Overexpression of p53 is not a feature of ovarian granulosa cell tumors

Immunohistochemical markers of prognosis in adult granulosa cell tumors of the ovary - a review

BACKGROUND

Granulosa cell tumors (GCT) are rare malignant ovarian tumors. The two subtypes, adult and juvenile granulosa cell tumors, differ in clinical and molecular characteristics. GCT are low-malignant tumors and are generally associated with favorable prognosis. However, relapses are common even years and decades after diagnosis. Prognostic and predictive factors are difficult to assess in this rare tumor entity. The purpose of this review is to provide a comprehensive overview of the current state of knowledge on prognostic markers of GCT to identify patients with a high risk of recurrence.

METHODS

Systematic research for adult ovarian granulosa cell tumors and prognosis revealed n = 409 English full text results from 1965 to 2021. Of these articles, n = 35 were considered for this review after title and abstract screening and topic-specific matching. A specific search for pathologic markers with prognostic relevance for GCT identified n = 19 articles that were added to this review.

RESULTS

FOXL2 mutation and FOXL2 mRNA were inverse and immunohistochemical (IHC) expression of CD56, GATA-4 and SMAD3 was associated with reduced prognosis. IHC analysis of estrogen receptor, Anti-Mullerian hormone (AMH) and inhibin was not associated with prognosis for GCT. Analyses of mitotic rate, Ki-67, p53, β-catenin and HER2 revealed inconsistent results.

Nuclear localization of E-cadherin but not beta-catenin in human ovarian granulosa cell tumours and normal ovarian follicles and ovarian stroma

AIMS

The role of misregulated Wnt/beta-catenin signalling in human ovarian granulosa cell tumour (GCT) has not been well characterized. The aim of this study was to confirm subcellular localization of key molecules of Wnt signalling (beta-catenin and E-cadherin) in human ovarian GCTs.

METHODS AND RESULTS

Tissue samples taken from 32 human ovarian GCTs and 19 human normal ovaries containing 68 follicles were stained immunohistochemically using monoclonal anti-beta-catenin and anti-E-cadherin antibodies. None of the 32 GCTs and none of the 68 ovarian follicles showed beta-catenin nuclear expression (0%). On the other hand, 28 of 32 GCTs (88%) and 53 of 68 normal ovarian follicles (78%) showed nuclear expression of E-cadherin in granulosa cells. The ovarian stroma in all 19 normal ovaries showed nuclear expression of E-cadherin but not beta-catenin. Membranous and cytoplasmic expression was observed variously in ovarian GCT, follicles and stroma.

CONCLUSIONS

We have confirmed frequent nuclear localization of E-cadherin but not beta-catenin in human ovarian GCT, ovarian follicles and stroma. There is no evidence of misregulated Wnt/beta-catenin signalling (represented by nuclear expression of beta-catenin) in human ovarian GCT. Nuclear translocation of E-cadherin might contribute to ovarian folliculogenesis or granulosa/stromal cell differentiation.

The new molecular biology of granulosa cell tumors of the ovary

Granulosa cell tumors (GCTs) of the ovary belong to the group of ovarian sex-cord stromal tumors and represent 5 to 10% of ovarian malignancies. GCTs exhibit several morphological, biochemical and hormonal features of normal proliferating pre-ovulatory granulosa cells, such as estrogen biosynthesis. Prognostic factors of this condition are lacking, and alternative treatment options to preserve future fertility are needed. Several groups have shown that two genetic factors implicated in GCTs are of particular interest. The gsp oncogene is a constitutive activating mutation of the prognosis of the tumor. FOXL2 is a transcription factor gene involved in ovarian development and function, whose expression is reduced and which is mutated in the majority of GCTs. FOXL2 appears to play a major role in cell cycle regulation. These recent findings open new pathophysiological insights into GCT development as well as revisitation of granulosa cell and ovarian function.

Mutation of FOXL2 in granulosa-cell tumors of the ovary

BACKGROUND

Granulosa-cell tumors (GCTs) are the most common type of malignant ovarian sex cord-stromal tumor (SCST). The pathogenesis of these tumors is unknown. Moreover, their histopathological diagnosis can be challenging, and there is no curative treatment beyond surgery.

