1, has been linked to DNA damage-induced apoptosis by cisplatin by both p53-dependent and -independent mechanisms. METHODS: In this study, hMLH1 expression was correlated with clinical response to platinum drugs and survival in advanced stage (III-IV) EOC patients. We then investigated whether MLH1 loss was a determinant in anti-apoptosis response to cisplatin mediated by XIAP in isogenic and established EOC cell lines with differential p53 status. RESULTS: The percentage of cells undergoing cisplatin-induced cell killing was higher in MLH1-proficient cells than in MLH1-defective cells. In addition, the presence of wild-type hMLH1 or hMLH1 re-expression significantly increased sensitivity to 6-thioguanine, a MMR-dependent agent. Cell-death response to 6-thioguanine and cisplatin was associated with significant proteolysis of MLH1, with XIAP destabilisation and increased caspase-3 activity. The siRNA-mediated inhibition of XIAP increased MLH1 proteolysis and cell death in MLH1-proficient cells but not in MLH1-defective cells. CONCLUSION: These data suggest that XIAP inhibitors may prove to be an effective means of sensitising EOC to MLH1-dependent apoptosis.

Cell cycle genes and ovarian cancer susceptibility: a tagSNP analysis.

BACKGROUND: Dysregulation of the cell cycle is a hallmark of many cancers including ovarian cancer, a leading cause of gynaecologic cancer mortality worldwide. METHODS: We examined single nucleotide polymorphisms (SNPs) (n=288) from 39 cell cycle regulation genes, including cyclins, cyclin-dependent kinases (CDKs) and CDK inhibitors, in a two-stage study. White, non-Hispanic cases (n=829) and ovarian cancer-free controls (n=941) were genotyped using an Illumina assay. RESULTS: Eleven variants in nine genes (ABL1, CCNB2, CDKN1A, CCND3, E2F2, CDK2, E2F3, CDC2, and CDK7) were associated with risk of ovarian cancer in at least one genetic model. Seven SNPs were then assessed in four additional studies with 1689 cases and 3398 controls. Association between risk of ovarian cancer and ABL1 rs2855192 found in the original population [odds ratio, OR(BB vs AA) 2.81 (1.29-6.09), P=0.01] was also observed in a replication population, and the association remained suggestive in the combined analysis [OR(BB vs AA) 1.59 (1.08-2.34), P=0.02]. No other SNP associations remained suggestive in the replication populations. CONCLUSION: ABL1 has been implicated in multiple processes including cell division, cell adhesion and cellular stress response. These results suggest that characterization of the function of genetic variation in this gene in other ovarian cancer populations is warranted.

Validating genetic risk associations for ovarian cancer through the international Ovarian Cancer Association Consortium.

The search for genetic variants associated with ovarian cancer risk has focused on pathways including sex steroid hormones, DNA repair, and cell cycle control. The Ovarian Cancer Association Consortium (OCAC) identified 10 single-nucleotide polymorphisms (SNPs) in genes in these pathways, which had been genotyped by Consortium members and a pooled analysis of these data was conducted. Three of the 10 SNPs showed evidence of an association with ovarian cancer at P< or =0.10 in a log-additive model: rs2740574 in CYP3A4 (P=0.011), rs1805386 in LIG4 (P=0.007), and rs3218536 in XRCC2 (P=0.095). Additional genotyping in other OCAC studies was undertaken and only the variant in CYP3A4, rs2740574, continued to show an association in the replication data among homozygous carriers: OR(homozygous(hom))=2.50 (95% CI 0.54-11.57, P=0.24) with 1406 cases and 2827 controls. Overall, in the combined data the odds ratio was 2.81 among carriers of two copies of the minor allele (95% CI 1.20-6.56, P=0.017, p(het) across studies=0.42) with 1969 cases and 3491 controls. There was no association among heterozygous carriers. CYP3A4 encodes a key enzyme in oestrogen metabolism and our finding between rs2740574 and risk of ovarian cancer suggests that this pathway may be involved in ovarian carcinogenesis. Additional follow-up is warranted.

A multi-institutional evaluation of factors predictive of toxicity and efficacy of bevacizumab for recurrent ovarian cancer.

