A Deep Learning-Based Assessment Pipeline for Intraepithelial and Stromal Tumor-Infiltrating Lymphocytes in High-Grade Serous Ovarian Carcinoma.

Tumor-infiltrating lymphocytes (TILs) are associated with improved survival in patients with epithelial ovarian cancer. However, TIL evaluation has not been used in routine clinical practice because of reproducibility issues. The current study developed two convolutional neural network models to detect TILs and to determine their spatial location in whole slide images, and established a spatial assessment pipeline to objectively quantify intraepithelial and stromal TILs in patients with high-grade serous ovarian carcinoma. The predictions of the established models showed a significant positive correlation with the number of CD8+ T cells and immune gene expressions. Patients with a higher density of intraepithelial TILs had a significantly prolonged overall survival and progression-free survival in multiple cohorts. On the basis of the density of intraepithelial and stromal TILs, patients were classified into three immunophenotypes: immune inflamed, excluded, and desert. The immune-desert subgroup showed the worst prognosis. Gene expression analysis showed that the immune-desert subgroup had lower immune cytolytic activity and T-cell-inflamed gene-expression profile scores, whereas the immune-excluded subgroup had higher expression of interferon-γ and programmed death 1 receptor signaling pathway. The established evaluation method provided detailed and comprehensive quantification of intraepithelial and stromal TILs throughout hematoxylin and eosin-stained slides. It has potential for clinical application for personalized treatment of patients with ovarian cancer.

Artificial intelligence-based histopathological subtyping of high-grade serous ovarian cancer.

Four subtypes of ovarian high-grade serous carcinoma (HGSC) have previously been identified, each with different prognoses and drug sensitivities. However, the accuracy of the classification depended on the assessor's experience. This study aimed to develop a universal algorithm for HGSC-subtype classification using deep learning techniques. An artificial intelligence (AI)-based classification algorithm, which replicates the consensus diagnosis of pathologists, was formulated to analyze the morphological patterns and tumor-infiltrating lymphocyte counts for each tile extracted from whole slide images of ovarian HGSC available in The Cancer Genome Atlas (TCGA) dataset. The accuracy of the algorithm was determined using the validation set from the Japanese Gynecologic Oncology Group 3022A1 (JGOG3022A1) and Kindai and Kyoto University (Kindai/Kyoto) cohorts. The algorithm classified the four HGSC-subtypes with mean accuracies of 0.933, 0.910, and 0.862 for the TCGA, JGOG3022A1, and Kindai/Kyoto cohorts, respectively. To compare Mesenchymal Transition (MT) with non-MT groups, overall survival analysis was performed in the TCGA dataset. The AI-based prediction of HGSC-subtype classification in TCGA cases showed that the MT group had a worse prognosis than the non-MT group (p = 0.017). Furthermore, Cox proportional hazard regression analysis identified AI-based MT subtype classification prediction as a contributing factor along with residual disease after surgery, stage, and age. In conclusion, a robust AI-based HGSC-subtype classification algorithm was established using virtual slides of ovarian HGSC.

Interstitial lung disease caused by niraparib in ovarian cancer patient: a case report and literature review.

Drug-induced interstitial lung disease (DIILD) is one of the most common and important adverse drug reactions. Still, the details of the clinical presentation of DIILD caused by poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors are unknown. A 73-year-old Japanese woman was started on niraparib maintenance therapy after radical surgery and adjuvant chemotherapy for high-grade serous carcinoma originating from the fallopian tube. Forty-seven days after starting niraparib, she presented to the hospital with dyspnea and was diagnosed with DIILD caused by niraparib. The drug was discontinued, and the patient was treated with steroid pulse therapy, and her condition improved. In clinical trials of PARP inhibitors, DIILD was reported in 0.13% of patients with olaparib, but no DIILDs, including pneumonia or pneumonitis, were reported in any patient with niraparib. This is the first report of DIILD caused by niraparib worldwide. In the future, the frequency of DIILD caused by niraparib should be clarified in real-world data.