METHODS

We analyzed four adult-type GCTs using whole-transcriptome paired-end RNA sequencing. We identified putative GCT-specific mutations that were present in at least three of these samples but were absent from the transcriptomes of 11 epithelial ovarian tumors, published human genomes, and databases of single-nucleotide polymorphisms. We confirmed these variants by direct sequencing of complementary DNA and genomic DNA. We then analyzed additional tumors and matched normal genomic DNA, using a combination of direct sequencing, analyses of restriction-fragment-length polymorphisms, and TaqMan assays.

RESULTS

All four index GCTs had a missense point mutation, 402C-->G (C134W), in FOXL2, a gene encoding a transcription factor known to be critical for granulosa-cell development. The FOXL2 mutation was present in 86 of 89 additional adult-type GCTs (97%), in 3 of 14 thecomas (21%), and in 1 of 10 juvenile-type GCTs (10%). The mutation was absent in 49 SCSTs of other types and in 329 unrelated ovarian or breast tumors.

CONCLUSIONS

Whole-transcriptome sequencing of four GCTs identified a single, recurrent somatic mutation (402C-->G) in FOXL2 that was present in almost all morphologically identified adult-type GCTs. Mutant FOXL2 is a potential driver in the pathogenesis of adult-type GCTs.

[Juvenile granulosa-cell tumor: clinical and molecular expression]

Ovarian sex cord-stromal tumors are rare tumors that originate from the nongerminal cells of ovary. Two decades ago, the identification of juvenile granulosa-cell tumors (GCT), as a specific entity inside this group, allowed a better treatment of these tumors in children. However, little data have been reported on the natural course of the disease and reliable prognostic factors have not been yet defined. We here review the clinical and genetics aspects of granulosa tumors, based on a series of 40 children. This national collaborative study involved the French Society of Children Cancer and eight clinical departments of pediatric endocrinology. We found that early diagnosis of a tumor, revealed by clinical signs of hyperoestrogeny, is an important prognostic factor. The pathophysiology of these tumors is still debatable and several cellular- and molecular-abnormal signals could be implicated in their development. The role of growth factors and oncogenes through the signaling pathway of MAP kinase is still discussed. According to our data, FSH signaling-transduction pathway, such as a constitutionally activated Galphas, could also be implicated in the induction of granulosa cell proliferation and seems to modulate the invasiveness of the tumor. Last, we have described a low-expression pattern or an extinction of an ovarian-determination gene, FOXL2, which is related to a worse prognosis of this tumor.

Expression of CD56 isoforms in primary and relapsed adult granulosa cell tumors of the ovary

BACKGROUND

Adult granulosa cell tumors of the ovary (GCTs) are sex cord stromal tumors of unpredictable behaviour. Up to now, the prediction of the relapsing/malignant potential remains difficult. CD56 (NCAM) in GCTs was previously described in only two studies. However, the expression of its isoforms was not examined.

METHODS

30 GCTs (16 primaries, 14 relapses) were investigated immunohistochemically with antibodies against Pan-CD56 (CD56Pan) and the isoform with 140/180 kDa length (CD56140/180 kDa). The reaction was assessed with respect to percentage of positive cells and intensity of staining.

RESULTS

In all GCTs, CD56Pan was expressed, but differences were found between primaries and relapses. The percentage of CD56Pan positive tumor cells was lower in relapses, whereas CD56140/180 kDa showed a higher staining intensity in the latter.

CONCLUSION

Expression of CD56 is an additional sensitive and helpful immunohistochemical tool for histopathologists diagnosing a GCT. It does not seem possible to provide a validly individual risk assessment. However, the different expression of CD56 isoforms might indicate important changes in the course to a more malignant behaviour.

Management of ovarian stromal cell tumors

PURPOSE

To describe the clinical management of ovarian stromal cell tumors, which are a heterogeneous group of neoplasms that develop from the sex cords and the ovarian stroma.

DESIGN

We reviewed the current evidence on the clinical management of these relatively rare ovarian malignancies, which are typically detected at an early stage and may recur as late as 30 years following the initial treatment. The overall prognosis is favorable with a long-term survival ranging from 75% to 90% for all stages. Adult granulosa cell tumor (GCT) is the most common malignancy among these tumors.

