Synchronous endometrial and ovarian carcinomas: predictors of risk and associations with survival and tumor expression profiles

Purpose

Synchronous endometrial and ovarian tumors (SEOs) are diagnosed in 10% of ovarian cancer patients. We examined predictors of SEOs, evaluated associations of SEOs with survival and characterized ovarian tumor profiles using immunohistochemistry.

Methods

We included patients with endometrioid (n?=?180) and clear cell (n?=?165) ovarian carcinoma identified from the Alberta Cancer Registry between 1979 and 2010 for whom we abstracted medical records and constructed tumor tissue microarrays (TMAs). A concurrent diagnosis of endometrial cancer was obtained from the medical chart. We used unconditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and Cox proportional hazards models to estimate hazard ratios (HRs) and 95% CIs. Protein expression in ovarian tumors of patients with and without SEOs was evaluated using Fisher’s exact test.

Results

Comparing 52 patients with SEO tumors to 293 patients with endometrioid or clear cell ovarian carcinomas, endometriosis at the ovary (OR?=?0.45, 95% CI?=?0.23–0.87, p?=?0.02) was the strongest predictor of decreased risk in multivariable models. Premenopausal status (OR?=?2.17, 95% CI?=?0.92–5.13, p?=?0.08) and lower pre-treatment CA125 levels (OR?=?0.17, 95% CI?=?0.02–1.32, p?=?0.09) showed weaker associations. There were no significant differences in survival between patients with or without SEO tumors. More patients with SEO tumors compared to endometrioid ovarian carcinoma were deficient in MLH1, PMS2 and PTEN (p?≤?0.03).

Conclusions

Endometriosis may not be the mechanism by which SEO cancers arise. Altered tumor oncoprotein expression between women with and without SEOs indicates important biological differences although this did not translate into prognostic differences.

     

A clinically applicable molecular-based classification for endometrial cancers

Background:

Classification of endometrial carcinomas (ECs) by morphologic features is inconsistent, and yields limited prognostic and predictive information. A new system for classification based on the molecular categories identified in The Cancer Genome Atlas is proposed.

Methods:

Genomic data from the Cancer Genome Atlas (TCGA) support classification of endometrial carcinomas into four prognostically significant subgroups; we used the TCGA data set to develop surrogate assays that could replicate the TCGA classification, but without the need for the labor-intensive and cost-prohibitive genomic methodology. Combinations of the most relevant assays were carried forward and tested on a new independent cohort of 152 endometrial carcinoma cases, and molecular vs clinical risk group stratification was compared.

Results:

Replication of TCGA survival curves was achieved with statistical significance using multiple different molecular classification models (16 total tested). Internal validation supported carrying forward a classifier based on the following components: mismatch repair protein immunohistochemistry, POLE mutational analysis and p53 immunohistochemistry as a surrogate for ‘copy-number'' status. The proposed molecular classifier was associated with clinical outcomes, as was stage, grade, lymph-vascular space invasion, nodal involvement and adjuvant treatment. In multivariable analysis both molecular classification and clinical risk groups were associated with outcomes, but differed greatly in composition of cases within each category, with half of POLE and mismatch repair loss subgroups residing within the clinically defined ‘high-risk'' group. Combining the molecular classifier with clinicopathologic features or risk groups provided the highest C-index for discrimination of outcome survival curves.

Conclusions:

Molecular classification of ECs can be achieved using clinically applicable methods on formalin-fixed paraffin-embedded samples, and provides independent prognostic information beyond established risk factors. This pragmatic molecular classification tool has potential to be used routinely in guiding treatment for individuals with endometrial carcinoma and in stratifying cases in future clinical trials.     

