Olaparib Addition to Maintenance Bevacizumab Therapy in Ovarian Carcinoma With BRCA-Like Genomic Aberrations.

Importance: Testing for homologous recombination deficiency is required for the optimal treatment of high-grade epithelial ovarian cancer. The search for accurate biomarkers is ongoing. Objective: To investigate whether progression-free survival (PFS) and overall survival (OS) of patients with high-grade epithelial ovarian cancer treated with maintenance olaparib or placebo differed between patients with a tumor BRCA-like genomic profile and patients without a tumor BRCA-like profile. Design, Setting, and Participants: This cohort study was a secondary analysis of the PAOLA-1 randomized clinical trial that compared olaparib plus bevacizumab with placebo plus bevacizumab as maintenance treatment in patients with advanced high-grade ovarian cancer after a good response to first-line platinum with taxane chemotherapy plus bevacizumab, irrespective of germline or tumor BRCA1/2 mutation status. All patients with available tumor DNA were included in the analysis. The current analysis tested for an interaction between BRCA-like status and olaparib treatment on survival outcomes. The original trial was conducted between July 2015 and September 2017; at the time of data extraction for analysis in March 2022, a median follow-up of 54.1 months (IQR, 28.5-62.2 months) and a total follow-up time of 21 711 months was available, with 336 PFS and 245 OS events. Exposures: Tumor homologous recombination deficiency was assessed using the BRCA-like copy number aberration profile classifier. Myriad MyChoice CDx was previously measured. The trial was randomized between the olaparib and bevacizumab and placebo plus bevacizumab groups. Main Outcomes and Measures: This secondary analysis assessed hazard ratios (HRs) of olaparib vs placebo among biomarker strata and tested for interaction between BRCA-like status and olaparib treatment on PFS and OS, using Cox proportional hazards regression. Results: A total of 469 patients (median age, 60 [range 26-80] years) were included in this study. The patient cohort consisted of women with International Federation of Gynaecology and Obstetrics stage III (76%) high-grade serous (95%) ovarian cancer who had no evaluable disease or complete remission at initial or interval debulking surgery (76%). Thirty-one percent of the tumor samples (n = 138) harbored a pathogenic BRCA mutation, and BRCA-like classification was performed for 442 patients. Patients with a BRCA-like tumor had a longer PFS after olaparib treatment than after placebo (36.4 vs 18.6 months; HR, 0.49; 95% CI, 0.37-0.65; P < .001). No association of olaparib with PFS was found in patients with a non-BRCA-like tumor (17.6 vs 16.6 months; HR, 1.02; 95% CI, 0.68-1.51; P = .93). The interaction was significant (P = .004), and HRs and P values (for interaction) were similar in the relevant subgroups, OS, and multivariable analyses. Conclusions and Relevance: In this secondary analysis of the PAOLA-1 randomized clinical trial, patients with a BRCA-like tumor, but not those with a non-BRCA-like tumor, had a significantly longer survival after olaparib plus bevacizumab treatment than placebo plus bevacizumab treatment. Thus, the BRCA1-like classifier could be used as a biomarker for olaparib plus bevacizumab as a maintenance treatment.

Dynamics of clonal hematopoiesis under DNA-damaging treatment in patients with ovarian cancer.

Clonal hematopoiesis (CH) driven by mutations in the DNA damage response (DDR) pathway is frequent in patients with cancer and is associated with a higher risk of therapy-related myeloid neoplasms (t-MNs). Here, we analyzed 423 serial whole blood and plasma samples from 103 patients with relapsed high-grade ovarian cancer receiving carboplatin, poly(ADP-ribose) polymerase inhibitor (PARPi) and heat shock protein 90 inhibitor (HSP90i) treatment within the phase II EUDARIO trial using error-corrected sequencing of 72 genes. DDR-driven CH was detected in 35% of patients and was associated with longer duration of prior PARPi treatment. TP53- and PPM1D-mutated clones exhibited substantially higher clonal expansion rates than DNMT3A- or TET2-mutated clones during treatment. Expansion of DDR clones correlated with HSP90i exposure across the three study arms and was partially abrogated by the presence of germline mutations related to homologous recombination deficiency. Single-cell DNA sequencing of selected samples revealed clonal exclusivity of DDR mutations, and identified DDR-mutated clones as the origin of t-MN in two investigated cases. Together, these results provide unique insights into the architecture and the preferential selection of DDR-mutated hematopoietic clones under intense DNA-damaging treatment. Specifically, PARPi and HSP90i therapies pose an independent risk for the expansion of DDR-CH in a dose-dependent manner.

