Oncologic Outcomes of Patients with Early-Stage Cervical Cancer after Minimally Invasive Radical Hysterectomy and Sentinel Lymph Node Biopsy.

Background: The sentinel lymph node is the first node that cancer cells reach when migrating from the primary site. However, oncological outcomes after sentinel lymph node biopsy (SNB) have not been reported for cervical cancer. In this study, oncological outcomes were compared between patients receiving SNB and pelvic lymphadenectomy (PLD) for early-stage cervical cancer. Methods: One hundred and four patients with clinical stage 1A2, 1B1, and 2A1 cervical cancer were included in this study. All patients underwent laparoscopic or robot-assisted radical hysterectomy with SNB or PLD. Fifty-two patients with tumors ≤2 cm underwent SNB. Disease-free survival (DFS) and overall survival (OS) were compared between the groups. Results: The median (interquartile range) tumor size was 12 (7-20) mm in the SNB group and 20 (13-25) mm in the PLD group. Lymph node metastasis occurred in one patient in the SNB group and in nine patients in the PLD group. The median follow-up periods were 42 (24-60) and 82 (19-101) months in the SNB group and PLD group, respectively. The 3-year DFS rates were 100% in SNB and 91.5% in PLD. The 3-year OS was 100% in both groups. Conclusions: SNB was sufficient in cervical cancer patients with tumors ≤2 cm, suggesting that PLD might not be necessary for these patients.

Creation and Validation of Patient-Derived Cancer Model Using Peritoneal and Pleural Effusion in Patients with Advanced Ovarian Cancer: An Early Experience.

Background: The application of personalized cancer treatment based on genetic information and surgical samples has begun in the field of cancer medicine. However, a biopsy may be painful for patients with advanced diseases that do not qualify for surgical resection. Patient-derived xenografts (PDXs) are cancer models in which patient samples are transplanted into immunodeficient mice. PDXs are expected to be useful for personalized medicine. The aim of this study was to establish a PDX from body fluid (PDX-BF), such as peritoneal and pleural effusion samples, to provide personalized medicine without surgery. Methods: PDXs-BF were created from patients with ovarian cancer who had positive cytology findings based on peritoneal and pleural effusion samples. PDXs were also prepared from each primary tumor. The pathological findings based on immunohistochemistry were compared between the primary tumor, PDX, and PDX-BF. Further, genomic profiles and gene expression were evaluated using DNA and RNA sequencing to compare primary tumors, PDXs, and PDX-BF. Results: Among the 15 patients, PDX-BF was established for 8 patients (5 high-grade serous carcinoma, 1 carcinosarcoma, 1 low-grade serous carcinoma, and 1 clear cell carcinoma); the success rate was 53%. Histologically, PDXs-BF have features similar to those of primary tumors and PDXs. In particular, PDXs-BF had similar gene mutations and expression patterns to primary tumors and PDXs. Conclusions: PDX-BF reproduced primary tumors in terms of pathological features and genomic profiles, including gene mutation and expression. Thus, PDX-BF may be a potential alternative to surgical resection for patients with advanced disease.

Consistency between Primary Uterine Corpus Malignancies and Their Corresponding Patient-Derived Xenograft Models.

Patient-derived xenograft (PDX) models retain the characteristics of tumors and are useful tools for personalized therapy and translational research. In this study, we aimed to establish PDX models for uterine corpus malignancies (UC-PDX) and analyze their similarities. Tissue fragments obtained from 92 patients with uterine corpus malignancies were transplanted subcutaneously into immunodeficient mice. Histological and immunohistochemical analyses were performed to compare tumors of patients with PDX tumors. DNA and RNA sequencing were performed to validate the genetic profile. Furthermore, the RNA in extracellular vesicles (EVs) extracted from primary and PDX tumors was analyzed. Among the 92 cases, 52 UC-PDX models were established, with a success rate of 56.5%. The success rate depended on tumor histology and staging. The pathological and immunohistochemical features of primary and PDX tumors were similar. DNA sequencing revealed similarities in gene mutations between the primary and PDX tumors. RNA sequencing showed similarities in gene expressions between primary and PDX tumors. Furthermore, the RNA profiles of the EVs obtained from primary and PDX tumors were similar. As UC-PDX retained the pathological and immunohistochemical features and gene profiles of primary tumors, they may provide a platform for developing personalized medicine and translational research.

