Tatsuyuki Chiyoda

High-Throughput Drug Screening of Clear Cell Ovarian Cancer Organoids Reveals Vulnerability to Proteasome Inhibitors and Dinaciclib and Identifies AGR2 as a Therapeutic Target

Abstract There are currently no effective treatments available for clear cell ovarian cancer (CCC). In this study, we aimed to identify effective drugs for CCC through high-throughput drug screening (HTDS) using ovarian cancer organoids and determine novel therapeutic targets based on the biological characteristics of CCC through omics analysis. An ovarian cancer organoid biobank was established, and HTDS was conducted using CCC organoids based on libraries of 361 and 4,560 compounds. The efficacy of the identified drugs was verified in in vitro and in vivo experiments using a patient-derived organoid xenograft mouse model. Transcriptome analysis was performed to identify genes related to the pathways targeted by the identified drugs in CCC and to assess their potential as therapeutic targets. Proteasome inhibitors and dinaciclib were extracted using HTDS and shown to inhibit tumorigenesis in vitro and in vivo. CCC, like multiple myeloma, exhibited activated endoplasmic reticulum (ER) stress and unfolded protein response (UPR), and treatment with proteasome inhibitors further enhanced ER stress and UPR, ultimately leading to cell death. Transcriptome analysis identified anterior gradient-2 (AGR2) as a key gene involved in UPR in CCC. CRISPR knockout of AGR2 suppressed cell proliferation, increased sensitivity to proteasome inhibitors, and reversed platinum resistance in CCC. AGR2 knockout also upregulated Schlafen 11, contributing to platinum sensitivity. ER stress and the UPR are activated in CCC, and proteasome inhibitors disrupt this balance, ultimately leading to cell death. AGR2 may serve as a potential therapeutic target in CCC. Significance: Proteasome inhibitors and dinaciclib are identified as effective drugs for CCC. CCC has a high basal UPR, and proteasome inhibition may disrupt this balance. AGR2 is involved in the UPR of CCC, and inhibiting AGR2 further enhances the UPR and confers platinum sensitivity, making it a potential therapeutic target.

Characteristics of endometrial cancer progressed to extrauterine lesions following fertility preserving medroxyprogesterone acetate therapy for young endometrial cancer patients

Medroxyprogesterone acetate (MPA) is an effective fertility-preserving treatment for early endometrial cancer and atypical endometrial hyperplasia (AEH), and rarely leads to the development of extrauterine lesions (ELs). We aimed to clarify the characteristics of patients who developed ELs post-MPA therapy. We analyzed the clinicopathological factors and prognoses of 319 patients with endometrioid carcinoma grade 1 (EMG1) and AEH treated with MPA at our institution. All patients underwent imaging before MPA treatment to rule out ELs. Seven patients (2.2%) with EMG1 showed EL after MPA treatment. Two patients developed EL during the initial treatment, 2 during repeated treatment, and 3 during follow-up. Two patients had peritoneal dissemination, 3 had regional lymph node metastasis, 1 had distant metastasis at the Virchow lymph node, and 1 had ovarian metastasis. ELs were diagnosed using imaging tests in 6 patients and elevated tumor markers in 3 (overlapping) patients. One patient was diagnosed with ELs pathologically after hysterectomy. Upon EL diagnosis, patients underwent standard treatment, including hysterectomy and chemotherapy, that was followed by a diagnosis of EMG1 for 5, EMG2 for 1, and EMG3 for 1 patient. One patient died 15 months after start of therapy and another died 119 months post-treatment initiation, while the others have been survived. Only 2.2% of all patients developed ELs post-MPA treatment, but some cases were fatal. It is essential to conduct imaging tests and screen for tumor markers during and after MPA treatment regularly and also when cancer progression is suspected.

mTOR-mediated p62/SQSTM1 stabilization confers a robust survival mechanism for ovarian cancer