Molecular biomarkers for uterine leiomyosarcoma and endometrial stromal sarcoma

Uterine leiomyosarcoma (u‐LMS) and endometrial stromal sarcoma (ESS) are among the most frequent soft tissue sarcomas, which, in adults, lead to fatal lung metastases and patients have an extremely poor prognosis. Due to their rarity and heterogeneity, there are no suitable biomarkers for diagnosis and prognosis, although some biomarker candidates have appeared. In 2017, The Cancer Genome Atlas (TCGA) Research Network's work on u‐LMS has confirmed mutations and deletions in RB1, TP53 and PTEN. In addition, whole‐exome sequencing of u‐LMS has confirmed and demonstrated frequent alterations in TP53, RB1, α‐thalassemia/mental retardation syndrome X‐linked (ATRX) and mediator complex subunit 12 (MED12). MED12 is a useful biomarker to diagnose uterine‐derived LMS and tumors arising from (LM) with a relatively favorable prognosis. TP53 and ATRX mutations can be important mechanisms in the pathogenesis of u‐LMS and are correlated with a poor prognosis. In an update based on the 2014 WHO classification, low‐grade ESS is often associated with gene rearrangement bringing about the JAZF 1‐SUZ12 (formerly JAZF1‐JJAZ1) fusion gene, whereas high‐grade ESS is associated with the YWHAE‐NUTM fusion gene. Low‐grade ESS with JAZF1 rearrangement may correlate with metastasis. However, high‐grade ESS with metastasis with YWHAE rearrangement shows a relatively favorable prognosis. The genetic/molecular genetic aberrations in u‐LMS and ESS are reviewed, focusing on molecular biomarkers for these primary and metastatic tumors.     

Ovarian metastasis in patient with endometrial carcinoma

Objective： To study the clinical pathological characteristics of ovarian metastasis of endometrial carcinoma and the factors affecting prognosis. Methods： Retrospective analysis was made to the clinical pathological outcome of endometrial carcinoma patients receiving surgical treatment in our hospital from January 1990 to December 2002. Results： Among the 191 cases of endometrial carcinoma patients, 17 cases （8.9%） had ovarian metastasis and young patients were more likely to have ovarian metastasis. The multiple factor analysis showed that the independent risk factors of ovarian metastasis in endometrial carcinoma included the depth of myometrial invasion, lymph node metastasis and pathological types. Conclusion： Ovarian metastasis in patients with endometrial carcinoma is associated with poor prognosis, the depth of myometrial invasion, lymph node metastasis and histologic types are independent risk factors affecting the prognosis. For young patients at early stage of the disease, it should be prudent as to whether to retain the ovary.     

Survival of patients with structurally-grouped TP53 mutations in ovarian and breast cancers

The objective of this study was to determine if ovarian cancer patients with a TP53 mutation grouped by location of the mutation within the p53 protein structure exhibit differential survival outcomes. Data from patients with high grade serous ovarian cancer (HGS OvCa) (N = 316) or breast cancer (BrCa) (N = 981) sequenced by The Cancer Genome Atlas (TCGA) was studied by Kaplan-Meier and Cox proportional hazards survival analysis. A TP53 DNA binding domain (BD) missense mutation (MM) occurred in 58.5% (185/316) of HGS OvCas and 16.8% (165/981) of BrCas. Patients with a TP53 DNA BD MM grouped by structural location had significantly different overall survival (OS) and progression free survival (PFS). Median OS (months) of HGS OvCa patients by structural group were: Sheet-loop-helix stabilizers, 31.1; DNA minor groove residue R248, 33.6; Wild-type, 34.2; all other MMs, 44.5; DNA major groove residues, 84.1, and zinc ion coordinating residues, 87.0 (log-rank p = 0.006). PFS of DNA major groove MM cases was longer than TP53 wild-type cases (19.1 versus 10.1 months, log-rank p = 0.038). HGS OvCa and BrCa patients with structurally-grouped TP53 DNA BD MMs have different survival outcomes.     

Mutations of TP53 do not correlate with the sensitivity to paclitaxel--a study using 27 gynaecological cancer cell lines

The correlation between inactivation of the TP53 gene through mutation or the presence of high-risk human papillomavirus (HPV) DNA and intrinsic paclitaxel sensitivity was studied in 27 gynaecological cancer cell lines. IC(50) values, as a measure of drug sensitivity, were determined using a 96-well clonogenic assay. TP53 mutations were investigated with polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct DNA sequencing. HPV status was studied with PCR using HPV consensus primers. TP53 mutations were found in 7/11 vulvar SCC cell lines. Only 2/9 endometrial and 1/7 ovarian cancer cell lines carried TP53 mutations. One vulvar and one endometrial cancer cell line were HPV-positive; both carrying HPV type-16 DNA. Thus, TP53 was functionally normal in 3/11 vulvar, 6/9 endometrial and 6/7 ovarian cancer cell lines. The IC(50) values for paclitaxel were 0.60-2.9, 0.49-2.3 and 0.40-3.4 nM in the vulvar, endometrial and ovarian cancer cell lines, respectively. No correlation could be demonstrated between inactivation of the TP53 gene and paclitaxel sensitivity in vitro; the cell lines were evaluated as one group or according to their anatomical origin or histology. Previous reports have given inconclusive results, partly due to the cell types used, i.e. normal, cancerous or transformed cells. Our results support the view that paclitaxel sensitivity of tumour-derived cancer cell lines is not related to the TP53 status.     