Hereditary breast and ovarian cancer triggered by occult fallopian tube cancer: a case report.

BACKGROUND: At the time of benign gynecological surgery, a prophylactic salpingo-oophorectomy or salpingectomy is increasingly being performed concurrently to reduce the risk of future ovarian and fallopian tube cancer. We herein describe a case of hereditary breast and ovarian cancer syndrome in which a hysterectomy and bilateral adnexectomy were performed with a preoperative diagnosis of benign tumor. A detailed pathological examination revealed occult fallopian tube cancer, and additional staging surgery provided an accurate pathology diagnosis. CASE PRESENTATION: A 72-year-old Japanese woman with a past history of breast cancer underwent a hysterectomy and bilateral oophoro-salpingectomy for the preoperative diagnosis of uterine myoma and a right para-ovarian cyst. In the detailed pathological examination, high-grade serous carcinoma of the right fallopian tube was detected incidentally, and a subsequent staging laparotomy confirmed single para-aortic lymph node metastasis. Furthermore, a mutation in germline BRCA2 was detected postoperatively, and the patient was finally diagnosed with hereditary breast and ovarian cancer syndrome. She was diagnosed with fallopian tube cancer International Federation of Gynecology and Obstetrics Stage IIIA1(i) and started on adjuvant therapy (six courses of paclitaxel and carboplatin followed by maintenance therapy with olaparib), and 18 months after surgery, she was free of disease. CONCLUSION: This is a case of fallopian tube cancer that was diagnosed incidentally and then accurately staged with additional advanced staging surgery. Even in the absence of grossly malignant findings, a detailed pathological search of the fallopian tubes and accurate staging surgery are important to make the necessary treatment decisions for the patient.

Lymphatic Complications Following Sentinel Node Biopsy or Pelvic Lymphadenectomy for Endometrial Cancer.

Sentinel node biopsy (SNB) is performed worldwide in patients with endometrial cancer (EC). The aim of this study was to evaluate and compare the occurrence rate of lymphatic complications between SNB and pelvic lymphadenectomy (LND) for EC. The medical records of women who underwent SNB or pelvic LND for EC between September 2012 and April 2022 were assessed. A total of 388 patients were enrolled in the current study. Among them, 201 patients underwent SNB and 187 patients underwent pelvic LND. The occurrence rates of lower-extremity lymphedema (LEL) and pelvic lymphocele (PL) were compared between the patients who underwent SNB and those who underwent pelvic LND. The SNB group had a significantly lower occurrence rate of lower-extremity LEL than the pelvic LND group (2.0% vs. 21.3%, p < 0.01). There were no patients who had PL in the SNB group; however, 4 (2.1%) patients in the pelvic LND group had PL. The occurrence rates of lower-extremity LEL and PL were significantly lower in patients who underwent SNB than those who underwent pelvic LND. SNB for EC has a lower risk of lymphatic complications compared to systemic LND.

Pretreatment Frequency of Circulating Th17 Cells and FeNO Levels Predicted the Real-World Response after 1 Year of Benralizumab Treatment in Patients with Severe Asthma.

Benralizumab treatment reduces exacerbations and improves symptom control and quality of life in patients with severe eosinophilic asthma. However, the determination of biomarkers that predict therapeutic effectiveness is required for precision medicine. Herein, we elucidated the dynamics of various parameters before and after treatment as well as patient characteristics predictive of clinical effectiveness after 1 year of benralizumab treatment in severe asthma in a real-world setting. Thirty-six patients with severe asthma were treated with benralizumab for 1 year. Lymphocyte subsets in peripheral blood samples were analyzed using flow cytometry. Treatment effectiveness was determined based on the ACT score, forced expiratory volume in 1 s (FEV1), and the number of exacerbations. Benralizumab provided symptomatic improvement in severe asthma. Benralizumab significantly decreased peripheral blood eosinophil and basophil counts and the frequencies of regulatory T cells (Tregs), and increased the frequencies of Th2 cells. To our knowledge, this is the first study to show benralizumab treatment increasing circulating Th2 cells and decreasing circulating Tregs. Finally, the ROC curve to discriminate patients who achieved clinical effectiveness of benralizumab treatment revealed that the frequency of circulating Th17 cells and FeNO levels might be used as parameters for predicting the real-world response of benralizumab treatment in patients with severe asthma.