RESULTS

Surgery is the cornerstone of initial treatment. In women of childbearing age and with disease limited to one ovary, a fertility-sparing surgery can be a reasonable approach. Tumor stage represents the most important clinical parameter of prognostic relevance. The value of postoperative adjuvant therapy for high-risk patients has not been proven by prospective randomized studies. Platinum-based chemotherapy is used currently for patients with advanced stages or recurrent disease, with an overall response rate of 63% to 80%. Taxane and platinum combination chemotherapy seems to be a reasonable candidate for future trials. Little evidence exists for the use of radiation or hormonal therapy, and these modalities should be restricted to selected cases. Given the propensity of GCT for late relapse, prolonged follow-up is required.

CONCLUSION

Surgery remains the most effective treatment for ovarian stromal tumors and, whenever feasible, for relapsing disease. Platinum-based chemotherapy is currently used in metastatic or recurrent tumors.

Misregulated Wnt/beta-catenin signaling leads to ovarian granulosa cell tumor development

Misregulation of the Wnt/beta-catenin signaling pathway is a hallmark of several forms of cancer. Components of the Wnt/beta-catenin pathway are expressed in ovarian granulosa cells; nevertheless, its potential involvement in granulosa cell tumorigenesis has not been examined. To this end, human (n = 6) and equine (n = 18) granulosa cell tumors (GCT) were analyzed for beta-catenin expression by immunohistochemistry. Unlike granulosa cells of normal ovaries, most (15 of 24) GCT samples showed nuclear localization of beta-catenin, suggesting that activation of the Wnt/beta-catenin pathway plays a role in the etiology of GCT. To confirm this hypothesis, Catnb(flox(ex3)/+); Amhr2(cre/+) mice that express a dominant stable beta-catenin mutant in their granulosa cells were generated. These mice developed follicle-like structures containing disorganized, pleiomorphic granulosa by 6 weeks of age. Even in older mice, these follicle-like lesions grew no larger than the size of antral follicles and contained very few proliferating cells. Similar to corpora lutea, the lesions were highly vascularized, although they did not express the luteinization marker Cyp11a1. Catnb(flox(ex3)/+); Amhr2(cre/+) females were also found to be severely subfertile, and fewer corpora lutea were found to form in response to exogenous gonadotropin compared with control mice. In older mice, the ovarian lesions often evolved into GCT, indicating that they represent a pretumoral intermediate stage. The GCT in Catnb(flox(ex3)/+); Amhr2(cre/+) mice featured many histopathologic similarities to the human disease, and prevalence of tumor development attained 57% at 7.5 months of age. Together, these studies show a causal link between misregulated Wnt/beta-catenin signaling and GCT development and provide a novel model system for the study of GCT biology.

Loss of oestrogen receptor beta, high PCNA and p53 expression and aneuploidy as markers of worse prognosis in ovarian granulosa cell tumours

AIMS

Ovarian granulosa cell tumour (OGCT) is a sex-cord stromal tumour with a general trend toward late relapse and/or metastasis. However, mortality rate corrected for long-term follow-up shows that about 50% of patients die within 20 years of diagnosis. Classical clinicopathological parameters are unable to predict the biological behaviour of OGCT. The involvement of a recently characterized subtype of oestrogen receptor, ERbeta, in ovarian carcinogenesis has been hypothesized.

METHODS AND RESULTS

We examined by immunohistochemistry the expression of ERbeta, proliferating cell nuclear antigen (PCNA) and p53 in a selected series of 30 OGCT, to evaluate their role in the prognostic evaluation of this tumour. Immunohistochemistry was performed on formalin-fixed paraffin-embedded sections. Results were compared with the DNA-ploidy of the tumours (evaluated by image analysis) and with the follow-up data of the patients.

CONCLUSIONS

Loss of ERbeta expression, high PCNA expression and aneuploidy, characterized a subgroup of OGCT with a worse outcome. The identification of a high-risk subclass of OGCT may be of primary importance in addressing appropriate therapeutic strategies, offering the chance to prevent relapses and metastases by using adjunctive, specifically targetted, more aggressive therapies.