Trends in gynecologic cancer in Japan: incidence from 1980 to 2019 and mortality from 1981 to 2021.

BACKGROUND: In Japan, comprehensive cancer statistics data have been collected through national cancer registries, but these data are rarely summarized and reported in research articles. METHODS: Here, we compiled the national registry data on malignant tumors originating from gynecologic organs (ovary, corpus uteri, cervix uteri) in Japan. RESULTS: The number of new patients in 2019 was 13,380, 17,880, and 10,879, respectively, and the number of deaths in 2021 was 5081, 2741, and 2894, respectively. Compared with 40 years ago, the incidence of ovarian cancer has tripled, the incidence of uterine corpus cancer (mainly endometrial cancer) has increased eightfold, the mortality rate of uterine corpus cancer has tripled, and the incidence of cervical intraepithelial cancer has increased ninefold in data standardized by the world population. Compared with the United States, the incidence rate of ovarian cancer has overtaken and the mortality rate of uterine corpus cancer is the same, while both the incidence and mortality rates of cervical cancer are higher in Japan. CONCLUSION: The incidence of gynecologic cancer is increasing significantly in Japan.

Quality of care measurement for patients with ovarian cancer in Japan.

AIM: Quality of care is important to reduce disease progression, and improve both survival and quality of life. The Japan Society of Gynecologic Oncology has published treatment guidelines to promote standardized high-quality care for ovarian cancer in Japan. We developed quality indicators based on the guideline recommendations and used them on large datasets of health service use to examine the quality of ovarian cancer care. METHODS: A panel of experts developed the indicators using a modified Delphi method. Adherence to each indicator was evaluated using data from a hospital-based cancer registry of patients diagnosed in 2018. All patients receiving first-line treatment at participating facilities were included. The adherence rates were returned to participating hospitals, and reasons for nonadherence were collected. A total of 580 hospitals participated, and the study examined the care received by 6611 patients with ovarian cancer and 1879 with borderline tumors using 11 measurable quality indicators. RESULTS: The adherence rate ranged from 22.6% for "Estrogen replacement within 6 months of operation" to 93.5% for "Bleomycin, etoposide, and cisplatin for germ cell tumor more than Stage II." Of 580 hospitals, 184 submitted the reasons for nonadherence. CONCLUSIONS: The quality of ovarian cancer care should be continuously assessed to encourage the use of best practices. These indicators may be a useful tool for this purpose.

Critical evaluation on roles of macrophagic myofasciitis and aluminum adjuvants in HPV vaccine-induced adverse events.

Cervical cancer is caused by human papillomavirus (HPV) infection, which is preventable by HPV vaccines. In Japan, the HPV vaccination rate has remained extremely low due to the concerns for alleged neuropsychological symptoms or "diverse symptoms" following injections of two HPV vaccines, Cervarix and Gardasil, in HPV vaccine lawsuits. In the lawsuits, the attorneys' group has used several manuscripts proposing that aluminum (Al) adjuvant contained in HPV vaccines causes an immune-mediated disease, called macrophagic myofasciitis (MMF), as well as pathology in the central nervous system (CNS). We scientifically evaluated these manuscripts describing the "Al adjuvant-induced pathologies," particularly MMF. Although MMF patients have been reported to develop clinical symptoms/signs in various organs, including the CNS, muscle biopsy of the patients and animal experiments demonstrated that MMF pathology was localized only at the injected muscle. No muscle pathology which characterizes MMF was observed in any other muscles; thus, the systemic and neurological signs of MMF cases were irrelevant to localized MMF pathology. We evaluated that MMF-like pathology was induced as a local inflammatory response following vaccinations; MMF pathology was not the cause of systemic inflammation or "diverse symptoms." Lastly, MMF cases have been reported after vaccinations with Al-hydroxide-containing vaccines exclusively. As Al-hydroxide is a component of Cervarix, but not Gardasil, "diverse symptoms" following two HPV vaccinations in Japan cannot be explained by MMF. Our evaluation would help readers understand the validity of the manuscripts on the role of Al adjuvants or MMF for the alleged "diverse symptoms."