Cancer-Specific miRNAs Extracted from Tissue-Exudative Extracellular Vesicles in Ovarian Clear Cell Carcinoma.

Ovarian clear cell carcinomas (OCCs) arise from endometriotic cysts that many women develop. Biomarkers for early OCC detection need to be identified. Extracellular vesicles have attracted attention as biomarker carriers. This study aims to identify cancer-specific miRNAs as novel OCC biomarkers using tissue-exudative extracellular vesicles (Te-EVs). Te-EVs were collected from four patients with OCC on one side and a normal ovary on the other side. Microarray analysis was performed to identify cancer-specific miRNAs in Te-EVs. Serum samples obtained before and after surgery from patients with OCC and atypical endometrial hyperplasia (AEH) (controls) were compared using real-time PCR to examine changes in the detected EV miRNA levels. Thirty-seven miRNAs were >2-fold upregulated on the OCC side compared with the normal ovarian side. We selected 17 miRNAs and created specific primers for 12 of these miRNAs. The levels of six EV miRNAs were significantly decreased in postoperative OCC serum compared to those in preoperative OCC serum. In contrast, no significant change was observed between the pre and postoperative values in the control group. We identified OCC tissue-specific miRNAs in the EVs secreted by OCC tissues. These EV miRNAs have potential for use as biomarkers for the early diagnosis and detection of OCC.

Malignant struma ovarii with thyroid-type papillary and poorly differentiated carcinoma: a case report.

BACKGROUND: Malignant struma ovarii is a very rare type of gynecologic cancer. Although its most common histological subtype is a pure type of papillary thyroid carcinoma containing two components, papillary carcinoma and poorly differentiated carcinoma, malignant struma ovarii is still extremely rare. As a result, the optimal treatment for this type of tumor remains uncertain due to its rarity. CASE PRESENTATION: A 62-year-old Japanese female presented with a pelvic tumor and clinical diagnosis of malignant tumor of the ovary. She underwent complete debulking surgery, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. The histology of the ovarian tumor revealed malignant struma ovarii with thyroid-type papillary projections and poorly differentiated carcinoma. Because of the complete resection and the absence of distant metastasis, the patient did not receive any adjuvant therapy. At 24 months after surgery, she was free of disease. CONCLUSION: This is a rare case report of malignant struma ovarii, without recurrence, in which the component was papillary thyroid carcinoma mixed with poorly differentiated carcinoma. Foregoing adjuvant therapy might be one option for malignant struma ovarii in cases with complete resection and no distant metastasis. In addition, we should consider that long-term follow-up is needed for malignant struma ovarii.

Robot-assisted modified radical hysterectomy with removal of lymphatic vessel using indocyanine green: A new method.

BACKGROUND: The sentinel lymph node (SLN) procedures using indocyanine green (ICG) have recently been performed worldwide. The aim of this study was to emphasise the safety of robot-assisted modified radical hysterectomy (RAMRH) with removal of the lymphatic vessels (RLV) using ICG in endometrial cancer according to a single surgeon's experience. METHODS: Robot-assisted modified radical hysterectomy with RLV using ICG was performed in patients with endometrial cancer. We compared 34 cases of RAMRH with RLV, with 54 patients without RLV. RESULTS: The median (interquartile range) time for the procedure did not differ between the RAMRH with and without RLV groups (88 [80-114] vs. 88 [79-104] min, p = 0.7). The success rate of RLV was 100% when SLNs were detected. CONCLUSION: Robot-assisted modified radical hysterectomy with RLV using ICG can completely dissect tissue from the uterus, including lymphatic vessels. This procedure using a robotic system with ICG, is simple and does not require additional time.

Validation of a Patient-Derived Xenograft Model for Cervical Cancer Based on Genomic and Phenotypic Characterization.

Patient-derived xenograft (PDX) models are useful tools for preclinical drug evaluation, biomarker identification, and personalized medicine strategies, and can be developed by the heterotopic or orthotopic grafting of surgically resected tumors into immunodeficient mice. We report the PDX models of cervical cancer and demonstrate the similarities among original and different generations of PDX tumors. Fresh tumor tissues collected from 22 patients with primary cervical cancer were engrafted subcutaneously into NOD.CB17-PrkdcSCID/J mice. Histological and immunohistochemical analyses were performed to compare primary and different generations of PDX tumors. DNA and RNA sequencing were performed to verify the similarity between the genetic profiles of primary and PDX tumors. Total RNA in extracellular vesicles (EVs) released from primary and PDX tumors was also quantified to evaluate gene expression. The total tumor engraftment rate was 50%. Histologically, no major differences were observed between the original and PDX tumors. Most of the gene mutations and expression patterns related to carcinogenesis and infiltration were similar between the primary tumor and xenograft. Most genes associated with carcinogenesis and infiltration showed similar expression levels in the primary tumor and xenograft EVs. Therefore, compared with primary tumors, PDX models could be potentially more useful for translational research.

