Cytochrome P17 inhibition with ketoconazole as treatment for advanced granulosa cell ovarian tumor

CRISPR targeting of FOXL2 c.402C>G mutation reduces malignant phenotype in granulosa tumor cells and identifies anti-tumoral compounds

Forkhead box L2 (FOXL2) encodes a transcription factor essential for sex determination, and ovary development and maintenance. Mutations in this gene are implicated in syndromes involving premature ovarian failure and granulosa cell tumors (GCTs). This rare cancer accounts for less than 5% of diagnosed ovarian cancers and is causally associated with the FOXL2 c.402C>G, p.C134W mutation in 97% of the adult cases (AGCTs). In this study, we employed CRISPR technology to specifically eliminate the FOXL2 c.402C>G mutation in granulosa tumor cells. Our results show that this Cas9-mediated strategy selectively targets the mutation without affecting the wild-type allele. Granulosa cells lacking FOXL2 c.402C>G exhibit a reduced malignant phenotype, with significant changes in cell proliferation and invasion. Furthermore, these modified cells are more susceptible to dasatinib and ketoconazole. Transcriptomic and proteomic analyses reveal that CRISPR-modified granulosa tumor cells shift their expression profiles towards a wild-type-like phenotype. Additionally, this altered expression signature has led to the identification of new compounds with antiproliferative and pro-apoptotic effects on granulosa tumor cells. Our findings demonstrate the potential of CRISPR technology for the specific targeting and elimination of a mutation causing GCTs, highlighting its therapeutic promise for treating this rare ovarian cancer.

Open-label phase II clinical trial of orteronel (TAK-700) in metastatic or advanced non-resectable granulosa cell ovarian tumors: the Greko II study (GETHI2013-01)

BACKGROUND

Granulosa cell ovarian tumors (GCTs) are a rare neoplasia characterized by a pathognomonic mutation in the FOXL2 gene. In vitro studies have demonstrated an overactivation of hormone activity due to this alteration. Thus, we aimed to determine the activity of orteronel, a CYP17 inhibitor, in advanced disease.

METHODS

We designed a multicentric open-label phase II clinical trial. Eligible patients were adult woman with advanced or unresectable GCTs. Primary objective was clinical benefit rate, defined as the average of patients with radiological response plus stable disease longer than 6 months.

RESULTS

From October 1, 2014 to May 20, 2016, ten patients were included in six participating institutions members of the GETTHI group. The study was terminated early due to a low recruitment rate. Up to 40% (CI 95% [9.6-70.4%]) cases presented a disease stabilization longer than 6 months and two of them, longer than 12 months. One patient continued on treatment at database closure 29 months after inclusion in the trial. No patient reached partial or complete response by RECIST criteria on the independent radiological review. The drug was well tolerated with nausea as the only grade 3 adverse event in one case.

CONCLUSION

Low accrual led to an early interruption of the study. However, orteronel achieved a promising clinical benefit rate that supports further development of new hormonotherapies in this tumor.

CLINICALTRIALS

GOV IDENTIFIER

NCT02101684.

Open-label phase II clinical trial of ketoconazole as CYP17 inhibitor in metastatic or advanced non-resectable granulosa cell ovarian tumors: the GREKO (GRanulosa Et KetOconazole) trial, GETHI 2011-03

BACKGROUND

Granulosa cell ovarian tumor (GCT) is characterized by a pathognomonic mutation in the FOXL2 gene (402 C > G) that leads to an overactivation of steroidogenesis. CYP17 is a key enzyme in such process and can be inhibited by ketoconazole.

METHODS

We designed a phase II clinical trial to assess the efficacy of ketoconazole in advanced GCT and conducted several in vitro studies to support the clinical findings.

RESULTS

From October 1st 2012 to January 31st 2014, six evaluable patients were recruited in ten hospitals of the Spanish Group for Transversal Oncology and Research in Orphan and Infrequent Tumors" (GETTHI). FOXL2 (402C > G) mutation was confirmed in three; two cases were wild type and it could not be assessed in one. No objective response by RECIST was observed, but five cases achieved stable disease longer than 12 months. Median progression-free survival was 14.06 months (CI 95% 5.43-22.69) for the whole study population (3.38 and 13.47 months for wild-type cases and 14.06, 20.67 and 26.51 for those with confirmed FOXL2 mutation). Median overall survival was 22·99 months (CI 95% 8.99-36.99). In vitro assays confirmed the activity of ketoconazole in this tumor and suggested potential synergisms with other hormone therapies.

CONCLUSION

Ketoconazole has shown activity in advanced GCT in clinical and in vitro studies. Based on these data, an orphan designation was granted by the European Medicines Agency for ketoconazole in GCT (EU/3/17/1857).