Clinical evaluation of a low-coverage whole-genome test for detecting homologous recombination deficiency in ovarian cancer.

BACKGROUND: The PAOLA-1/ENGOT-ov25 trial showed that maintenance olaparib plus bevacizumab increases survival of advanced ovarian cancer patients with homologous recombination deficiency (HRD). However, decentralized solutions to test for HRD in clinical routine are scarce. The goal of this study was to retrospectively validate on tumor samples from the PAOLA-1 trial, the decentralized SeqOne assay, which relies on shallow Whole Genome Sequencing (sWGS) to capture genomic instability and targeted sequencing to determine BRCA status. METHODS: The study comprised 368 patients from the PAOLA-1 trial. The SeqOne assay was compared to the Myriad MyChoice HRD test (Myriad Genetics), and results were analyzed with respect to Progression-Free Survival (PFS). RESULTS: We found a 95% concordance between the HRD status of the two tests (95% Confidence Interval (CI); 92%-97%). The Positive Percentage Agreement (PPA) of the sWGS test was 95% (95% CI; 91%-97%) like its Negative Percentage Agreement (NPA) (95% CI; 89%-98%). In patients with HRD-positive tumors treated with olaparib plus bevacizumab, the PFS Hazard Ratio (HR) was 0.38 (95% CI; 0.26-0.54) with SeqOne assay and 0.32 (95% CI; 0.22-0.45) with the Myriad assay. In patients with HRD-negative tumors, HR was 0.99 (95% CI; 0.68-1.42) and 1.05 (95% CI; 0.70-1.57) with SeqOne and Myriad assays. Among patients with BRCA-wildtype tumors, those with HRD-positive tumors, benefited from olaparib plus bevacizumab maintenance, with HR of 0.48 (95% CI: 0.29-0.79) and of 0.38 (95% CI: 0.23 to 0.63) with the SeqOne and Myriad assay. CONCLUSION: The SeqOne assay offers a clinically validated approach to detect HRD.

BRCA1/2 alterations and reversion mutations in the area of PARP inhibitors in high grade ovarian cancer: state of the art and forthcoming challenges.

BRCA1/2 genes are part of homologous recombination (HR) DNA repair pathways in charge of error-free double-strand break (DSB) repair. Loss-of-function mutations of BRCA1/2 genes have been associated for a long time with breast and ovarian cancer hereditary syndrome. Recently, polyadenosine diphosphate-ribose polymerase inhibitors (PARPi) have revolutionized the therapeutic landscape of BRCA1/2-mutated tumors, especially of BRCA1/2 high-grade serous ovarian cancer (HGSC), taking advantage of HR deficiency through the synthetic lethality concept. However, PARPi efficiency differs among patients, and most of them will develop resistance, particularly in the relapse setting. In the current proposal, we aim to review primary and secondary resistance to PARPi in HGSC owing to BRCA1/2 alterations. Of note, as several mechanisms of primary or secondary resistance to PARPi have been described, BRCA1/2 reversion mutations that restore HR pathways are by far the most reported. First, the type and location of the BRCA1/2 primary mutation have been associated with PARPi and platinum-salt sensitivity and impact the probability of the occurrence and the type of secondary reversion mutation. Furthermore, the presence of multiple reversion mutations and the variation of allelic frequency under treatment underline the role of intratumor heterogeneity (ITH) in treatment resistance. Of note, circulating tumor DNA might help us to detect and characterize reversion mutations and ITH to finally refine the treatment strategy. Importantly, forthcoming therapeutic strategies, including combination with antiangiogenics or with targeted therapies, may help us delay and overcome PARPi resistance secondary to BRCA1/2 reversion mutations. Also, progression despite PARPi therapy does not preclude PARPi rechallenge in selected patients.