Endometrial Cancer Patient-Derived Xenograft Models: A Systematic Review.

BACKGROUND: Because patient-derived xenograft (PDX) models resemble the original tumors, they can be used as platforms to find target agents for precision medicine and to study characteristics of tumor biology such as clonal evolution and microenvironment interactions. The aim of this review was to identify articles on endometrial cancer PDXs (EC-PDXs) and verify the methodology and outcomes. METHODS: We used PubMed to research and identify articles on EC-PDX. The data were analyzed descriptively. RESULTS: Post literature review, eight studies were selected for the systematic review. Eighty-five EC-PDXs were established from 173 patients with EC, with a total success rate of 49.1%. A 1-10 mm3 fragment was usually implanted. Fresh-fragment implantation had higher success rates than using overnight-stored or frozen fragments. Primary tumors were successfully established with subcutaneous implantation, but metastasis rarely occurred; orthotopic implantation via minced tumor cell injection was better for metastatic models. The success rate did not correspond to immunodeficiency grades, and PDXs using nude mice reduced costs. The tumor growth period ranged from 2 weeks to 13 months. Similar characteristics were observed between primary tumors and PDXs, including pathological findings, gene mutations, and gene expression. CONCLUSION: EC-PDXs are promising tools for translational research because they closely resemble the features of tumors in patients and retain molecular and histological features of the disease.

Effect of Japanese Cedar Pollen Sublingual Immunotherapy on Asthma Patients with Seasonal Allergic Rhinitis Caused by Japanese Cedar Pollen.

Allergen immunotherapy is a promising treatment for allergic diseases that induce immune tolerance through the administration of specific allergens. In this study, we investigate the efficacy of sublingual immunotherapy (SLIT) in asthmatic patients with SAR-JCP and the dynamics of the parameters before and after treatment in a real-world setting. This was a prospective single-center observational study. Patients with asthma and SAR-JCP (n = 24) were recruited for this study and assessed using symptom questionnaires before SLIT and a year after the SLIT. In addition, a respiratory function test, forced oscillation technique, and blood sampling test were performed during the off-season before and after SLIT. The one-year SLIT for asthma patients with SAR-JCP significantly improved not only allergic rhinitis symptoms, but also asthma symptoms during the JCP dispersal season, and significantly improved airway resistance during the off-season. The change in the asthma control test and the visual analog scale score during the season before and after SLIT was negatively and positively correlated with the change in peripheral blood γδ T cells off-season before and after SLIT, respectively. It was suggested that improvement in asthma symptoms during the JCP dispersal season after SLIT was associated with reduced peripheral blood γδ T cells.

Comparison of Prognosis between Minimally Invasive and Abdominal Radical Hysterectomy for Patients with Early-Stage Cervical Cancer.

Minimally invasive surgery (MIS) is performed to treat cervical cancer patients; however, a recent study showed that MIS was associated with higher recurrence and death rate compared with abdominal radical hysterectomy (ARH). In the current study, the prognosis of patients with early-stage cervical cancer who underwent MIS with vaginal closure or ARH was evaluated. One hundred and eighty-two patients underwent radical hysterectomy for cervical cancer with stage of IA2, IB1, and IIA1. MIS was performed by laparoscopy or a robot using the vaginal closure method. Disease-free survival (DFS) and overall survival (OS) were evaluated between the groups. Among the patients, 67 underwent MIS and 115 underwent ARH. The recurrence rate was 4.5% in MIS patients and 3.5% in ARH patients with a median follow-up (interquartile range) of 36 (18-60) and 78 (48-102) months, respectively. DFS and OS were not different between the groups (3y-DFS, 95.3% vs. 96.1%, p = 0.6; 3y-OS, 100% vs. 100%, p = 0.06). In early-stage cervical cancer patients, MIS with vaginal closure did not increase the risk for recurrence or death. Surgical techniques and procedures to avoid spillage of tumor cells could be important for a better prognosis.