CLINICALTRIALS

GOV IDENTIFIER

NCT01584297.

A case series of triplet anti-hormonal therapy in androgen receptor-positive recurrent adult ovarian granulosa cell tumor

Therapeutic options for recurrent adult granulosa cell tumors (AGCT) are limited. After examining the hormonal pathways involved in FOXL2-mutated granulosa cell tumor development, a novel treatment regimen was utilized for recurrent AGCT: a combination of an androgen receptor antagonist, a gonadotropin-releasing hormone receptor agonist, and an aromatase inhibitor for hormonal blockade. In this case series, seven patients at our institution were treated with bicalutamide 50 mg orally once daily, Leuprolide acetate 7.5 mg intramuscular (IM) injection every 4 weeks, and a daily oral aromatase inhibitor. These patients had recurrent AGCT with androgen receptor positive tumors and had failed prior aromatase inhibitor therapy. All patients had undergone multiple surgical resections and many cycles of chemotherapy. Patients were monitored for toxicities and for response to treatment. Of the seven patients receiving the triple therapy, six saw clinical benefit. Two patients demonstrated a partial response and four patients had stable disease. One patient had progressive disease on the regimen. For the two patients who had a partial response to the triple therapy, there was strong expression of the androgen receptor (AR) noted on tumor immunohistochemistry. This drug combination was well-tolerated except for severe hot flashes in one patient. In conclusion, the triple therapy combination of an androgen receptor antagonist, aromatase inhibitor, and GnRH agonist demonstrated measurable responses in patients with recurrent AGCTs after multiple previous treatments. A prospective clinical trial is planned to further investigate these findings.

Molecular Pathways and Targeted Therapies for Malignant Ovarian Germ Cell Tumors and Sex Cord-Stromal Tumors: A Contemporary Review

Non-epithelial ovarian tumors are heterogeneous and account for approximately 10% of ovarian malignancies. The most common subtypes of non-epithelial ovarian tumors arise from germ cells or sex cord and stromal cells of the gonads. These tumors are usually detected at an early stage, and management includes surgical staging and debulking. When indicated for advanced disease, most respond to chemotherapy; however, options for patients with refractory disease are limited, and regimens can be associated with significant toxicities, including permanent organ dysfunction, secondary malignancies, and death. Targeted therapies that potentially decrease chemotherapy-related adverse effects and improve outcomes for patients with chemotherapy-refractory disease are needed. Here, we review the molecular landscape of non-epithelial ovarian tumors for the purpose of informing rational clinical trial design. Recent genomic discoveries have uncovered recurring somatic alterations and germline mutations in subtypes of non-epithelial ovarian tumors. Though there is a paucity of efficacy data on targeted therapies, such as kinase inhibitors, antibody–drug conjugates, immunotherapy, and hormonal therapy, exceptional responses to some compounds have been reported. The rarity and complexity of non-epithelial ovarian tumors warrant collaboration and efficient clinical trial design, including high-quality molecular characterization, to guide future efforts.

Adult Granulosa Cell Tumors of the Ovary: A Retrospective Study of 36 FIGO Stage I Cases with Emphasis on Prognostic Pathohistological Features

Objective

Adult granulosa cell tumors (AGCTs) represent 2%-5% of all ovarian malignancies. The aim of this study was to analyze clinical and pathohistological parameters and their impact on recurrence, overall, and disease-free survival in FIGO stage I AGCT patients.

Methods

The tumor specimens analyzed in this retrospective study were obtained from a total of 36 patients with diagnosis of ovarian AGCT surgically treated at the Department of Gynecology, Rijeka University Hospital Centre, between 1994 and 2012. Clinical, pathological, and follow-up data were collected.

Results

The mean age at diagnosis was 54.5 years with a range of 24-84. The majority of the patients, 30 (83%), were in FIGO stage IA, 3 (8%) in stage IC1, 1 (3%) in stage IC2, and 2 (6%) in stage IC3. During follow-up period (median 117.5 months, range 26-276), recurrence occurred in 4 patients (12%) with 2 deaths of the disease recorded. In univariate analysis, the 5-year survival rates were significantly shorter in patients with FIGO substage IC (p = 0.019), with positive LVSI (p = 0.022), with presence of necrosis (p = 0.040), and with hemorrhage (p = 0.017). In univariate analysis, the 5-year disease-free survival rates were significantly shorter in patients treated with fertility surgery (p = 0.004), with diffuse growth pattern (p = 0.012), with moderate and severe nuclear atypia (p = 0.032), and with presence of hemorrhage (p = 0.022). FIGO substage IC proved to be independent predictor for recurrence (OR = 16.87, p = 0.015, and OR = 23.49, p = 0.023, resp.) and disease-free survival (p = 0.0002; HR 20.84, p = 0.02) at the uni- and multivariate analyses.