Expression of p53, c-erbB-2, Ki-67, and CD34 in granulosa cell tumor of the ovary

The purpose of this study is to investigate the expression of p53, c-erbB-2, Ki-67, and angiogenic activity and their correlation with the clinicopathologic characteristics in a series of granulosa cell tumors of the ovary (GCTO). Eighteen GCTO cases assisted at the Department of Obstetrics and Gynecology, School of Medical Science, UNICAMP, after diagnostic confirmation by three pathologists, were submitted to immunohistochemistry for assessment of p53, c-erbB-2, Ki-67, and CD34 expressions. The mean tumor size was 13 cm (range: 4-30 cm). Six (33%) cases presented with extraovarian disease. Thirteen (72%) cases presented some solid diffuse or sarcomatoid pattern and six (33%) moderate or strong atypia. Fourteen cases presented </=2 mitoses/10 HPF. Thirteen cases were focally positive for Ki-67. The mean Ki-67 proliferative index was 1.0%. One case presented positive expression for mutant p53 but all cases were negative for c-erbB-2 expression. The mean microvascular density was 28.9/mm2 (range: 0-50). No significant correlations could be established between the biologic markers and clinicopathologic variables. GCTO showed a markedly low rate of immunohistochemical staining for p53 or c-erbB-2 overexpression/amplification, as well as low proliferative and angiogenic activities. Further studies are urgently needed to elaborate the factors responsible for the highly unpredictable clinical course of GCTO.

Evidence of a role for the INK4 family of cyclin-dependent kinase inhibitors in ovarian granulosa cell tumors

Granulosa cell tumors (GCTs) of the ovary are relatively rare and account for <5% of all ovarian cancers. The molecular pathogenesis of these tumors is not well understood. We tested the hypothesis that cyclin-dependent kinase inhibitors, specifically the inhibitors of the cyclin-dependent kinase 4 (INK4) family, are targets for altered gene expression in GCTs. The status of RB1, INK4A, INK4B, INK4C, INK4D, and ARF in 13 adult and 2 juvenile ovarian GCTs was determined by reverse transcription-polymerase chain reaction of total RNA and exon-specific sequencing of genomic DNA. Tumors showing loss of INK4A expression were assayed further by exon-deletion analysis and methylation-specific PCR. None of the juvenile tumors demonstrated altered expression, but 7/12 (58%) adult GCTs lacked expression of INK4A, INK4B, or both. In one of these cases, we noted a homozygous deletion of the INK4A locus, and in the remaining tumors we found hypermethylation of the promoter region, a mechanism that can lead to gene inactivation. These data support a role for the INK4 family of CDK inhibitors in the biology of GCTs.

Histopathological prognostic factors of adult granulosa cell tumors of the ovary

BACKGROUND

The prognostic factors of adult granulosa cell tumor (AGCT) have not been well defined.

METHODS

In 27 AGCT patients, we examined clinical stage, microscopic patterns, mitotic index (MI), and lymph-vascular space invasion (LVSI) to determine whether these factors were related to disease-free survival (DFS) of patients with AGCT. We also performed immunohistochemical examination for p53.

RESULTS

Seventeen cases represented stage I tumors, four stage II, five stage III, and one stage IV. Patients with stage I disease had more favorable prognosis than those with stage II to IV disease (p=0.034). There was no relation between the microscopic patterns and the DFS. The MI, which was categorized into < or =3/10 high power field (HPF) and > or =4/10 HPF, was significantly related to patients DFS (p<0.0005). The DFS time for patients with moderate or prominent LVSI was significantly shorter than that for patients with no or minimal LVSI (p<0.0001). By multivariate analysis, MI and LVSI were shown to be independent prognostic factors. Five of seven patients with recurrent tumor had extrapelvic spread; two in the abdominal cavity and three in the liver.

CONCLUSION

The results of this study suggest that prognosis for patients with AGCT depends on the MI and LVSI. During the follow-up period of patients, they need to be examined for distant metastasis including liver.

DNA replication error is frequent in ovarian granulosa cell tumors

DNA replication errors (RER) have been detected in epithelial ovarian cancers, as well as in other human tumor types. These observations suggest that this genetic defect is present in ovarian granulosa cell tumors, and that a DNA mismatch repair deficiency may be involved in their development and/or progression. We therefore assayed tissue samples from 29 patients with granulosa cell tumors for RER, using polymerase chain reaction (PCR) and 5 microsatellite markers. The RER were observed at greater than or equal to 1 loci in 15 (58%) of 26 informative cases. The incidence of RER was unrelated to the patient's age or the histologic subtype or clinical stage of the tumors. The RER, however, were observed in 57% (8/14) of the informative patients with stage IA disease. These findings suggest that a DNA mismatch repair deficiency may contribute to the pathogenesis of ovarian granulosa cell tumors, and that this deficiency may be an early event in their development and/or progression.