<Emphasis Type="Italic">TP53</Emphasis> Arg72Pro polymorphism and endometrial cancer risk: a meta-analysis

Studies investigating the relationship between TP53 Arg72Pro polymorphism and endometrial cancer risk reported conflicting results. To explore a more precise estimate of the effect of this polymorphism on endometrial carcinogenesis, a meta-analysis was performed by searching eligible studies in PubMed. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association for codominant model (Arg/Arg vs. Pro/Pro, Arg/Pro vs. Pro/Pro), dominant model (Arg/Arg + Arg/Pro vs. Pro/Pro), and recessive model (Arg/Arg vs. Arg/Pro + Pro/Pro), respectively. Subgroup analyses were performed by Hardy–Weinberg equilibrium (HWE) in controls, the specimen of cases for determining TP53 genotypes, sample size, the source of control and case groups, and ethnicity. We identified 8 case–control studies involving 2,154 subjects for this meta-analysis. Overall, no evidence of association was observed between TP53 genotypes and endometrial cancer risk in all genetic models (Arg/Arg vs. Pro/Pro: OR = 0.98, 95% CI: 0.69–1.39, P = 0.90; Arg/Pro vs. Pro/Pro: OR = 1.00, 95% CI: 0.71–1.42, P = 0.98; dominant model: OR = 0.99, 95% CI: 0.71–1.38, P = 0.95; recessive model: OR = 1.06, 95% CI: 0.80–1.41, P = 0.95). Stratified analyses also detected no significant association in any subgroup, except among those studies with controls deviated from HWE in recessive model (OR = 1.60, 95% CI: 1.07–2.39). In conclusion, we did not observe any evidence for a role of TP53 Arg72Pro polymorphism in endometrial cancer. The reported significant association between this polymorphism and endometrial cancer risk may be due to methodological errors such as selection bias, small sample size, Type I error, and population stratification.     

Alterations of theTP53 gene and TP53 protein expression in epithelial ovarian cancer before and after chemotherapy

Background A role for theTP53 (alias p53) tumor-suppressor gene in chemoresistance has recently been discussed, but little is known about the clinical relevance of theTP53 gene to chemoresistance. To elucidate the relevance ofTP53 status to chemoresistance, we investigated theTP53 gene and TP53 protein expression in tumors from the same patients, before and after chemotherapy. Methods Twenty-one patients with ovarian cancer, who had residual disease after primary surgery, were studied. These patients received chemotherapy consisting of cisplatin, doxorubicin, and cyclophosphamide, and then underwent a second surgery. Polymerase chain reaction-single strand conformation polymorphism analysis and cycle sequencing were performed to determineTP53 mutation. TP53 protein was detected by Western blot analysis. Results Of the 21 patients studied, 9 responded to chemotherapy. Mutation of theTP53 gene was seen in 7 patients (2 responders and 5 nonresponders) before chemotherapy. After chemotherapy, another mutation of the gene was observed in 5 patients, all of whom were nonresponders. TP53 protein was detected in 10 patients (3 responders and 7 nonresponders) before chemotherapy. After chemotherapy, the expression of TP53 protein increased in these 3 nonresponders, and became positive in 2 other nonresponders. Conclusions This study showed for the first time in clinical investigation that alterations toTP53 could develop in association with chemotherapy, and thatTP53 status may relate to the mechanisms of chemoresistance in patients with epithelial ovarian cancer.     

Similar protein expression profiles of ovarian and endometrial high-grade serous carcinomas

Background:

Ovarian and endometrial high-grade serous carcinomas (HGSCs) have similar clinical and pathological characteristics; however, exhaustive protein expression profiling of these cancers has yet to be reported.

Methods:

We performed protein expression profiling on 14 cases of HGSCs (7 ovarian and 7 endometrial) and 18 endometrioid carcinomas (9 ovarian and 9 endometrial) using iTRAQ-based exhaustive and quantitative protein analysis.