While bevacizumab has shown activity in recurrent ovarian cancer, a higher than expected incidence of bowel perforations has been reported in recent trials. We sought to determine factors associated with toxicity and tumor response in patients with relapsed ovarian cancer treated with bevacizumab. A retrospective review of patients with recurrent ovarian cancer treated with bevacizumab was undertaken. Response was determined radiographically and through CA125 measurements. Statistical analysis to determine factors associated with toxicity and response was performed. Sixty-two eligible patients were identified. The cohort had received a median of 5 prior chemotherapy regimens. Single-agent bevacizumab was administered to 12 (19%), while 50 (81%) received the drug in combination with a cytotoxic agent. Grade 3-5 toxicities occurred in 15 (24%) patients, including grade 3-4 hypertension in 4 (7%), gastrointestinal perforations in 7%, and chylous ascites in 5%. Development of chylous ascites and gastrointestinal perforations appeared to correlate with tumor response. The overall response rate was 36% (4 complete response, 17 partial response), with stable disease in 40%. A higher objective response rate was seen in the bevacizumab combination group compared to single-agent treatment (43% vs 10%) (P = 0.07). However, 29 grade 3-5 toxic episodes were seen in the combination group vs only 1 in the single-agent bevacizumab cohort (P = 0.071). We conclude that bevacizumab demonstrates promising activity in recurrent ovarian cancer. The addition of a cytotoxic agent to bevacizumab improved response rates at the cost of increased toxicity. Gastrointestinal perforations occurred in 7%. The perforations occurred in heavily pretreated patients who were responding to therapy.

Relationship between lifetime ovulatory cycles and overexpression of mutant p53 in epithelial ovarian cancer.

BACKGROUND: Several lines of evidence have suggested a relationship between a woman's number of ovulatory cycles and the development of ovarian epithelial cancer. Repair of the ovarian surface after ovulation requires cellular proliferation, and spontaneous mutations arising during the DNA synthesis that accompanies this proliferation may play a role in carcinogenesis. PURPOSE: We conducted a molecular epidemiologic study to test the hypothesis that a greater number of ovulatory cycles increases the risk of ovarian cancer by inducing proliferation-associated DNA damage. In particular, we examined the association between the lifetime number of ovulatory cycles and mutation of the p53 tumor-suppressor gene (also known as TP53) in ovarian tumors. METHODS: Case-case and case-control analyses involving participants in the Cancer and Steroid Hormone study were used to examine the association between p53 gene mutation in ovarian tumors and the lifetime number of ovulatory cycles. The women in our study were 20-54 years of age and included 197 case patients with invasive ovarian epithelial cancer and 3363 control subjects. Mutation of the p53 gene was indicated by overexpression of p53 protein (i.e., cellular accumulation of mutant p53 protein) in paraffin-embedded ovarian cancer tissue blocks; the mutant protein was detected by means of standard immunohistochemical techniques. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by employing multivariate analyses, with the use of logistic regression. Reported P values are two-sided. RESULTS: Women whose cancers overexpressed p53 protein (p53 positive) had a greater mean number of lifetime ovulatory cycles (388 +/- 77.4 cycles [mean +/- standard deviation]) than women whose cancers did not overexpress p53 protein (p53 negative) (342 +/- 119.0 cycles) (P = .0025). Furthermore, women with p53-positive tumors were more likely to have had moderate (i.e., 235-375) or high (i.e., 376-533) numbers of ovulatory cycles than women with p53-negative tumors (age-adjusted ORs = 7.0 [95% CI = 1.6-30.5] and 7.7 [95% CI = 1.4-41.2], respectively) (< or = 234 cycles was the referent category). After controlling for age, menopausal status, and nulliparity, women with p53-positive tumors were found to be significantly more likely to have had moderate or high numbers of ovulatory cycles than control subjects (ORs = 4.3 [95% CI = 1.4-13.0] and 9.1 [95% CI = 2.7-30.9], respectively); the corresponding ORs for women with p53-negative tumors compared with control subjects were 0.6 (95% CI = 0.3-1.4) and 1.3 (95% CI = 0.5-3.2), respectively. CONCLUSIONS AND IMPLICATIONS: A higher number of ovulatory cycles may be associated with increased amounts of proliferation-associated DNA damage and increased risk of developing p53-positive but not p53-negative epithelial ovarian cancer. Our results are consistent with more than one developmental pathway in the pathogenesis of this type of cancer.

Overexpression of the protein tyrosine phosphatase PTP1B in human breast cancer: association with p185c-erbB-2 protein expression.