Management of patients with rare adult solid cancers: objectives and evaluation of European reference networks (ERN) EURACAN.

About 500,000 patients with rare adult solid cancers (RASC) are diagnosed yearly in Europe. Delays and unequal quality of management impact negatively their survival. Since 2017, European reference networks (ERN) aim to improve the quality of care of patients with rare disease. The steering committee of EURACAN, including physicians, researchers and patients review here the previous actions, present objectives of the ERN EURACAN dedicated to RASC. EURACAN promoted management in reference centres, and equal implementation of excellence and innovation in Europe and developed 22 clinical practice guidelines (CPGs). Additionally, fourteen information brochures translated in 24 EU languages were developed in collaboration with patient advocacy groups (ePAGs) and seventeen training session were organized. Nevertheless, connections to national networks in the 26 participating countries (106 centres), simplification of cross-border healthcare, international multidisciplinary tumour boards, registries and monitoring of the quality of care are still required. In this Health Policy, evaluation criteria of the performances of the network and of health care providers are proposed.

Atezolizumab plus bevacizumab and chemotherapy for metastatic, persistent, or recurrent cervical cancer (BEATcc): a randomised, open-label, phase 3 trial.

BACKGROUND: The GOG240 trial established bevacizumab with chemotherapy as standard first-line therapy for metastatic or recurrent cervical cancer. In the BEATcc trial (ENGOT-Cx10-GEICO 68-C-JGOG1084-GOG-3030), we aimed to evaluate the addition of an immune checkpoint inhibitor to this standard backbone. METHODS: In this investigator-initiated, randomised, open-label, phase 3 trial, patients from 92 sites in Europe, Japan, and the USA with metastatic (stage IVB), persistent, or recurrent cervical cancer that was measurable, previously untreated, and not amenable to curative surgery or radiation were randomly assigned 1:1 to receive standard therapy (cisplatin 50 mg/m2 or carboplatin area under the curve of 5, paclitaxel 175 mg/m2, and bevacizumab 15 mg/kg, all on day 1 of every 3-week cycle) with or without atezolizumab 1200 mg. Treatment was continued until disease progression, unacceptable toxicity, patient withdrawal, or death. Stratification factors were previous concomitant chemoradiation (yes vs no), histology (squamous cell carcinoma vs adenocarcinoma including adenosquamous carcinoma), and platinum backbone (cisplatin vs carboplatin). Dual primary endpoints were investigator-assessed progression-free survival according to Response Evaluation Criteria in Solid Tumours version 1.1 and overall survival analysed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03556839, and is ongoing. FINDINGS: Between Oct 8, 2018, and Aug 20, 2021, 410 of 519 patients assessed for eligibility were enrolled. Median progression-free survival was 13·7 months (95% CI 12·3-16·6) with atezolizumab and 10·4 months (9·7-11·7) with standard therapy (hazard ratio [HR]=0·62 [95% CI 0·49-0·78]; p<0·0001); at the interim overall survival analysis, median overall survival was 32·1 months (95% CI 25·3-36·8) versus 22·8 months (20·3-28·0), respectively (HR 0·68 [95% CI 0·52-0·88]; p=0·0046). Grade 3 or worse adverse events occurred in 79% of patients in the experimental group and in 75% of patients in the standard group. Grade 1-2 diarrhoea, arthralgia, pyrexia, and rash were increased with atezolizumab. INTERPRETATION: Adding atezolizumab to a standard bevacizumab plus platinum regimen for metastatic, persistent, or recurrent cervical cancer significantly improves progression-free and overall survival and should be considered as a new first-line therapy option. FUNDING: F Hoffmann-La Roche.

Role of gene sequencing in classifying struma ovarii: BRAF p.G469A mutation and TERT promoter alterations favour malignant struma ovarii.