Results:

We identified 828 tumour-expressed proteins and evaluated the statistical similarity of protein expression profiles between ovarian and endometrial HGSCs using unsupervised hierarchical cluster analysis (P<0.01). Using 45 statistically highly expressed proteins in HGSCs, protein ontology analysis detected two enriched terms and proteins composing each term: IMP2 and MCM2. Immunohistochemical analyses confirmed the higher expression of IMP2 and MCM2 in ovarian and endometrial HGSCs as well as in tubal and peritoneal HGSCs than in endometrioid carcinomas (P<0.01). The knockdown of either IMP2 or MCM2 by siRNA interference significantly decreased the proliferation rate of ovarian HGSC cell line (P<0.01).

Conclusions:

We demonstrated the statistical similarity of the protein expression profiles of ovarian and endometrial HGSC beyond the organs. We suggest that increased IMP2 and MCM2 expression may underlie some of the rapid HGSC growth observed clinically.     

Ⅰ、Ⅱ期子宫内膜癌MRI表现与病理对照研究

Objective： To analyze MRI features of FIGO stage Ⅰ and Ⅱ endometrial carcinoma and to study the value of MRI in assessing myometrial and cervical invasion of endometrial carcinoma. Methods： Thirty patients with surgicopathologically proven endometrial carcinoma were included in this retrospective study. All patients underwent Tl-weighted spin-echo, T2-weighted fast spin-echo and dynamic contrastenhanced fast multiplanar spoiled gradient echo sequences before surgery. The type, signal intensity and enhancement features of the tumors and the appearance of junctional zone or subendometrial enhancement were analyzed. The MRI diagnosis of myometrial and cervical invasion was correlated with pathologic findings.Results： Endometrial carcinoma demonstrated diffuse widening of endometrial stripe （n=14） or polypoid or large mass in the endometrial cavity （n=16）. The tumors were usually isointense relative to the myometrium on TlWI and hyperintensity on T2WI. In the first phase of dynamic contrast-enhanced sequences, diffuse endometrial carcinoma usually showed mild （n=8） or moderate （n=5） enhancement, while focal endometrial carcinoma tended to enhance markedly （n=6） or moderately （n=9）. On T2WI junctional zone was seen in 18 cases. On dynamic contrast-enhanced images subendometrial enhancement was seen in 17 cases. The sensitivity, specificity and diagnostic accuracy of dynamic contrast-enhanced images in combination with T2WI were 87.5%, 95.5% and 93.3% for assessing deep myometrial invasion, and 75%, 95.5% and 90% for assessing cervical invasion. Conclusion： MRI is accurate and reliable in the evaluation of myometrial and cervical invasion of endometrial carcinoma, and should be performed as preoperative routine examination.     

Identification of a highly lethal V3+TP53+ subset in ALK+ lung adenocarcinoma

Tyrosine kinase inhibitors (TKI) have improved prognosis in metastatic anaplastic lymphoma kinase (ALK)-driven lung adenocarcinoma, but patient outcomes vary widely. We retrospectively analyzed the clinical course of all cases with assessable baseline TP53 status and/or ALK fusion variant treated at our institutions (n = 102). TP53 mutations were present in 17/87 (20%) and the echinoderm microtubule-associated protein-like 4 (EML4)-ALK variant 3 (V3) in 41/92 (45%) patients. The number of metastatic sites at diagnosis was affected more by the presence of V3 than by TP53 mutations, and highest with both factors (mean 5.3, p < 0.001). Under treatment with ALK TKI, progression-free survival (PFS) was shorter with either TP53 mutations or V3, while double positive cases appeared to have an even higher risk (hazard ratio [HR] = 2.9, p = 0.015). The negative effect of V3 on PFS of TKI-treated patients was strong already in the first line (HR = 2.5, p = 0.037) and decreased subsequently, whereas a trend for PFS impairment under first-line TKI by TP53 mutations became stronger and statistically significant only when considering all treatment lines together. Overall survival was impaired more by TP53 mutations (HR = 4.9, p = 0.003) than by V3 (HR = 2.4, p = 0.018), while patients with TP53 mutated V3-driven tumors carried the highest risk of death (HR = 9.1, p = 0.02). Thus, TP53 mutations and V3 are independently associated with enhanced metastatic spread, shorter TKI responses and inferior overall survival in ALK⁺ lung adenocarcinoma. Both markers could assist selection of cases for more aggressive management and guide development of novel therapeutic strategies. In combination, they define a patient subset with very poor outcome.     