BACKGROUND: The p185c-erbB-2 growth factor receptor protein tyrosine kinase (PTK) is overexpressed in one third of human breast cancer patients and indicates a poor prognosis in these patients. Protein tyrosine phosphatases (PTPs) may balance PTK activity as part of normal growth-regulation pathways. PTP1B is an intracellular PTP that is involved in linkage between signal transduction pathways and may interface with inappropriate PTK activity in transformed cells. PURPOSE: The aim of this study was to determine if PTP1B is overexpressed in human mammary tumors and to determine if such overexpression is associated with the overexpression of the p185c-erbB-2 receptor PTK. METHODS: Our samples were frozen sections from 29 human mammary tumors (19 pure infiltrating, two pure intraductal, and eight combined intraductal and infiltrating) and nine sections from normal breast tissue. The sections were immunohistochemically stained for PTP1B and p185c-erbB-2, and the results were analyzed statistically for association between overexpression of the two proteins. Northern blot analysis was used to assess if PTP1B overexpression was coincident with increased transcription of the PTP1B gene. RESULTS: Overexpression of the PTP1B protein was observed in 72.4% of the tumor sections compared with normal epithelium, with maximal expression occurring in 37.9% of the tumors. All of the tumor subtypes, including the pure intraductal lesions, overexpressed PTP1B. Statistical analyses demonstrated a significant association between PTP1B overexpression and breast cancer (P < .038) and between the overexpression of PTP1B and the overexpression of p185c-erbB-2 (P < .006). PTP1B messenger RNA steady-state transcription was consistently increased in tumors versus normal tissues. CONCLUSIONS: PTP1B overexpression is a common phenotypic manifestation in human breast cancers and is associated with over-expression of p185c-erbB-2. Steady-state PTP1B transcription is increased in tumor tissue. IMPLICATIONS: Further studies are needed to determine if PTP1B overexpression balances or augments PTK activity. PTP1B overexpression might also be evaluated as a clinical prognostic factor in human breast cancers.

Spectrum of mutation and frequency of allelic deletion of the p53 gene in ovarian cancer.

BACKGROUND: The p53 gene encodes a nuclear phosphoprotein present in low levels in normal human cells. The wild-type form of this protein functions to restrain inappropriate cellular proliferation. Approximately one half of human epithelial ovarian cancers have mutations in the p53 gene and overexpress the mutant protein product. Deletion of one allele of the p53 gene also frequently occurs in these cancers. PURPOSE: We sought to define the spectrum of mutations in the p53 gene in epithelial ovarian cancer with respect to both the specific codons involved and the type of mutations observed. We also examined the frequency of allelic deletion of the p53 gene in cancers containing p53 gene mutations. METHODS: Tissue samples from the epithelial ovarian cancers of 62 patients were obtained during initial laparotomy. Histologic examination was done to ensure that the experimental samples used in this study contained more than 75% cancer cells. Total RNA was extracted from these samples and separately from matched control noncancerous regions of the surgical specimen or white blood cells. The purified RNAs were reverse transcribed to generate cDNA copies of exons 4-10 of the p53 gene. Two rounds of polymerase chain reaction (PCR) were conducted to produce enough template for DNA sequence analysis of the regions of interest within the p53 gene. Dideoxy sequencing of at least two independent productions of each amplified DNA template was done to confirm the validity of the mutations found. Allelic deletions were identified by PCR and gel electrophoretic techniques to examine three polymorphisms within the p53 gene in cancer-normal DNA pairs. RESULTS: We identified 45 mutations in exons 5-8 of the p53 gene, where mutations frequently have been found in other cancer types. An additional mutation was identified in exon 4. Overall, 72% of the mutations were transitions, 24% transversions, and 4% microdeletions. Allelic deletion of the other p53 allele was seen in 67% of ovarian cancers in which a p53 mutation was present. Germ-line p53 mutations were not found in any patients whose cancers had p53 mutations. CONCLUSIONS AND IMPLICATIONS: Like p53 mutations in other types of human cancers, those in epithelial ovarian cancers are diverse and occur frequently in exons 5-8. The predominance of transition mutations suggests that p53 mutations in ovarian cancer arise because of spontaneous errors in DNA synthesis and repair rather than the direct interaction of carcinogens with DNA. These molecular data are consistent with data from epidemiologic studies that have failed to demonstrate a convincing relationship between exposure to environmental carcinogens and the development of ovarian cancer.

Clonal origin of epithelial ovarian carcinoma: analysis by loss of heterozygosity, p53 mutation, and X-chromosome inactivation.