Homologous recombination inquiry through ovarian malignancy investigations: JGOG3025 Study.

The Cancer Genome Atlas (TCGA) network has clarified that ~50% of high-grade serous ovarian cancers show homologous recombination deficiency (HRD). However, the frequency of HRD in Japanese patients with ovarian cancer remains unclear. We aimed to identify the frequency of HR-associated gene mutations in Japanese patients with ovarian cancer. The JGOG3025 study is a multicenter collaborative prospective observational study involving 65 study sites throughout Japan. We recruited 996 patients who were clinically diagnosed with ovarian cancer before surgery from March 2017 to March 2019, and 701 patients were eligible according to the criteria. We used frozen tumor tissues to extract DNA and performed next-generation sequencing for 51 targeted genes (including 29 HR-associated genes) in 701 ovarian cancers (298 high-grade serous cases, 189 clear cell cases, 135 endometrioid cases, 12 mucinous cases, 3 low-grade serous cases, and 64 others). HRD was defined as positive when at least one HR-associated gene was mutated. The frequencies of HRD and tumor BRCA1/2 mutations were 45.2% (317/701) and 18.5% (130/701), respectively, in the full analysis set. Next, we performed multivariate Cox proportional hazards regression analysis for progression-free survival (PFS) and overall survival (OS). Advanced-stage ovarian cancer patients with HRD had adjusted hazard ratios of 0.72 (95% CI, 0.55-0.94) and 0.57 (95% CI, 0.38-0.86) for PFS and OS, respectively, compared with those without HRD (p = 0.016 and 0.007). Our study demonstrated that mutations in HR-associated genes were associated with prognosis. Further studies are needed to investigate the prognostic impact of each HR-associated gene in ovarian cancer.

Human papillomavirus vaccine impact on invasive cervical cancer in Japan: Preliminary results from cancer statistics and the MINT study.

The first prophylactic vaccine against human papillomavirus (HPV) 16 and HPV18 was licensed in Japan in 2009. HPV vaccine effectiveness against high-grade cervical lesions has been demonstrated among young Japanese women, but evidence of its effects on invasive cervical cancer (ICC) is lacking. Using data from two different cancer registries, we compared recent trends of new ICC cases by age group using Poisson regression analysis. We also analyzed time trends in HPV16/18 prevalence among 1414 Japanese women aged <40 years newly diagnosed with ICC in the past decade. Based on the population-based cancer registry, the incidence of ICC among young women aged 20-29 years showed a significant decline from 3.6 to 2.8 per 100 000 women-years during 2016-2019, but no similar decline was observed for older age groups (p < 0.01). Similarly, using data from the gynecological cancer registry of the Japan Society of Obstetrics and Gynecology, the annual number of ICCs among women aged 20-29 years also decreased from 256 cases to 135 cases during 2011-2020 (p < 0.0001). Furthermore, a declining trend in HPV16/18 prevalence in ICC was observed only among women aged 20-29 years during 2017-2022 (90.5%-64.7%, p = 0.05; Cochran-Armitage trend test). This is the first report to suggest population-level effects of HPV vaccination on ICC in Japan. Although the declining trend in HPV16/18 prevalence among young women with ICC supports a causal linkage between vaccination and results from cancer registries, further studies are warranted to confirm that our findings are attributable to vaccination.

Dynamic host immunity and PD-L1/PD-1 blockade efficacy: developments after "IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer".