Association of the germline TP53 R72P and MDM2 SNP309 variants with breast cancer survival in specific breast tumor subgroups

The tumor suppressor gene TP53 and its regulator MDM2 are both important players in the DNA-damage repair “TP53 response pathway”. Common germline polymorphisms in these genes may affect outcome in patients with tumors characterized by additional somatic changes in the same or a related pathway. To evaluate this hypothesis, we determined the effect of the common germline TP53 R72P and MDM2 SNP309 polymorphisms on breast cancer survival in a consecutive cohort of breast cancer patients (age at diagnosis <53 years, n = 295) with gene expression data available. Patients were classified in subgroups according to their tumor TP53 mutation status and three gene expression profiles; a TP53 mutation status expression signature, a PTEN/PI3K pathway signature and the 70-gene prognosis profile. Survival analyses were performed using Cox regression models adjusting for clinico-pathological characteristics and treatment. An increase in breast cancer-specific mortality was observed for carriers of the germline MDM2 SNP309 rare GG-genotype (range hazard ratios: 2–3) or TP53 R72P heterozygous GC-genotype (range hazard ratios: 1–2) compared to those having the common genotypes within subgroups of tumors displaying a “more aggressive phenotype” gene expression profile. There was no evidence of such an effect on survival within the TP53-mutated tumor group for TP53 R72P carriers but a suggestion of an effect for MDM2 SNP309 carriers (GG vs. TT-genotype HR 2.99, P = 0.06). These results indicate that common polymorphisms in specific pathways may add to the worse prognosis of patients with tumors in which these pathways are affected by somatic alterations.     

Loss-of-heterozygosity on chromosome 19q in early-stage serous ovarian cancer is associated with recurrent disease

ABSTRACT: BACKGROUND: Ovarian cancer is a heterogeneous disease and prognosis for apparently similar cases of ovarian cancer varies. Recurrence of the disease in early stage (FIGO-stages I-II) serous ovarian cancer results in survival that is comparable to those with recurrent advanced-stage disease. The aim of this study was to investigate if there are specific genomic aberrations that may explain recurrence and clinical outcome. METHODS: Fifty-one women with early stage serous ovarian cancer were included in the study. DNA was extracted from formalin fixed samples containing tumor cells from ovarian tumors. Tumor samples from thirty-seven patients were analysed for allele-specific copy numbers using OncoScan single nucleotide polymorphism arrays from Affymetrix and the bioinformatic tool Tumor Aberration Prediction Suite. Genomic gains, losses, and loss-of-heterozygosity that associated with recurrent disease were identified. RESULTS: The most significant differences (p < 0.01) in Loss-of-heterozygosity (LOH) were identified in two relatively small regions of chromosome 19; 8.0-8,8 Mbp (19 genes) and 51.5-53.0 Mbp (37 genes). Thus, 56 genes on chromosome 19 were potential candidate genes associated with clinical outcome. LOH at 19q (51-56 Mbp) was associated with shorter disease-free survival and was an independent prognostic factor for survival in a multivariate Cox regression analysis. In particular LOH on chromosome 19q (51-56 Mbp) was significantly (p < 0.01) associated with loss of TP53 function. CONCLUSIONS: The results of our study indicate that presence of two aberrations in TP53 on 17p and LOH on 19q in early stage serous ovarian cancer is associated with recurrent disease. Further studies related to the findings of chromosomes 17 and 19 are needed to elucidate the molecular mechanism behind the recurring genomic aberrations and the poor clinical outcome.     