AIMS: Struma ovarii (SO) are rare, accounting for 0.3-1% of ovarian tumours, and include benign and malignant lesions. In most cases, histology is not predictive of clinical outcome and prognosis. The prognosis of histologically malignant thyroid-type carcinomas can indeed be excellent, while SO, composed of normal thyroid tissue, can recur and are designated highly differentiated follicular carcinoma of the ovary. Clearer diagnostic criteria are therefore required. METHODS AND RESULTS: We retrospectively studied 31 SO using DNA and RNA sequencing with pan-cancer gene panels, including eight biologically malignant SO (BMSO) defined based on ovarian serosal or extra-ovarian dissemination at presentation or during follow-up, 10 stage IA histologically malignant SO (HMSO) with thyroid-type carcinoma morphology and 13 biologically and histologically benign SO (BSO), with none of the above-mentioned characteristics. Molecular alterations were observed in 87.5% of BMSO, 70% of HMSO and 7.7% of BSO (P < 0.001). All patients with a peritoneal dissemination at presentation or during follow-up had at least one gene alteration. BRAF mutations (44.5%) were only observed in malignant forms (HMSO and BMSO) and TERT promoter alterations (25%) only in cases of BMSO. The BRAF p.G469A mutation, which is extremely rare in thyroid carcinomas, was the molecular alteration most frequently associated with malignant SO (28.5%). CONCLUSION: Our results highlight the clinical utility of molecular sequencing in SO, based on this limited number of cases. However, as malignant SO evolve slowly, more extensive molecular studies in SO with more than 10 years' follow-up are required to draw any conclusions on the prognostic value of the associated gene alterations.

[Diagnosis of uterine sarcomas and rare uterine mesenchymal tumours with malignant potential. Guidelines of the French Sarcoma Group and Rare Gynaecological Tumours]. / Diagnostic des sarcomes utérins et tumeurs mésenchymateuses utérines rares à potentiel de malignité. Référentiels du Groupe Sarcome Français et des Tumeurs Rares Gynécologiques.

The landscape of uterine sarcomas is becoming more complex with the description of new entities associated with recurrent driver molecular alterations. Uterine sarcomas, in analogy with soft tissue sarcomas, are distinguished into complex genomic and simple genomic sarcomas. Leiomyosarcomas and undifferentiated uterine sarcomas belong to complex genomic sarcomas group. Low-grade and high-grade endometrial stromal sarcomas, other rare tumors associated with fusion transcripts (such as NTRK, PDGFB, ALK, RET ROS1) and SMARCA4-deficient uterine sarcoma are considered simple genomic sarcomas. The most common uterine sarcoma are first leiomyosarcoma and secondly endometrial stromal sarcomas. Three different histological subtypes of leiomyosarcoma (fusiform, myxoid, epithelioid) are identified, myxoid and epithelioid leiomyosarcoma being more aggressive than fusiform leiomyosarcoma. The distinction between low-grade and high-grade endometrial stromal sarcoma is primarily morphological and immunohistochemical and the detection of fusion transcripts can help the diagnosis. Uterine PEComa is a rare tumor, which is distinguished into borderline and malignant, according to a risk assessment algorithm. Embryonal rhabdomyosarcoma of the uterine cervix is more common in children but can also occur in adult women. Embryonal rhabdomyosarcoma of the uterine cervix is almost always DICER1 mutated, unlike that of the vagina which is wild-type DICER1, and adenosarcoma which can be DICER1 mutated but with less frequency. Among the emerging entities, sarcomas associated with fusion transcripts involving the NTRK, ALK, PDGFB genes benefit from targeted therapy. The integration of molecular data with histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Mirvetuximab soravtansine-gynx: first antibody/antigen-drug conjugate (ADC) in advanced or recurrent ovarian cancer.