Over 50 % of patients with high-grade serous carcinoma (HGSC) are homologous recombination proficient, making them refractory to platinum-based drugs and poly (ADP-ribose) polymerase (PARP) inhibitors. These patients often develop progressive resistance within 6 months after primary treatment and tend to die early, thus new therapies are urgently needed. In this study, we comprehensively investigated this tumor type by leveraging a combination of machine learning analysis of a large published dataset and newly developed genetically engineered HGSC organoid models from murine fallopian tubes. Aberrant activation of RAS/PI3K signaling was a signature of poor prognosis in BRCA1/2 wild-type ovarian cancer, and mTOR-induced elevated p62 expression was a robust marker of chemotherapy-induced mTOR-p62-NRF2 signal activation. mTOR inhibition with everolimus decreased p62 and enhanced sensitivity to conventional chemotherapy, indicating that p62 serves as an important biomarker for therapeutic intervention. Combination therapy with conventional chemotherapy and mTOR inhibitors is a promising therapeutic strategy for refractory HGSC, with p62 as a biomarker.

Transcriptome Concordance Between Borderline Tumors and Endometrioid Carcinoma: An Integrative Genomic Analysis

ABSTRACTBackgroundBorderline ovarian tumors (BOTs) differ from ovarian carcinomas in their clinical presentation and behavior, yet their molecular characteristics remain poorly understood. This study aims to address this gap by integrating whole‐exome sequencing (WES) and RNA sequencing (RNA‐seq) to compare BOTs with high‐grade serous carcinoma (HGSC), endometrioid carcinoma (EC), and clear‐cell carcinoma (CCC).ObjectiveTo elucidate the molecular features of BOTs and evaluate their similarities and differences in comparison to HGSC, EC, and CCC.MethodsThe study analyzed 44 ovarian tumor samples, employing WES to identify genomic alterations and RNA‐seq to examine transcriptomic profiles. Comparative analyses were conducted to investigate the molecular relationships among the tumor types.ResultsThe genomic analysis revealed that BOTs share significant similarities with EC. Furthermore, the transcriptomic data highlighted a novel and substantial similarity between BOTs and EC, suggesting deeper biological linkages, including potentially shared oncogenic pathways or tumor microenvironmental factors. These findings challenge traditional classifications and suggest a closer molecular alignment of BOTs with EC than previously understood.ConclusionsThis study provides new insights into the molecular characteristics of BOTs, demonstrating their significant resemblance to EC at both the genomic and transcriptomic levels. These results underscore the potential need to reconsider the molecular classification of ovarian tumors and open new avenues for research into the pathogenesis and treatment strategies for BOTs.

BRCA1/2 reversion mutations in a pan‐cancer cohort

AbstractTumor sensitivity to platinum (Pt)‐based chemotherapy and poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors is increased by homologous recombination deficiency‐causing mutations; in particular, reversion mutations cause drug resistance by restoring protein function. Treatment response is predicted by breast cancer susceptibility gene 1/2 (BRCA1/2) mutations; however, BRCA1/2 reversion mutations have not been comprehensively studied in pan‐cancer cohorts. We aimed to characterize BRCA1/2 reversion mutations in a large pan‐cancer cohort of Japanese patients by retrospectively analyzing sequencing data for BRCA1/2 pathogenic/likely pathogenic mutations in 3738 patients with 32 cancer types. We identified somatic mutations in tumors or circulating cell‐free DNA that could restore the ORF of adverse alleles, including reversion mutations. We identified 12 (0.32%) patients with somatic BRCA1 (n = 3) and BRCA2 (n = 9) reversion mutations in breast (n = 4), ovarian/fallopian tube/peritoneal (n = 4), pancreatic (n = 2), prostate (n = 1), and gallbladder (n = 1) cancers. We identified 21 reversion events—BRCA1 (n = 3), BRCA2 (n = 18)—including eight pure deletions, one single‐nucleotide variant, six multinucleotide variants, and six deletion–insertions. Seven (33.3%) reversion deletions showed a microhomology length greater than 1 bp, suggesting microhomology‐mediated end‐join repair. Disease course data were obtained for all patients with reversion events: four patients acquired mutations after PARP‐inhibitor treatment failure, two showed somatic reversion mutations after disease progression, following Pt‐based treatment, five showed mutations after both treatments, one patient with pancreatic cancer and BRCA1 reversion mutations had no history of either treatment. Although reversion mutations commonly occur in BRCA‐associated cancers, our findings suggest that reversion mutations due to Pt‐chemotherapy might be correlated with BRCA1/2‐mediated tumorigenesis even in non‐BRCA‐associated histologies.