Establishing the origin of metastatic deposits in the setting of multiple primary malignancies: The role of massively parallel sequencing

In this proof‐of‐principle study, we sought to define whether targeted capture massively parallel sequencing can be employed to determine the origin of metastatic deposits in cases of synchronous primary malignancies and metastases in distinct anatomical sites. DNA samples extracted from synchronous tumor masses in the breast, adnexal, and pelvic‐peritoneal regions from a 62‐year‐old BRCA1 germline mutation carrier were subjected to targeted massively parallel sequencing using a platform comprising 300 cancer genes known to harbor actionable mutations. In addition to BRCA1 germline mutations, all lesions harbored somatic loss of the BRCA1 wild‐type allele and TP53 somatic mutations. The primary breast cancer displayed a TP53 frameshift (p.Q317fs) mutation, whereas and the adnexal lesion harbored a TP53 nonsense (p.R213*) mutation, consistent with a diagnosis of two independent primary tumors (i.e. breast and ovarian cancer). The adnexal tumor and all pelvic‐peritoneal implants harbored identical TP53 (p.R213*) and NCOA2 (p.G952R) somatic mutations. Evidence of genetic heterogeneity within and between lesions was observed, both in terms of somatic mutations and copy number aberrations. The repertoires of somatic genetic aberrations found in the breast, ovarian, and pelvic‐peritoneal lesions provided direct evidence in support of the distinct origin of the breast and ovarian cancers, and established that the pelvic‐peritoneal implants were clonally related to the ovarian lesion. These observations were consistent with those obtained with immunohistochemical analyses employing markers to differentiate between carcinomas of the breast and ovary, including WT1 and PAX8. Our results on this case of a patient with BRCA1‐mutant breast and ovarian cancer demonstrate that massively parallel sequencing may constitute a useful tool to define the relationship, clonality and intra‐tumor genetic heterogeneity between primary tumor masses and their metastatic deposits in patients with multiple primary malignancies and synchronous metastases.     

Distinct sets of gene alterations in endometrial carcinoma implicate alternate modes of tumorigenesis

BACKGROUND: Endometrial carcinomas seem to carry a different prognosis depending on the presence or absence of concomitant complex atypical hyperplasia (hyperplasia). The molecular genetic profile of these two pathogenetic types, based on the genes reportedly mutated in these cancers, remains to be defined. Although microsatellite inability is reported in approximately 25% of endometrial carcinomas, its relation with the 2 pathogenetic types is not investigated. METHODS: To elucidate their underlying genetic changes, we analyzed 53 sporadic endometrial tumors, including 19 with and 34 without hyperplasia, for microsatellite instability (MSI), DNA ploidy (by flow cytometry), and for mutations in different genes. RESULTS: Microsatellite instability was present in 21%, DNA nondiploidy in 15%, and mutations in the PTEN, KRAS, CTNNB1/beta-catenin, TP53, and CDKN2A genes were detected in 32, 11, 13, 17, and 0% of the tumors, respectively. Microsatellite instability and mutations in these genes were present in tumors both with and without complex atypical hyperplasia. All cases with complex atypical hyperplasia were early stage (I-II) endometrioid tumors and associated with long progression free disease (P = 0.0004). Furthermore, most tumors with hyperplasia had low World Health Organization or International Federation of Gynecology and Obstetrics grade, had less myometrial invasion, and showed expression of estrogen receptors. All MSI tumors were diploid and had a significantly higher rate of PTEN mutations, but similar rates of KRAS, beta-catenin, and TP53 mutations compared with microsatellite stable tumors. TP53 mutations more often were found in nondiploid tumors but never in tumors with PTEN, KRAS, or beta-catenin mutations, and all PTEN mutations occurred in diploid tumors. CONCLUSIONS: Thus, PTEN, KRAS, beta-catenin, and TP53 mutations occurred in tumors both with and without hyperplasia, but PTEN and TP53 mutations were more common in tumors without hyperplasia. However, none of these genes seems to clearly distinguish tumors with and without hyperplasia, suggesting that other factors may be involved. Conversely, alterations in the PTEN and TP53 genes seem to define distinct subgroups of endometrial carcinoma, the former associated with diploidy and MSI, the latter with macroscopic chromosomal instability.     

High prevalence of codon 213ARG→STOP mutations of the TP53 gene in human ovarian cancer in the southwestern part of The Netherlands