Mirvetuximab soravtansine-gynx (MIRV) is a conjugate of a folate receptor alpha (FRα)-directed antibody and the maytansinoid microtubule inhibitor, DM4. Accumulating pre-clinical and clinical data supported the safety and anti-tumor activity of MIRV in tumors expressing FRα. In 2017, a phase I expansion study reported the first experience of MIRV in FRα-positive platinum-resistant ovarian cancer with promising results. However, the phase III FORWARD I study failed to demonstrate a significant benefit of MIRV in FRα-positive tumors. On the basis of the data reported from this latter study, MIRV was then explored in the FRα-high population only and using a different folate receptor assay. The phase II SORAYA trial supported the adoption of MIRV in this setting. Hence, the US Food and Drug Administration granted accelerated approval of MIRV for patients with FRα-positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1-3 prior systemic treatment regimens. Moreover, the results of the MIRASOL trial showed a significant reduction in the risk of tumor progression or death among patients treated with MIRV versus chemotherapy. VENTANA FOLR1 (FOLR-2.1) was approved as a companion diagnostic test to identify FRα patients. MIRV appears to be a significant asset in managing advanced or recurrent ovarian cancer. Further trials are needed to confirm these promising results, even in the neoadjuvant, adjuvant, and maintenance settings.

Updated progression-free survival and final overall survival with maintenance olaparib plus bevacizumab according to clinical risk in patients with newly diagnosed advanced ovarian cancer in the phase III PAOLA-1/ENGOT-ov25 trial.

OBJECTIVE: In the PAOLA-1/ENGOT-ov25 trial (NCT02477644), adding maintenance olaparib to bevacizumab provided a substantial progression-free survival benefit in patients with newly diagnosed advanced ovarian cancer and homologous recombination deficiency (HRD)-positive tumors, irrespective of clinical risk. Subsequently, a clinically meaningful improvement in overall survival was reported with olaparib plus bevacizumab in the HRD-positive subgroup. We report updated progression-free survival and overall survival by clinical risk and HRD status. METHODS: Patients in clinical response after first-line platinum-based chemotherapy plus bevacizumab received maintenance olaparib (up to 24 months) plus bevacizumab (up to 15 months in total) or placebo plus bevacizumab. This post hoc analysis evaluated 5-year progression-free survival and mature overall survival in patients classified by clinical risk and HRD status. RESULTS: Of 806 randomized patients, 74% were higher-risk and 26% were lower-risk. In higher-risk HRD-positive patients, the hazard ratio (HR) for progression-free survival was 0.46 (95% confidence interval (95% CI) 0.34 to 0.61), with 5-year progression-free survival of 35% with olaparib plus bevacizumab versus 15% with bevacizumab alone; and the HR for overall survival was 0.70 (95% CI 0.50 to 1.00), with 5-year overall survival of 55% versus 42%, respectively. In lower-risk HRD-positive patients, the HR for progression-free survival was 0.26 (95% CI 0.15 to 0.45), with 5-year progression-free survival of 72% with olaparib plus bevacizumab versus 28% with bevacizumab alone; and the HR for overall survival was 0.31 (95% CI 0.14 to 0.66), with 5-year overall survival of 88% versus 61%, respectively. No benefit was seen in HRD-negative patients regardless of clinical risk. CONCLUSION: This post hoc analysis indicates that in patients with newly diagnosed advanced HRD-positive ovarian cancer, maintenance olaparib plus bevacizumab should not be limited to those considered at higher risk of disease progression. Five-year progression-free survival rates support long-term remission and suggest an increased potential for cure with particular benefit suggested in lower-risk HRD-positive patients.

GIInger predicts homologous recombination deficiency and patient response to PARPi treatment from shallow genomic profiles.

Homologous recombination deficiency (HRD) is a predictive biomarker for poly(ADP-ribose) polymerase 1 inhibitor (PARPi) sensitivity. Routine HRD testing relies on identifying BRCA mutations, but additional HRD-positive patients can be identified by measuring genomic instability (GI), a consequence of HRD. However, the cost and complexity of available solutions hamper GI testing. We introduce a deep learning framework, GIInger, that identifies GI from HRD-induced scarring observed in low-pass whole-genome sequencing data. GIInger seamlessly integrates into standard BRCA testing workflows and yields reproducible results concordant with a reference method in a multisite study of 327 ovarian cancer samples. Applied to a BRCA wild-type enriched subgroup of 195 PAOLA-1 clinical trial patients, GIInger identified HRD-positive patients who experienced significantly extended progression-free survival when treated with PARPi. GIInger is, therefore, a cost-effective and easy-to-implement method for accurately stratifying patients with ovarian cancer for first-line PARPi treatment.