Conclusions

FIGO substage IC is predictive of recurrence and disease-free survival in patients with early-stage AGCTs. LVSI, presence of necrosis and hemorrhage, diffuse growth pattern, and nuclear atypia in AGCTs seem to be associated with overall and disease-free survival, so these pathological features should be taken into consideration when managing patients with AGCT.

Ovarian adult-type granulosa cell tumor: focusing on endocrine-based therapies

Adult-type granulosa cell tumors (GCTs), although rare, are the most commonly diagnosed neoplasms arising in the endocrine-active ovarian stroma. They are characterized by excessive production of estrogens, antimullerian hormone and inhibins. In 2009, a specific mutation in FOXL2 was identified to be pathognomonic of GCTs. How dysregulation of this transcription factor, resulting in upregulation of aromatase, leads to unchecked proliferation, and progression to a malignancy, remains unclear. The key pathological and clinical feature of GCTs that affects their usually favorable outcomes is a diagnosis of greater than Stage 1 disease at presentation. Chemotherapy is given as adjuvant upon an advanced stage diagnosis; however, its effect on survival upon recurrence is modest. On the other hand, aromatase inhibitors also lead to tumor regression and are suitable for long-term maintenance.

Is adjuvant chemotherapy beneficial for patients with FIGO stage IC adult granulosa cell tumor of the ovary?

Background

To evaluate the association between adjuvant chemotherapy and clinical outcomes in patients with stage IC adult granulosa cell tumor (AGCT).

Methods

We performed a retrospective study of patients with stage IC AGCT diagnosed at our hospital from January 1985 to September 2015. We analyzed descriptive statistics, and performed univariate and multivariate and Kaplan–Meier survival analyses.

Results

Sixty stage IC AGCT patients were identified, including 28 in the no adjuvant chemotherapy group (NACG) and 32 in the adjuvant chemotherapy group (ACG). The median follow-up time was 88 months (range: 9–334 months). Sixteen patients developed recurrences, including nine in the NACG and seven in the ACG groups. Univariate analysis identified incomplete surgical staging and initial treatment place as associated with disease-free survival (DFS) (P = 0.003 and 0.038, respectively). Incomplete surgical staging remained a risk factor for recurrence in multivariate analysis (hazard ratio (HR) = 3.883, 95% confidence interval (CI): 1.123–13.430, P = 0.032). The 5-year DFS rates in the NACG and ACG groups were 76.3% and 87.5% respectively (P = 0.197). Adjuvant chemotherapy was thus not associated with improved DFS. Furthermore, the number of chemotherapy cycles was not associated with recurrence rate (≤3 cycles vs. > 3 cycles, HR = 0.613, 95% CI: 0.112–3.351, P = 0.572).

Conclusion

Administration of adjuvant chemotherapy does not improve DFS in patients with stage IC AGCT. Further studies with larger samples involving multi-institutional collaboration are needed to validate new treatment regimens for this disease.

Clinical and genetic analysis of recurrent adult-type granulosa cell tumor of the ovary: Persistent preservation of heterozygous c.402C>G FOXL2 mutation

BACKGROUND

Adult-type granulosa cell tumors of the ovary (aGCTs) are rare tumors that represent 2-5% of ovarian malignancies. The prognosis of this tumor is favorable, and it is characterized by slow progression. 10-30% of these tumors recur after 4-7 years of the primary surgery and the 5-year survival rate from the first recurrence is 55%, for the incompletely resected patients. At this time, complete resection is the only prognostic factor for better outcome, and establishing a novel strategy for identification and/or treatment of recurrent tumors is crucial. After the discovery of heterozygous c.402C>G FOXL2 mutations in 97% of cases of aGCT, much effort has been made to find the role of the mutation on the pathogenesis of aGCT, however, little is known about the role of the mutation in disease progression.

METHODS

We analyzed the clinical data of 56 aGCT patients to find a marker of recurrence. In particular, we compared the FOXL2 status in 5 matched primary and recurrent samples by immunohistochemistry, and TaqMan allelic discrimination assay to address the role of FOXL2 in potential mechanisms of recurrence.

RESULTS

The clinical data analysis was consistent with complete resection as an indicator of disease eradication, though the sample size was limited. The genetic analysis showed all the samples, including recurrent tumor samples up to 14 years after the primary surgery, expressed heterozygous c.402C>G FOXL2 mutation and the FOXL2 protein expression.

CONCLUSION

This report describes the preservation of heterozygous c.402C>G FOXL2 mutation in recurrent aGCTs. This finding adds further credence to the concept that the c.402C>G FOXL2 mutation is oncogenic and integral to this disease.