CXCL9 and CXCL13 shape endometrial cancer immune‐activated microenvironment via tertiary lymphoid structure formation

AbstractImmune checkpoint inhibitor (ICI) therapy has been successfully applied to various cancers; however, not all patients respond to ICI therapy. Tumors with an immune‐activated environment are highly responsive to ICIs. To identify the cells and molecules essential to the formation of an immune‐activated cancer microenvironment, we focused on the tertiary lymphoid structure (TLS) and performed histological and genomic analyses using endometrial cancer material. In the high immunogenic group, numerous TLSs were observed, and CXCL9 and CXCL13 expression was markedly increased. CXCL9‐positive antigen‐presenting and CXCL13‐positive follicular dendritic cells were distributed in the T‐ and B‐cell zones of TLSs, respectively. A group of molecules whose expression was upregulated along with CXCL9 and CXCL13 expression was strongly associated with cellular immunity. These results suggest that CXCL9‐expressing antigen‐presenting cells and CXCL13‐expressing follicular dendritic cells coordinately shape the immune‐activated microenvironment through TLS formation. The current findings will contribute to a better understanding of the mechanisms underlying the activated cancer immune microenvironment, thereby advancing the field of precision cancer medicine.

Prognostic Biomarker of Fertility‐Preserving Hormonal Therapy Based on Multigene Panel Testing for Endometrial Cancer

ABSTRACT In this study, we identified prognostic biomarkers that predict treatment outcome in patients receiving fertility‐preserving high‐dose medroxyprogesterone acetate (MPA) therapy through comprehensive multigene panel testing. A total of 38 patients (20 atypical endometrial hyperplasia and 18 stage IA G1 without myometrial invasion) who received first‐line MPA therapy were enrolled. Genomic DNA was extracted from formalin‐fixed paraffin‐embedded samples, and PleSSision‐Rapid multigene panel testing was performed. Of the 38 patients, 31 (82%) achieved complete response (CR), 2 (5%) had stable disease (SD), and 5 (13%) had progressive disease (PD) following initial treatment. The median duration to achieve tumor disappearance was 7 months (range: 4–14 months). Following initial treatment, 25 of 32 patients (78%) experienced recurrence, with a median recurrence‐free survival (RFS) of 21 months (range: 2–84 months). The most frequently observed actionable gene mutations were PTEN (68.4%), CTNNB1 (55.2%), and PIK3CA (33.3%). Patients harboring PTEN mutations in EMG1 required a significantly longer duration to achieve tumor disappearance ( p  = 0.011). In addition, the presence of PIK3CA mutations in AEH was significantly associated with shorter RFS ( p  = 0.048). Molecular classification identified 34 patients (89%) with no specific molecular profile (NSMP), 1 patient (3%) with POLE mutation, and 3 patients (8%) with deficient mismatch repair (d‐MMR). Most patients undergoing MPA therapy were classified as having NSMP. Genetic alterations, specifically mutations in PTEN and PIK3CA , were significantly associated with treatment outcomes, highlighting their potential as prognostic biomarkers.

Lymphadenectomy for primary ovarian cancer: a systematic review and meta-analysis