Shallow whole genome sequencing approach to detect Homologous Recombination Deficiency in the PAOLA-1/ENGOT-OV25 phase-III trial.

The bevacizumab (bev)/olaparib (ola) maintenance regimen was approved for BRCA1/2-mutated (BRCAmut) and Homologous Recombination Deficient (HRD) high-grade Advanced Ovarian Cancer (AOC) first line setting, based on a significantly improved progression-free survival (PFS) compared to bev alone in the PAOLA-1/ENGOT-ov25 trial (NCT02477644), where HRD was detected by MyChoice CDx PLUS test. The academic shallowHRDv2 test was developed based on shallow whole-genome sequencing as an alternative to MyChoice. Analytical and clinical validities of shallowHRDv2 as compared to MyChoice on 449 PAOLA-1 tumor samples are presented. The overall agreement between shallowHRDv2 and MyChoice was 94% (369/394). Less non-contributive tests were observed with shallowHRDv2 (15/449; 3%) than with MyChoice (51/449; 11%). Patients with HRD tumors according to shallowHRDv2 (including BRCAmut) showed a significantly prolonged PFS with bev+ola versus bev (median PFS: 65.7 versus 20.3 months, hazard ratio (HR): 0.36 [95% CI: 0.24-0.53]). This benefit was significant also for BRCA1/2 wild-type tumors (40.8 versus 19.5 months, HR: 0.45 [95% CI: 0.26-0.76]). ShallowHRDv2 is a performant, clinically validated, and cost-effective test for HRD detection.

The promise of combining CDK4/6 inhibition with hormonal therapy in the first-line treatment setting for metastatic or recurrent endometrial adenocarcinoma.

Metastatic or recurrent endometrioid adenocarcinoma of the uterine corpus is often incurable with limited treatment options. First-line treatment often includes cytotoxic chemotherapy, which incurs significant toxicities for many patients. Endometrial cancer, specifically endometrioid cancer, is a hormone-sensitive disease and, while single-agent hormonal therapies have demonstrated clinical benefit, resistance to these agents often leads to the use of chemotherapy. There is a lack of approved endocrine treatment options in the metastatic setting for most recurrent endometrial cancers, representing an unmet clinical need. Emerging evidence suggests that hormonal therapy in combination with other targeted treatments, such as cyclin dependent kinase (CDK)4/6 inhibitors, is well tolerated and effective in select patient populations. We discuss the clinical evidence suggesting that the combination of CDK4/6 inhibitors and hormonal therapy has the potential to represent an important addition to the first-line treatment options for patients with low-grade advanced or recurrent endometrial cancer.

European multidisciplinary tumor boards support cross-border networking and increase treatment options for patients with rare gynecological tumors.

OBJECTIVE: To evaluate outcomes of European cross-border multidisciplinary tumor boards in terms of participation, adherence to treatment recommendations, and access to novel treatment strategies. METHODS: The European reference network for rare gynecological tumors (EURACAN G2 domain) aims to improve the diagnosis, management, and treatment of patients with these cancers. Cross-border multidisciplinary tumor boards were initiated to facilitate intercollegiate clinical discussions across Europe and increase patients' access to specialist treatment recommendations and clinical trials. All G2 healthcare providers were invited to participate in monthly multidisciplinary meetings. Patient data were collected using a standardized form and case summaries were distributed before each meeting. After each tumor board, a meeting summary with treatment recommendations was sent to all participants and the project manager at the coordinating center. The multidisciplinary tumor board format and outcomes were regularly discussed at G2 domain meetings. Anonymized clinical data and treatment recommendations were registered in a prospective database. For this report, clinical data were collected between November 2017 and December 2020 and follow-up data retrieved until May 2021. RESULTS: During the 3-year period, 31 multidisciplinary tumor boards were held with participants from 10 countries and 20 centers. 91 individual patients were discussed between one and six times for a total of 109 case discussions. Follow-up data were retrieved from 64 patients and 80 case discussions. Adherence to treatment recommendations was 99%. Multidisciplinary tumor board recommendations resulted in 11 patients getting access to off-label treatment and one patient being enrolled in a clinical trial in another European country. 14/91 patients were recommended for surveillance only when additional treatment had been considered locally. CONCLUSION: Cross-border multidisciplinary tumor boards enable networking and clinical collaboration between healthcare professionals in different countries. Surveillance strategies, off-label drug use, and increased participation in clinical trials are possible benefits to patients with rare gynecological tumors.