BACKGROUND: It has been suggested that multiple sites of epithelial ovarian carcinoma on the peritoneal surface reflect polyclonal disease arising from multiple primary tumors in the peritoneal mesothelium, rather than monoclonal disease spread by metastases from one primary ovarian cancer. PURPOSE: The purpose of this study was to investigate whether ovarian cancer has a monoclonal or polyclonal origin. METHODS: DNA specimens were obtained from peripheral blood lymphocytes (normal DNA) and from multiple tumor deposits of 17 women with epithelial ovarian carcinoma: primary tumors, metastatic deposits, and ascites. The clonal origin of each tumor was determined by performing (a) analysis to detect loss of heterozygosity at five loci on chromosomes 5, 11, 13, and 17; (b) sequencing of exons 5-8 of the p53 gene; and (c) X-chromosome inactivation analysis of the phosphoglycerate kinase (PGK) gene. RESULTS: In 15 of the 17 cases analyzed, there was clear evidence of monoclonal origin. The probability that the genetic events documented in these 15 cases occurred as independent events in each tumor deposit ranged from 2.5 x 10(-1) to 3.7 x 10(-16). In two cases, the pattern of allelic deletion and p53 gene mutation was compatible with either a monoclonal origin or origin from two primary ovarian tumors. CONCLUSIONS: The results did not support the hypothesis that ovarian cancer is a multifocal, polyclonal disease. Instead, the data suggest that sporadic epithelial ovarian carcinoma has either a monoclonal or a dual primary origin. IMPLICATIONS: These findings have important implications for understanding of the natural history of ovarian cancer and for clinical strategies aimed at prevention and early detection. Further studies will be required to determine the clonal origin of familial hereditary ovarian cancer.

Elevation of multiple serum markers in patients with stage I ovarian cancer.

BACKGROUND: The high overall mortality from ovarian cancer (> 60%) relates, in part, to delays in diagnosis. When ovarian cancer is detected in stage I (International Federation of Gynecology and Obstetrics staging), up to 90% of patients can be cured. Transvaginal sonography can detect early-stage disease with great sensitivity, but it is expensive and lacks specificity. Although serum marker assays could provide a less expensive and more convenient initial screening test, the sensitivity of assays varies. Measurement of serum CA 125 in conjunction with ultrasound screening as a second-line test confers high specificity but detects only about one half of early stage ovarian carcinomas. PURPOSE: The purpose of this retrospective study was to determine whether assays of multiple serum markers would improve sensitivity by detecting a higher percentage of stage I ovarian cancers than the CA 125 assay alone. METHODS: Using immunoradiometric assays, we measured preoperative serum levels of CA 125 tumor-associated antigen, macrophage colony-stimulating factor (M-CSF), and OVX1 in 46 patients with stage I ovarian cancer of different histologies and 237 patients with benign pelvic masses. We also assayed sera from 204 apparently healthy women who had participated in a screening trial and remained free from cancer at 1 year of followup. All specimens were obtained from cryopreserved aliquots. Marker levels were considered to be elevated when levels of CA 125 were greater than 30 U/mL, M-CSF levels were greater than 3.1 ng/mL, or OVX1 levels were greater than 12.1 U/mL. RESULTS: At least one of the serum markers was elevated in 98% of patients with stage I ovarian cancer; CA 125 levels were elevated in 67%. By the same criteria, 11% of healthy individuals and 51% of patients with benign pelvic masses had at least one elevated marker value. Thus, the sensitivity of the combination of assays for the three serum markers was significantly greater than the sensitivity of the CA 125 assay (P < .0005) and specificity was moderate. CONCLUSION: A panel of these three tumor markers can identify early-stage ovarian cancer with extremely high sensitivity and moderate specificity. IMPLICATIONS: Elevation of one or more serum markers should be evaluated further as an indication for transvaginal sonography in apparently healthy women. Such a strategy might substantially reduce the expense and improve the specificity of screening compared to the use of ultrasound alone. Prospective studies with a large cohort of patients at high risk for ovarian cancer will be required to confirm these findings.

PTEN/MMAC1 mutations in endometrial cancers.

Endometrial carcinomas represent the most common gynecological cancer in the United States, yet the molecular genetic events that underlie the development of these tumors remain obscure. Chromosome 10 is implicated in the pathogenesis of endometrial carcinoma based on loss of heterozygosity (LOH), comparative genomic hybridization, and cytogenetics. Recently, a potential tumor suppressor gene, PTEN/MMAC1, with homology to dual-specificity phosphatases and to the cytoskeletal proteins tensin and auxillin was identified on chromosome 10. This gene is mutated in several types of advanced tumors that display frequent LOH on chromosome 10, most notably glioblastomas. Additionally, germ-line mutations of PTEN/MMAC1 are responsible for several familial neoplastic disorders, including Cowden disease and Bannayan-Zonana syndrome. Because this locus is included in the region of LOH in many endometrial carcinomas, we examined 70 endometrial carcinomas for alterations in PTEN/MMAC1. Somatic mutations were detected in 24 cases (34%) including 21 cases that resulted in premature truncation of the protein, 2 tumors with missense alterations in the conserved phosphatase domain, and 1 tumor with a large insertion. These data indicate that PTEN/MMAC1 is more commonly mutated than any other known gene in endometrial cancers.