As in many human malignancies, TP53 mutations are the most common genetic alterations in malignant human ovarian tumours. An approach often used in the determination of TP53 status is immunohistochemical staining of the protein. Non-missense mutations, especially those of the null type, causing premature termination codons and resulting in truncated proteins, may often not be detectable by immunohistochemistry. Therefore, current estimates of TP53 alterations in ovarian cancer may be inaccurate. By using polymerase chain reaction-single strand conformation polymorphism analysis and sequencing techniques, we have found a high prevalence of TP53 non-missense mutations in exons 5–8 in ovarian tumour specimens from patients from the southwestern part of The Netherlands. Twenty-nine of 64 tumours showed mutations, of which 10 were non-missense mutations. The majority (9 of 10) of these non-missense mutations, including 7 nonsense mutations and 2 frameshift deletions, were null type mutations and could not be detected by immunohistochemical staining. Five of the 7 nonsense mutations were mutations at codon 213 (Arg|iOStop). The nature of the high prevalence of this nonsense mutation in our series of ovarian carcinomas remains unknown. In addition to the 9 null type mutations, a splice junction mutation was encountered. In conclusion, we have observed a high prevalence (13%) of ovarian tumours with null type mutations in exons 5–8 that did not result in immunostaining. Our data suggest that, especially in ovarian cancer, immunological assessment of TP53 is not an adequate tool to study TP53 alteration. A frequent nonsense mutation at codon 213 in 5 (8%) of 64 tumour specimens represents an important finding. Int J. Cancer 76:299–303, 1998.© 1998 Wiley-Liss, Inc.     

Chromatin remodelling and DNA repair genes are frequently mutated in endometrioid endometrial carcinoma

In developed countries, endometrial carcinoma is the most common cancer that affects the female genital tract. Endometrial carcinoma is divided into two main histological types, type I or endometrioid and type II or non‐endometrioid, each of which have characteristic, although not exclusive, molecular alterations and mutational profiles. Nevertheless, information about the implication and relevance of some of these genes in this disease is lacking. We sought here to identify new recurrently mutated genes in endometrioid cancers that play a role in tumourigenesis and that influence the clinical outcome. We focused on low‐grade, non‐ultramutated tumours as these tumours have a worse prognosis than the ultramutated POLE‐positive endometrioid endometrial carcinomas (EECs). We performed exome‐sequencing of 11 EECs with matched normal tissue and subsequently validated 15 candidate genes in 76 samples. For the first time, we show that mutations in chromatin remodelling‐related genes (KMT2D, KMT2C, SETD1B and BCOR) and in DNA‐repair‐related genes (BRCA1, BRCA2, RAD50 and CHD4) are frequent in this subtype of endometrial cancer. The alterations to these genes occurred with frequencies ranging from 35.5% for KMT2D to 10.5% for BRCA1 and BCOR, with some showing a tendency toward co‐occurrence (RAD50‐KMT2D and RAD50‐SETD1B). All these genes harboured specific mutational hotspots. In addition, the mutational status of KMT2C, KMT2D and SETD1B helps to predict the degree of myometrial invasion, a critical prognostic feature. These results highlight the possible implication of these genes in this disease, creating opportunities for new therapeutic approaches.     

Long‐term oncological outcomes of ovarian serous carcinomas with psammoma bodies: A novel insight into the molecular pathogenesis of ovarian epithelial carcinoma

A two‐tier system in which ovarian epithelial carcinomas are subdivided into type I and type II tumors has been proposed on the basis of recent molecular pathogenesis findings. Type I tumors, unrelated to tumor protein p53 (TP53) mutations, show favorable prognosis in a slow step‐wise process, whereas type II tumors, related to TP53 mutations, contribute to poor prognosis. Ovarian serous carcinomas with excessive psammoma bodies behave like type I tumors. However, their etiology and prognostic significance remain obscure. The objective of the present study was to evaluate the characteristic features and potential relevance of psammoma bodies to the clinical outcome of 44 patients with serous carcinomas with long‐term follow‐up. The 5‐ and 10‐year survival rates were significantly different between the serous carcinomas with less than 5% area of psammoma bodies and those at least 5% area (P < 0.01). All tumors with at least 5% area were both diploid and immunohistochemically negative for TP53 mutations. All patients with these tumors, including eight with International Federation of Gynecology and Obstetrics (FIGO) stages III or IV disease, survived more than 5 years and their 10‐year survival rate was 76%. In multivariate analysis using clinical parameters, the apparent existence of psammoma bodies was an indication to view serous carcinomas as type I tumors with long‐term survival. Our results suggested that the formation of psammoma bodies is associated with increased apoptotic tumor cell death related to normal TP53 function. The pathological findings of psammoma bodies might contribute to the consideration of pathogenesis and to the development of prognostic prediction rules for serous carcinomas. (Cancer Sci 2010)