Gynecological carcinosarcomas: Overview and future perspectives.

Gynecologic carcinosarcoma (CS) are rare and aggressive tumors composed of high-grade carcinoma and sarcoma. Carcinosarcoma account for less than 5% of uterine and ovarian carcinoma and patients have poor outcome with a 5-year overall survival of less than 30%. In early-stage setting, the treatment mainstay is surgery and adjuvant chemoradiotherapy or adjuvant chemotherapy in uterine (UCS) and ovarian CS (OCS), respectively. In metastatic or advanced stage disease, chemotherapy is the rule with a lower response rate and poorer prognosis compared to other high-grade carcinomas. Although very few treatment options are available, CS are often excluded from the clinical trials precluding therapeutic improvement. However, recent molecular advances are paving the way for new therapeutic strategies. In the current proposal, we extensively review the uterine and ovarian carcinosarcomas including epidemiology, pathology, genomic landscape, as well as current therapies and future perspectives.

Validation of the Clinical Use of GIScar, an Academic-developed Genomic Instability Score Predicting Sensitivity to Maintenance Olaparib for Ovarian Cancer.

PURPOSE: The optimal application of maintenance PARP inhibitor therapy for ovarian cancer requires accessible, robust, and rapid testing of homologous recombination deficiency (HRD). However, in many countries, access to HRD testing is problematic and the failure rate is high. We developed an academic HRD test to support treatment decision-making. EXPERIMENTAL DESIGN: Genomic Instability Scar (GIScar) was developed through targeted sequencing of a 127-gene panel to determine HRD status. GIScar was trained from a noninterventional study with 250 prospectively collected ovarian tumor samples. GIScar was validated on 469 DNA tumor samples from the PAOLA-1 trial evaluating maintenance olaparib for newly diagnosed ovarian cancer, and its predictive value was compared with Myriad Genetics MyChoice (MGMC). RESULTS: GIScar showed significant correlation with MGMC HRD classification (kappa statistics: 0.780). From PAOLA-1 samples, more HRD-positive tumors were identified by GIScar (258) than MGMC (242), with a lower proportion of inconclusive results (1% vs. 9%, respectively). The HRs for progression-free survival (PFS) with olaparib versus placebo were 0.45 [95% confidence interval (CI), 0.33-0.62] in GIScar-identified HRD-positive BRCA-mutated tumors, 0.50 (95% CI, 0.31-0.80) in HRD-positive BRCA-wild-type tumors, and 1.02 (95% CI, 0.74-1.40) in HRD-negative tumors. Tumors identified as HRD positive by GIScar but HRD negative by MGMC had better PFS with olaparib (HR, 0.23; 95% CI, 0.07-0.72). CONCLUSIONS: GIScar is a valuable diagnostic tool, reliably detecting HRD and predicting sensitivity to olaparib for ovarian cancer. GIScar showed high analytic concordance with MGMC test and fewer inconclusive results. GIScar is easily implemented into diagnostic laboratories with a rapid turnaround.

Gestational choriocarcinoma.