In the article titled "IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer" in 2015, we showed that PD-L1 expression is induced by IFN-γ from lymphocytes in the tumour microenvironment. This article proposed that PD-L1 expression in cancer cells is not stable but varies among cases, or even within a case, which is influenced by the stromal infiltration of cytotoxic lymphocytes. Immune-checkpoint inhibitors, especially anti-PD-1/PD-L1 therapies, are now widely used to treat various types of cancer. Predictive biomarkers for the efficacy of immune-checkpoint inhibitors include PD-L1 expression, MSI/mismatch repair deficiency and high tumour mutation burden. However, clinical trials have proven that their use in ovarian cancer is still challenging. Reliable biomarkers and new treatment strategies may be sought by elucidating the complex immune microenvironment of ovarian cancer. Although the interaction between cytotoxic lymphocytes and PD-1/PD-L1 on tumour cells is at the centre of therapeutic targets, other immune checkpoints and various immunosuppressive cells also play important roles in ovarian cancer. Targeting these role players in combination with PD-1/PD-L1 blockade may be a promising therapeutic strategy.

Prognostic relevance of HRDness gene expression signature in ovarian high-grade serous carcinoma; JGOG3025-TR2 study.

BACKGROUND: This study aimed to evaluate the homologous recombination repair pathway deficiency (HRD) in ovarian high-grade serous carcinoma (HGSC). METHODS: In the ovarian cancer data from The Cancer Genome Atlas, we identified genes differentially expressed between tumours with and without HRD genomic scars and named these genes "HRDness signature". We performed SNP array, RNA sequencing, and methylation array analyses on 274 HGSC tumours for which targeted sequencing of 51 genes and clinical data were available to generate JGOG3025-TR2 dataset. The HRDness signature was tested on external datasets, including the JGOG3025-TR2 cohort, by computational scoring and machine-learning prediction. RESULTS: High scores and positive predictions of the HRDness signature were significantly associated with BRCA alterations, genomic scar scores, and better survival. On the other hand, among cases with high scores and/or positive predictions, those with BRCA1 methylation showed poorer survival. In the JGOG3025-TR2 cohort, HRD status was significantly associated with the use of olaparib after relapse and progression-free survival after its initiation. CONCLUSIONS: The HRDness gene expression signature is associated with a good prognosis, while BRCA1 methylation is associated with a poor prognosis. The newly generated JGOG3025-TR2 dataset will be useful in future HGSC studies.

Uterine angioleiomyoma with disseminated intravascular coagulation: a case report.

BACKGROUND: Uterine angioleiomyoma is benign tumor that composed of smooth muscle cells and thick-walled vessels. It is a very rare condition reported to present as lower abdominal mass, accompanied by dysmenorrhea and hypermenorrhea. However, its clinical presentation is not known. CASE PRESENTATION: We report the case of a 44-year-old Japanese woman who developed severe anemia with disseminated intravascular coagulation without obvious external bleeding. The patient had a huge abdominal mass of over 20 cm in size, which was thought to be a uterine tumor. She received daily blood transfusions and her condition improved rapidly after she underwent hysterectomy. Pathological examination of the tumor revealed spindle-shaped cells with little atypia and mitosis, and numerous large vessels with smooth muscle and thrombus in the vessels. CONCLUSIONS: Uterine angioleiomyoma was identified as the cause of the coagulation abnormality. CCND2 and AR gene amplification was detected in the tumor. Uterine tumors that present with coagulopathy despite a clinical course suggestive of benign disease should undergo differential diagnosis for uterine angioleiomyoma.

Synchronous ovarian and uterine mesonephric-like carcinoma that potentially arose from endometrioid adenofibroma: A case report.