To assess the effectiveness of lymphadenectomy at primary debulking surgery (PDS) on the survival of patients with epithelial ovarian cancer (EOC). We searched PubMed, Ichushi, and the Cochrane Library. Randomized controlled trials (RCTs) and retrospective cohort studies comparing survival of women with EOC undergoing lymphadenectomy at PDS with that of women without lymphadenectomy were included. We performed a meta-analysis of overall survival (OS), progression-free survival (PFS), and adverse events. For advanced-stage EOC, 2 RCTs including 1,074 women and 7 cohort studies comprising 3,161 women were evaluated. Meta-analysis revealed that lymphadenectomy was associated with improved OS (hazard ratio [HR]=0.80; 95% confidence interval [CI]=0.70-0.90). However, meta-analysis of 2 RCTs revealed no significant difference in OS between the lymphadenectomy and no-lymphadenectomy groups (OS: HR=1.02; 95% CI=0.85-1.22). For early-stage EOC, 1 RCT comprising 268 women and 4 cohort studies comprising 14,228 women were evaluated. Meta-analysis showed that lymphadenectomy was associated with improved OS (HR=0.75; 95% CI=0.68-0.82). A RCT of early-stage EOC reported that lymphadenectomy was not associated with improved OS (HR=0.85; 95% CI=0.49-1.47). Surgery-related deaths were similar in both groups (risk ratio [RR]=1.00; 95% CI=0.99-1.01); however, blood transfusion was required less frequently in the no-lymphadenectomy group (RR=0.74; 95% CI=0.63-0.86). Meta-analysis of RCTs and observational studies suggest that lymphadenectomy was associated with improved OS in advanced- and early-stage EOC. However, results from RCTs demonstrate that lymphadenectomy was not associated with improved OS in advanced- and early-stage EOC.

Efficacy and safety of olaparib maintenance monotherapy for Japanese patients with platinum-sensitive relapsed ovarian, fallopian tube, and primary peritoneal cancer

Olaparib maintenance therapy for platinum-sensitive relapsed ovarian cancer has been approved in Japan since April 2018. Here, we report the experience administering this therapy in our hospital, with the aim of evaluating efficacy and safety in the Japanese population. The study included 52 patients with platinum-sensitive relapsed ovarian, fallopian tube, and primary peritoneal cancer. All patients started olaparib at a dose of 300 mg twice daily. Information about treatment efficacy and adverse effects was collected retrospectively from medical records. Median age was 58 years old (range: 33-80), and 82.7% of the patients were diagnosed with high-grade serous carcinoma. Sixteen patients (30.8%) possessed the BRCA1/2 pathogenic variant (15 germline and 1 tissue), 3 (5.8%) possessed variants of unknown significance (2 germline and 1 tissue), 16 (30.8%) possessed wild type, and 17 (32.7%) were not analyzed. Median progression-free survival was 15.3 months (95% CI 9.0-21.6). Patients with BRCA1/2 pathogenic variants showed significantly longer PFS than patients with wild-type BRCA1/2 (p = 0.007). Disease progression caused 34 cases to discontinue olaparib. Eighteen (34.6%) individuals exhibited ≥ grade 3 anemia, although they recovered in response to appropriate management. One patient discontinued olaparib because of prolonged renal dysfunction. Another patient presented with grade 3 fatigue, but recovered after 2 weeks of interruption and continued olaparib treatment. Olaparib maintenance therapy for platinum-sensitive recurrent ovarian cancer in the Japanese population is sufficiently safe and no less effective than reports from previous studies.

Sentinel node navigation surgery in cervical cancer: a systematic review and metaanalysis

Sentinel node navigation surgery (SNNS) is used in clinical practice for the treatment of cervical cancer. This study aimed to elucidate the appropriate sentinel lymph node (SLN) mapping method and assess the safety and benefits of SNNS. We searched the PubMed, Ichushi, and Cochrane Library databases for randomized controlled trials (RCT) and studies on SLN in cervical cancer from January 2012 to December 2020. Two authors independently assessed study quality and extracted data. We quantitatively analyzed the detection rate, sensitivity/specificity, and complications and reviewed information, including the survival data of SLN biopsy (SLNB) without pelvic lymphadenectomy (PLND). The detection rate of SLN mapping in the unilateral pelvis was median 95.7% and 100% and in the bilateral pelvis was median 80.4% and 90% for technetium-99 m (Tc) with/without blue dye (Tc w/wo BD) and indocyanine green (ICG) alone, respectively. The sensitivity and specificity of each tracer were high; the area under the curve of each tracer was 0.988 (Tc w/wo BD), 0.931 (BD w/wo Tc), 0.966 (ICG), and 0.977 (carbon nanoparticle). Morbidities including lymphedema, neurological symptoms and blood loss were associated with PLND. One RCT and five studies all showed SNNS without systematic PLND does not impair recurrence or survival in early-stage cervical cancer with a tumor size ≤ 2-4 cm. Both Tc w/wo BD and ICG are appropriate SLN tracers. SNNS can reduce the morbidities associated with PLND without affecting disease progression in early-stage cervical cancer.