Gestational choriocarcinoma accounts for 5% of gestational trophoblastic neoplasms. Approximately 50%, 25%, and 25% of gestational choriocarcinoma occur after molar pregnancies, term pregnancies, and other gestational events, respectively. The FIGO scoring system categorizes patients into low (score 0 to 6) and high risk (score 7 or more) choriocarcinoma. Single-agent and multi-agent chemotherapy are used in low- and high-risk patients, respectively. Chemotherapy for localized disease has a goal of eradication of disease without surgery and is associated with favorable prognosis and fertility preservation. Most patients with gestational choriocarcinoma are cured with chemotherapy; however, some (<5.0%) will die as a result of multi-drug resistance, underscoring the need for novel approaches in this group of patients. Although there are limited data due to its rarity, the treatment response with immunotherapy is high, ranging between 50-70%. Novel combinations of immune checkpoint inhibitors with targeted therapies (including VEGFR-2 inhibitors) are under evaluation. PD-L1 inhibitors are considered a potential important opportunity for chemo-resistant patients, and to replace or de-escalate chemotherapy to avoid or minimize chemotherapy toxicity. In this review, the Rare Tumor Working Group and the European Organization for Research and Treatment of Cancer evaluated the current landscape and further perspective in the management of patients diagnosed with gestational choriocarcinoma.

Low-Grade Uterine Leiomyosarcoma Is Highly Sensitive to Hormonal Treatment.

PURPOSE: According to the World Health Organization classification system, uterine leiomyosarcomas (ULMS) are high-grade. A diagnosis of smooth-muscle tumors of uncertain malignant potential (STUMP) is made when Stanford Criteria for ULMS are not met. When a STUMP recurs, the tumor is diagnosed as ULMS and medical treatment is the same as for ULMS. In recent years, some sarcoma centers valued the less aggressive clinical behavior of several recurring STUMP and, given their expression of estrogen and progesterone receptors, started to treat them with hormonal therapy. EXPERIMENTAL DESIGN: This was a retrospective cohort analysis conducted at three referral centers joining the Leiomyosarcoma Foundation Roundtable. We selected all cases of uterine smooth muscle tumors consistent with STUMP and treated with hormonal therapy. RESULTS: 27 consecutive patients were identified. Median age at diagnosis was 43 years. Stage was IA-IB in more than 70% of patients. In these patients, median time to relapse was 62 months. Sites of first relapses were mostly pelvis and peritoneum (76%). After a median follow-up of 49 months, 14 patients (52%) had a partial response while 10 (37%) had a minor response or stable disease. Median time to progression was not reached. CONCLUSIONS: We observed a response or long-term stability rate on hormonal therapy in the 90% range; in all cases the time to relapse was significantly longer than in ULMS and in most cases the relapse was abdominal. On the basis of these findings, we conclude that a proportion of patients with uterine smooth muscle neoplasms actually present with a "low-grade ULMS."

Netrin-1 blockade inhibits tumor associated Myeloid-derived suppressor cells, cancer stemness and alleviates resistance to chemotherapy and immune checkpoint inhibitor.

Drug resistance and cancer relapse represent significant therapeutic challenges after chemotherapy or immunotherapy, and a major limiting factor for long-term cancer survival. Netrin-1 was initially identified as a neuronal navigation cue but has more recently emerged as an interesting target for cancer therapy, which is currently clinically investigated. We show here that netrin-1 is an independent prognostic marker for clinical progression of breast and ovary cancers. Cancer stem cells (CSCs)/Tumor initiating cells (TICs) are hypothesized to be involved in clinical progression, tumor relapse and resistance. We found a significant correlation between netrin-1 expression and cancer stem cell (CSC) markers levels. We also show in different mice models of resistance to chemotherapies that netrin-1 interference using a therapeutic netrin-1 blocking antibody alleviates resistance to chemotherapy and triggers an efficient delay in tumor relapse and this effect is associated with CSCs loss. We also demonstrate that netrin-1 interference limits tumor resistance to immune checkpoint inhibitor and provide evidence linking this enhanced anti-tumor efficacy to a decreased recruitment of a subtype of myeloid-derived suppressor cells (MDSCs) called polymorphonuclear (PMN)-MDSCs. We have functionally demonstrated that these immune cells promote CSCs features and, consequently, resistance to anti-cancer treatments. Together, these data support the view of both a direct and indirect contribution of netrin-1 to cancer stemness and we propose that this may lead to therapeutic opportunities by combining conventional chemotherapies and immunotherapies with netrin-1 interfering drugs.