Mesonephric-like carcinoma histologically resembles mesonephric adenocarcinoma (MA) of the cervix. MA arises from mesonephric duct remnants. However, the origin of mesonephric-like carcinoma is not extensively studied because of its rarity. Here, we present a case of synchronous ovarian and uterine mesonephric-like carcinoma that potentially arose from endometrioid adenofibroma. A 69-year-old woman presented with an abdominal mass with no genital bleeding. She underwent simple total abdominal hysterectomy and bilateral adnexal resection. Histological and immunohistochemical analyses were consistent with mesonephric-like carcinoma involving both ovaries and the uterus. Endometrioid adenofibroma was present in both ovaries, while adenomyosis was observed in the uterus. The glandular duct of the endometrioid adenofibroma in the right ovary had areas suggestive of precursor lesions of mesonephric-like carcinoma. All tumors exhibited the KRAS G12D mutation. These findings suggest that the origin of the mesonephric-like carcinoma was the Müllerian duct, and that the ovarian and uterine tumors were monoclonal.

Immunosuppressive tumor microenvironment in uterine serous carcinoma via CCL7 signal with myeloid-derived suppressor cells.

Serous carcinoma of the uterus (USC) is a pathological subtype of high-grade endometrial cancers, with no effective treatment for advanced cases. Since such refractory tumors frequently harbor antitumor immune tolerance, many immunotherapies have been investigated for various malignant tumors using immuno-competent animal models mimicking their local immunities. In this study, we established an orthotopic mouse model of high-grade endometrial cancer and evaluated the local tumor immunity to explore the efficacy of immunotherapies against USC. A multivariate analysis of 62 human USC cases revealed that the tumor-infiltrating cell status, few CD8+ cells and abundant myeloid-derived suppressor cells (MDSCs), was an independent prognostic factor (P < 0.005). A murine endometrial cancer cell (mECC) was obtained from C57BL/6 mice via endometrium-specific deletion of Pten and Tp53, and another high-grade cell (HPmECC) was established by further overexpressing Myc in mECCs. HPmECCs exhibited higher capacities of migration and anchorage-independent proliferation than mECCs (P < 0.01, P < 0.0001), and when both types of cells were inoculated into the uterus of C57BL/6 mice, the prognosis of mice bearing HPmECC-derived tumors was significantly poorer (P < 0.001). Histopathological analysis of HPmECC orthotopic tumors showed serous carcinoma-like features with prominent tumor infiltration of MDSCs (P < 0.05), and anti-Gr-1 antibody treatment significantly prolonged the prognosis of HPmECC-derived tumor-bearing mice (P < 0.05). High CCL7 expression was observed in human USC and HPmECC, and MDSCs migration was promoted in a CCL7 concentration-dependent manner. These results indicate that antitumor immunity is suppressed in USC due to increased number of tumor-infiltrating MDSCs via CCL signal.

Scientific evaluation of alleged findings in HPV vaccines: Molecular mimicry and mouse models of vaccine-induced disease.

Cervical cancer is caused by infections of the human papillomavirus (HPV), which can be prevented by vaccinations. In Japan, although about 3000 people die of cervical cancer annually, the HPV vaccination rate has remained extremely low in the eligible population since many Japanese have been concerned that "diverse symptoms," such as chronic pain, movement disorders, and cognitive impairment, may occur as adverse reactions after HPV vaccination. The concern has been raised by media coverage of the ongoing HPV vaccine lawsuits, in which the plaintiffs complained of their symptoms caused by HPV vaccination. The claims have been based on the alleged pathogenic findings in research articles on HPV vaccines, summarized in the document prepared by the plaintiffs' attorneys. We critically evaluated these articles, in which the authors proposed the following findings/hypothesis: (i) molecular mimicry between HPV L1 and human proteins leads to the production of cross-reactive antibodies; and (ii) HPV vaccine injection in mice causes damage in the brain, a mouse model for HPV vaccine associated neuro-immunopathic syndrome (HANS). We found that these hypotheses were based mainly on the findings from a few research groups and that all the articles had flaws in the method, result, or discussion sections. Our current evaluation should help better understand the validity of the findings, which have been often misunderstood as the truth by the general public. We propose to accumulate high-quality data on potential adverse events following HPV vaccination and to continue critically evaluating them.

Human papillomavirus vaccine effectiveness by age at first vaccination among Japanese women.