Upregulation of CYP17A1 by Sp1-mediated DNA demethylation confers temozolomide resistance through DHEA-mediated protection in glioma

Steroidogenesis-mediated production of neurosteroids is important for brain homeostasis. Cytochrome P450 17A1 (CYP17A1), which converts pregnenolone to dehydroepiandrosterone (DHEA) in endocrine organs and the brain, is required for prostate cancer progression and acquired chemotherapeutic resistance. However, whether CYP17A1-mediated DHEA synthesis is involved in brain tumor malignancy, especially in glioma, the most prevalent brain tumor, is unknown. To investigate the role of CYP17A1 in glioma, we determined that CYP17A1 expression is significantly increased in gliomas, which secrete more DHEA than normal astrocytes. We found that as gliomas became more malignant, both CYP17A1 and DHEA were significantly upregulated in temozolomide (TMZ)-resistant cells and highly invasive cells. In particular, the increase of CYP17A1 was caused by Sp1-mediated DNA demethylation, whereby Sp1 competed with DNMT3a for binding to the CYP17A1 promoter in TMZ-resistant glioma cells. CYP17A1 was required for the development of glioma cell invasiveness and resistance to TMZ-induced cytotoxicity. In addition, DHEA markedly attenuated TMZ-induced DNA damage and apoptosis. Together, our results suggest that components of the Sp1-CYP17A1-DHEA axis, which promotes the development of TMZ resistance, may serve as potential biomarkers and therapeutic targets in recurrent glioma.

A phase II study of paclitaxel for the treatment of ovarian stromal tumors: An NRG Oncology/ Gynecologic Oncology Group Study

OBJECTIVE

To estimate the probability of complete clinical response and toxicity of paclitaxel as second-line chemotherapy in measurable disease patients with malignant tumors of the ovarian stroma, and to evaluate the value of inhibin for predicting response.

METHODS

Thirty-one patients with histologically confirmed ovarian stromal tumor were enrolled from 2000 to 2013. Patients were required to have measurable recurrent disease, and to have received only one prior chemotherapy regimen. Paclitaxel 175 mg/m2 was administered over a 3 hour infusion, cycling every 21 days. Inhibin levels were drawn within two weeks of initiation of treatment.

RESULTS

Of 31 women enrolled, there was only one complete response (3.2%), and partial response in eight of 31 cases (25.8%). The pretreatment inhibin level for the single patient who had complete response was 88 pg/mL. Median progression-free survival was 10.0 months and overall survival was 73.6 months. Myelosuppression was common with 12 of 31 patients (38.7%) suffering grade 3 or 4 neutropenia, leukopenia, or anemia.

CONCLUSION

There were too few complete responses to warrant continued evaluation of paclitaxel as a single agent treatment for women with recurrent malignant ovarian stromal tumors with measurable disease according to the primary objective of the study. Toxicity of the regimen was acceptable. Pretreatment inhibin is not a reliable tumor marker as it was not elevated in the majority of patients.

Stage I granulosa cell tumours: A management conundrum? Results of long-term follow up

Optimal management of women with early stage granulosa cell tumours (GCT) presents a management conundrum - they have excellent prognosis but a third will relapse. Advances uncovering the molecular characteristics of GCT have not been matched by improvements in our understanding and treatment.

METHODS

Stage I GCT patients referred to Auckland City Hospital (1955-2012) and Princess Margaret Cancer Centre (1992-2012) were identified. Baseline characteristics, histopathology and outcomes were recorded retrospectively.

RESULTS

One hundred and sixty stage I GCT patients were identified with a median age of 49 years. Median follow-up was 7.0 years (range 0.1-44.2 years). Fifty-one patients (32%) relapsed with a median time to relapse (TTR) of 12.0 years (1.3-17.7 years) - 20 initial relapses occurred 10 years post-diagnosis. Higher relapse rates (43% vs. 24% p=0.02) and shorter TTR (10.2 vs. 16.2 years p=0.007) were seen with stage Ic versus stage Ia disease. Cyst rupture was associated with increased relapse (p=0.03). Surgery was the main therapeutic modality at relapse. Eighty six percent of patients received non-surgical management at least once post-relapse. Clinical benefit rate was 43% with chemotherapy, 61% with hormonal therapy and 86% with radiation. Five- and 10-year overall survival (OS) were 98.5 and 91.6%, respectively. Median OS was similar in patients with (24.3 years) and without relapse (22.3 years).

CONCLUSION

Surgery remains fundamental at diagnosis and relapse. Caution should be exercised in recommending adjuvant chemotherapy at initial diagnosis given median OS was greater than 20 years even with relapse. Hormonal therapy at relapse appears encouraging but needs further assessment. Novel treatment strategies need exploration with international collaboration essential for this.