Assessment of inhibin and p53 in granulosa cell tumors of the ovary

OBJECTIVE

The goal of this work was to determine the cellular content of inhibin and p53 in granulosa cell tumors (GCTs).

METHODS

Clinical records of 47 patients (mean age, 54 years; range, 20-85 years) presenting with GCT surgically managed at our institution were abstracted. International Federation of Gynecology stage I was assigned in 39 patients, stage II in 2, and stage III in 6. Concomitant endometrial carcinoma was identified in 6 patients. Mean follow-up was 13.6 years (range, 1 day to 37.6 years). Sections from paraffin-embedded tissue blocks were analyzed immunohistochemically for expression of tissue inhibin and p53 levels. Inhibin expression was graded by intensity and reactivity, and p53, by its presence or absence.

RESULTS

The tumors of 27 patients (57%) stained strongly for inhibin intensity and showed >60% reactivity. Decreased intensity and reactivity of inhibin expression were associated with advanced-stage disease (P = 0.05 and P < 0.01, respectively, by Fisher exact test). Expression of p53 was detected in tumors from 27 patients (57%), and immunoreactivity was associated with compromised progression-free survival (P = 0.016, log-rank test). However, the association between p53 immunoreactivity and disease stage was not significant. Absence of p53 expression was significantly associated with concurrent endometrial carcinoma (P = 0.022), suggesting more molecularly intact tumors that retain functional activity.

CONCLUSIONS

Although the majority of GCTs show strong expression of inhibin with regard to intensity and reactivity, weak expression is associated with advanced disease but not with decreased progression-free survival. By contrast, expression of p53 is not significantly associated with stage, but increased expression is associated with decreased disease-free survival. Absence of p53 expression appears to be associated with concurrent endometrial carcinoma.

Prognostic significance of p53 expression in ovarian granulosa cell tumors

OBJECTIVE

The purpose of the study was to investigate the significance of p53 expression for the prognosis in patients with ovarian granulosa cell tumors (GCT).

METHODS

The records of 30 patients operated on for GCT at Tampere University Hospital, Finland, were reviewed. The mean age at the time of the diagnosis was 55 years. Twenty-one of the tumors were of FIGO stage I, three were of stage II, three were of stage III, and three were of stage IV. Paraffin-embedded tumor specimens were analyzed by immunohistochemistry for expression of mutated p53 protein and by flow cytometry.

RESULTS

Eleven tumors were positive for p53 and 19 were negative. The median crude survival of p53-negative patients was 10 times that of p53-positive ones (210 months vs 21 months, P = 0.037, log-rank test). The association between p53 immunoreactivity and stage was statistically significant (P = 0.026 Pearson chi2 test), while there was no association between p53 expression and DNA ploidy or S-phase fraction.

CONCLUSION

Although the results should be considered as preliminary, expression of mutated p53 in ovarian granulosa cell tumors seems to be associated with unfavorable prognosis.

Loss of heterozygosity at the alpha-inhibin locus on chromosome 2q is not a feature of human granulosa cell tumors

The alpha-inhibin gene has been shown in knockout mouse models to be a suppressor of granulosa tumorigenesis in the mouse. To determine if alpha-inhibin has the same function in humans, we have assessed the frequency of loss of heterozygosity (LOH) of the alpha-inhibin gene locus on chromosome 2q in 17 human granulosa cell tumors and 36 epithelial ovarian cancers. LOH was detected in 12 of 36 (33.3%) epithelial tumors but in only 1 of 17 (6%) granulosa cell tumors. These data suggest that in contrast to the suggestions from the mouse model alpha-inhibin does not function as a granulosa cell tumor suppressor gene in the human. Furthermore, analysis of the TP53 gene in the granulosa cell tumors failed to detect either LOH or point mutations, indicating that they have a developmental pathway distinct from that of epithelial ovarian tumors.