In Japan, the National Immunization Program against human papillomavirus (HPV) targets girls aged 12-16 years, and catch-up vaccination is recommended for young women up to age 26 years. Because HPV infection rates increase soon after sexual debut, we evaluated HPV vaccine effectiveness by age at first vaccination. Along with vaccination history, HPV genotyping results from 5795 women younger than 40 years diagnosed with cervical intraepithelial neoplasia grade 2-3 (CIN2-3), adenocarcinoma in situ (AIS), or invasive cervical cancer were analyzed. The attribution of vaccine-targeted types HPV16 or HPV18 to CIN2-3/AIS was 47.0% for unvaccinated women (n = 4297), but 0.0%, 13.0%, 35.7%, and 39.6% for women vaccinated at ages 12-15 years (n = 36), 16-18 years (n = 23), 19-22 years (n = 14), and older than 22 years (n = 91), respectively, indicating the greater effectiveness of HPV vaccination among those initiating vaccination at age 18 years or younger (P < .001). This finding was supported by age at first sexual intercourse; among women with CIN2-3/AIS, only 9.2% were sexually active by age 14 years, but the percentage quickly increased to 47.2% by age 16 and 77.1% by age 18. Additionally, the HPV16/18 prevalence in CIN2-3/AIS was 0.0%, 12.5%, and 40.0% for women vaccinated before (n = 16), within 3 years (n = 8), and more than 3 years after (n = 15) first intercourse, respectively (P = .004). In conclusion, our data appear to support routine HPV vaccination for girls aged 12-14 years and catch-up vaccination for adolescents aged 18 years and younger in Japan.

The roles and limitations of bevacizumab in the treatment of ovarian cancer.

Bevacizumab, an anti-VEGF antibody, targets mainly tumor blood vessels and exerts a cytostatic antitumor effect. In primary ovarian cancer, bevacizumab is used for 15 months, but its effect on progression-free survival disappears after 2 years and does not prolong overall survival. And in the treatment of primary ovarian cancer, there is no evidence that bevacizumab increases the intratumor concentration of chemotherapy and enhances response rates. On the other hand, bevacizumab is not affected by resistance mechanisms to chemotherapeutic agents or poly(ADP-ribose) polymerase (PARP) inhibitors. In the era of using PARP inhibitors for primary ovarian cancer, bevacizumab will become a molecularly targeted drug that will play a central role in chemo-refractory and recurrent ovarian cancer.

Individualization in the first-line treatment of advanced ovarian cancer based on the mechanism of action of molecularly targeted drugs.

With the development of poly(ADP-ribose) polymerase inhibitors, the treatment of advanced ovarian cancer is changing dramatically. The purpose of this narrative review is to provide a direction for the individualization of advanced ovarian cancer treatment based on the mechanism of action of molecularly targeted drugs currently used in Japan. The PAOLA-1 study showed very good progression-free survival in patients with homologous recombination deficiency tumors who underwent complete surgery with primary debulking surgery and who received olaparib plus bevacizumab. Niraparib has high intratumor penetration, and in a subgroup analysis of the PRIMA study, it was most effective in patients with residual tumors after interval debulking surgery. These data suggest the importance of achieving complete surgery and aiming for cure in the treatment of ovarian cancer and how the use of bevacizumab, olaparib, and niraparib should be individualized.

Oncologic outcomes in elderly patients who underwent hysterectomy for endometrial cancer: a multi-institutional survey in Kinki District, Japan.