Clinical availability and characteristics of multigene panel testing for recurrent/advanced gynecologic cancer

Japan's health insurance covers multigene panel testing. This study aimed to determine the potential availability and utility of gene panel testing clinically in gynecologic oncology. We analyzed the characteristics of patients with gynecologic cancer who underwent gene panel testing using FoundationOne Out of 102 patients analyzed, 32, 18, 43, 8, and 1 had cervical, endometrial, ovarian cancers, sarcoma, and vaginal cancer, respectively. Druggable gene alteration was found in 70 patients (68.6%; 21 with cervical cancer, 15 with endometrial cancer, 28 with ovarian cancer, 5 with sarcoma, and 1 with other). The most common druggable gene alteration was PIK3CA mutation (n = 21), followed by PTEN mutation (n = 12) and high tumor mutation burden (TMB-H) (n = 11). TMB-H was detected in 5 patients with cervical cancer, 5 with endometrial cancer, and 1 with endometrial stromal sarcoma. Eleven patients (10.8%) received molecularly targeted therapy according to their gene aberrations. Gene panel testing was mostly performed when the second-line treatment was ineffective. Of all 102 patients, 60 did not have recommended treatment, and 15 died or had worsened conditions before obtaining the test results. Through multigene panel testing, although many patients had druggable gene alterations, 10.8% of them received the recommended treatment. TMB-H was mainly observed in cervical/endometrial cancer, suggesting its potential as a therapeutic biomarker of immune checkpoint inhibitors. Furthermore, patients' prognosis and performance status should be considered before performing the test.

Prognostic impact of lymphadenectomy in patients with advanced ovarian clear cell carcinoma: an ancillary analysis of the JGOG3017-A4 study

Abstract Background Systematic pelvic and aortic lymphadenectomy in stage IIB–IVB patients with epithelial ovarian cancer, undergoing complete abdominal macroscopic resection with normal lymph nodes, was revealed to have no prognostic significance for survival in the LION trial. However, the proportion of patients with ovarian clear cell carcinoma (OCCC) in the LION trial was only 2.2%, so the significance of systematic retroperitoneal lymphadenectomy in patients with OCCC remains unclear. Methods We conducted an ancillary analysis of 619 patients enrolled in a randomized phase III trial (JGOG 3017) in patients with OCCC. Of these, 89 were stage IIB to IVB, underwent a complete macroscopic resection, and had no grossly enlarged lymph nodes intraoperatively. Patients were divided into two groups: group A with lymphadenectomy and group B without lymphadenectomy. The Kaplan–Meier method was used to calculate progression-free survival (PFS) and overall survival (OS) and the log-rank test and Cox proportional hazard model were used to compare the two groups. Results Among the 89 patients, 77 (86.5%) underwent a lymphadenectomy (group A), while 12 (13.5%) did not (group B). Three-year PFS were 62.3% in group A and 58.3% in group B ( p  = 0.7705). Three-year OS were 73.0% in group A and 65.6% in group B ( p  = 0.6346). No significant differences were observed between two groups. Conclusion This study did not demonstrate a definitive survival benefit from systematic lymphadenectomy in advanced OCCC patients with complete resection and clinically negative nodes. Given the small sample size, these results should be interpreted with caution and regarded as exploratory.

Gut microbiome associated with PARP inhibitor efficacy in patients with ovarian cancer

To investigate an association between the gut microbiome and efficacy of poly(ADP-ribose) polymerase inhibitors (PARPi) in ovarian cancer. This study conducted fecal microbiome analysis (16S rRNA gene sequencing) and circulating tumor DNA (ctDNA) profiling for ovarian cancer patients who underwent PARPi maintenance therapy. Fecal and blood samples were collected at the baseline and the progressive disease (PD) or last follow-up. The relative abundance of gut microbes and progression-free survival (PFS) were analyzed using linear discriminant analysis of effect size and the Cox proportional hazard model according to Baseline samples were available from 23 High fecal composition of