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.

A deletion unit on chromosome 17q in epithelial ovarian tumors distal to the familial breast/ovarian cancer locus.

Linkage analysis in familial breast and ovarian cancer and studies of allelic deletion in sporadic ovarian tumors have suggested that chromosome 17q may be the location of a gene of importance in ovarian carcinogenesis. We have examined tumor and normal DNA samples from 120 patients with ovarian tumors for allelic deletion at 12 loci on chromosome 17q. Allelic deletion was observed in 64 cases (53%) of which 56 showed loss of heterozygosity at all loci analyzed on 17q. The pattern of allele loss at metastatic sites was consistent with loss of heterozygosity having occurred prior to metastasis. A common region of deletion, defined by 6 cases of invasive epithelial ovarian cancer and a benign serous cystadenoma, spanned 16 cM and was delimited by nm23 and GH. This region is distal to the region on chromosome 17q to which the familial breast/ovarian cancer susceptibility gene has been mapped. The results suggest that a tumor suppressor gene involved in sporadic ovarian carcinogenesis is located on the distal portion of chromosome 17q and is distinct from the gene linked to familial cases.

Tumor necrosis factor alpha as an autocrine and paracrine growth factor for ovarian cancer: monokine induction of tumor cell proliferation and tumor necrosis factor alpha expression.

Ovarian tumor cells produce macrophage colony stimulating factor, a potent chemoattractant for monocytes. Monocytes and macrophages produce tumor necrosis factor alpha (TNF-alpha) and interleukin 1 alpha or interleukin 1 beta (IL-1 beta) that can stimulate ovarian tumor cell growth. The present study has explored whether paracrine stimulation by monocyte derived cytokines might induce autocrine growth stimulation of normal and malignant ovarian epithelial cells. Endogenous expression of TNF-alpha mRNA was detected in ascites ovarian cancer cells isolated directly from patients, but not in established cultures of normal or malignant ovarian epithelial cells. When ascites tumor cells were cultured for 7 days, TNF-alpha expression ceased but could be reinduced by treatment with TNF-alpha or IL-1 beta. Ascites fluid contained concentrations of the cytokines that could mediate these effects. Similarly, treatment of normal or malignant ovarian epithelial cells with purified recombinant IL-1 beta or TNF-alpha induced transcription of TNF-alpha mRNA within 1 h. TNF-alpha protein could be detected by enzyme-linked immunosorbent assay in conditioned medium from IL-1 beta treated ovarian cancer cells. [3H]thymidine incorporation by normal or malignant ovarian epithelial cells was stimulated by a 24-h incubation with IL-1 beta or TNF-alpha. Stimulation of proliferation by IL-1 beta could be partially blocked by an antibody against TNF-alpha or by soluble TNF-alpha-receptor. Thus, TNF-alpha may function as both an autocrine and a paracrine growth factor in ovarian cancer.

Mutation of the Ki-ras protooncogene in human endometrial hyperplasia and carcinoma.

Previous studies have demonstrated that some human endometrial carcinomas contain an activating point mutation in codon 12 of the Ki-ras protooncogene. To examine the hypothesis that this mutation may occur at an earlier stage of neoplastic progression in the endometrium, we analyzed 89 samples of premalignant endometrial hyperplasia and an additional 84 samples of endometrial carcinoma for point mutations of Ki-ras codon 12. Mutations were found in all three types of endometrial hyperplasia, simple, complex, and atypical, with no clear evidence of a differential distribution in any particular type. Furthermore, the overall incidence of Ki-ras mutations in the hyperplasia specimens (16%) was similar to the incidence detected in carcinomas (18%), indicating that ras mutation may represent an early event in a subset of endometrial carcinomas. When the tissue samples were segregated as to country of origin, the frequency of this mutation was approximately 2-fold higher in hyperplasia and carcinoma samples from Japan than from the United States, where the incidence, clinicopathological characteristics, and risk factors for endometrial carcinoma differ dramatically. There was no apparent correlation, however, between ras mutation and any pathological, histological, or clinical parameter examined, except survival. The presence of a ras mutation was inversely associated with death from disease, suggesting that this molecular feature may characterize a subset of endometrial carcinomas with a good prognosis.