BACKGROUND: The goal of this study is to assess the oncologic outcomes of elderly patients who underwent hysterectomy for endometrial cancer across three variables: hysterectomy approach, lymph node resection, and adjuvant therapy. METHODS: Hospital records of patients aged ≥ 70 years who underwent hysterectomy for endometrial cancer were obtained from 19 institutions. Patients were categorized into three risk groups: low, intermediate, and high. In each group, disease-free survival and overall survival were compared according to hysterectomy approach, lymph node resection, and adjuvant therapy using Kaplan-Meier method. Cox regression analysis with a 95% confidence interval was performed to estimate relative risk (RR) of death. RESULTS: A total of 1246 patients were included. In the low-risk group, the adjusted RR for death for minimally invasive surgery (MIS) versus laparotomy and lymph node resection versus no lymph node resection were 0.64 (0.24-1.72) and 0.52 (0.24-1.12), respectively. In the intermediate-risk group, the adjusted RR for death for MIS versus laparotomy, lymph node resection versus no lymph node resection, and adjuvant therapy versus no adjuvant therapy were 0.80 (0.36-1.77), 0.60 (0.37-0.98), and 0.89 (0.55-1.46), respectively. In the high-risk group, the adjusted RRs for death for lymph node resection versus no lymph node resection and adjuvant therapy versus no adjuvant therapy were 0.56 (0.37-0.86) and 0.60 (0.38-0.96), respectively. CONCLUSIONS: MIS is not inferior to laparotomy in uterine-confined diseases. Lymph node resection improved the outcome for all disease stages and histological types. In contrast, adjuvant therapy improved the outcomes only in high-risk patients.

PDK2 leads to cisplatin resistance through suppression of mitochondrial function in ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (CCC) exhibits an association with endometriosis, resistance to oxidative stress, and poor prognosis owing to its resistance to conventional platinum-based chemotherapy. A greater understanding of the molecular characteristics and pathogenesis of ovarian cancer subtypes may facilitate the development of targeted therapeutic strategies, although the mechanism of drug resistance in ovarian CCC has yet to be determined. In this study, we assessed exome sequencing data to identify new therapeutic targets of mitochondrial function in ovarian CCC because of the central role of mitochondria in redox homeostasis. Copy number analyses revealed that chromosome 17q21-24 (chr.17q21-24) amplification was associated with recurrence in ovarian CCC. Cell viability assays identified an association between cisplatin resistance and chr.17q21-24 amplification, and mitochondrion-related genes were enriched in patients with chr.17q21-24 amplification. Patients with high expression of pyruvate dehydrogenase kinase 2 (PDK2) had a worse prognosis than those with low PDK2 expression. Furthermore, inhibition of PDK2 synergistically enhanced cisplatin sensitivity by activating the electron transport chain and by increasing the production of mitochondrial reactive oxygen species. Mouse xenograft models showed that inhibition of PDK2 with cisplatin inhibited tumor growth. This evidence suggests that targeting mitochondrial metabolism and redox homeostasis is an attractive therapeutic strategy for improving drug sensitivity in ovarian CCC.

A Novel Malignant Peritoneal Mesothelioma with STRN Exon 2 and ALK Exon 20: A Case Report and Literature Review.

Recently, several malignant peritoneal mesotheliomas (MPMs), occurring in young women without asbestos exposure and with fusion genes such as anaplastic lymphoma kinase (ALK) and Ewing sarcoma breakpoint region 1, have been reported. In the present case, we encountered MPM with STRN-ALK fusion in a 17-year-old female adolescent. The case did not respond to chemotherapy and is currently in a clinical trial of alectinib. This is the fourth reported case of MPM with STRN-ALK fusion. Of the 45 cancer cases with STRN-ALK fusion in which the fusion partners were examined, all cases except for the current case showed fusion of exon 3 of STRN and exon 20 of ALK. This is the first case with fusion of exon 2 of STRN and exon 20 of ALK. Further advances in cancer genomic medicine may help clarify the clinical significance of this new fusion. KEY POINTS: Malignant peritoneal mesotheliomas (MPMs) can occur in young women without asbestos exposure and show fusion genes that activate anaplastic lymphoma kinase (ALK) by gene rearrangement. ALK rearrangement and the fusion partner can be detected by companion diagnostics and by next generation sequencing. Patients with MPMs with ALK rearrangement may benefit from target therapy.