Patient-Derived Xenograft Models in Cervical Cancer: A Systematic Review.

BACKGROUND: Patient-derived xenograft (PDX) models have been a focus of attention because they closely resemble the tumor features of patients and retain the molecular and histological features of diseases. They are promising tools for translational research. In the current systematic review, we identify publications on PDX models of cervical cancer (CC-PDX) with descriptions of main methodological characteristics and outcomes to identify the most suitable method for CC-PDX. METHODS: We searched on PubMed to identify articles reporting CC-PDX. Briefly, the main inclusion criterion for papers was description of PDX created with fragments obtained from human cervical cancer specimens, and the exclusion criterion was the creation of xenograft with established cell lines. RESULTS: After the search process, 10 studies were found and included in the systematic review. Among 98 donor patients, 61 CC-PDX were established, and the overall success rate was 62.2%. The success rate in each article ranged from 0% to 75% and was higher when using severe immunodeficient mice such as severe combined immunodeficient (SCID), nonobese diabetic (NOD) SCID, and NOD SCID gamma (NSG) mice than nude mice. Subrenal capsule implantation led to a higher engraftment rate than orthotopic and subcutaneous implantation. Fragments with a size of 1-3 mm3 were suitable for CC-PDX. No relationship was found between the engraftment rate and characteristics of the tumor and donor patient, including histology, staging, and metastasis. The latency period varied from 10 days to 12 months. Most studies showed a strong similarity in pathological and immunohistochemical features between the original tumor and the PDX model. CONCLUSION: Severe immunodeficient mice and subrenal capsule implantation led to a higher engraftment rate; however, orthotopic and subcutaneous implantation were alternatives. When using nude mice, subrenal implantation may be better. Fragments with a size of 1-3 mm3 were suitable for CC-PDX. Few reports have been published about CC-PDX; the results were not confirmed because of the small sample size.

Pelvic Abscess after Cesarean Section Treated with Laparoscopic Drainage.

Cesarean section (CS), the rate of which is increasing worldwide, may be associated with complications. Although pelvic abscess after CS is rare, it is difficult to treat. We herein report two cases of pelvic abscess treated laparoscopically after CS. The abscesses of the patients were located in the pouch of Douglas and the uterine scar after CS, respectively. Several days after CS, the patients presented with lower abdominal pain and fever. Laparoscopic drainage was performed because imaging revealed a pelvic abscess that was not amenable to drainage through interventional radiology. The patients recovered from infection and were discharged four days after drainage.

A case of hand urticaria, lip angioedema, and oropharyngeal pruritus induced by Japanese radish through IgE-mediated immediate allergic reaction.

BACKGROUND: Although Japanese radish (Raphanus sativus L.) is a common Japanese ingredient, there are few reports of IgE-mediated immediate food allergy caused by Japanese radish. CASE PRESENTATION: A 48-year-old woman developed urticarial lesions on her hands after grating Japanese radish and also developed lip edema and oral itching when she ate a salad composed of raw Japanese radishes. Skin prick testing was positive to extract of grated Japanese radish. Moreover, immunoblotting analysis showed IgE reactivity in the patient's serum to a single band at the 18 kDa in grated Japanese radish, suggesting that the heat-labile 18 kDa protein of raw Japanese radish may be a radish-specific antigen. CONCLUSIONS: To the best of our knowledge, this is the first case report of a patient with hand urticaria, lip angioedema, and oropharyngeal pruritus to raw Japanese radish through IgE-mediated immediate allergic reaction.

Transformation from adenocarcinoma to squamous cell lung carcinoma with MET amplification after lorlatinib resistance: A case report.

To date, several studies have described the mechanism of resistance to first- or second-generation anaplastic lymphoma kinase (ALK) inhibitors. Secondary ALK mutations, ALK gene amplification, and other bypass signal activations (i.e., KRAS mutation, EGFR mutation, amplification of KIT, and increased autophosphorylation of EGFR) are known as resistance mechanisms. However, little has been previously reported on acquired resistance mechanisms to lorlatinib. Here, we report a case of a patient with ALK-positive lung adenocarcinoma that acquired resistance to lorlatinib during treatment for brain metastasis and showed histological transformation to squamous cell carcinoma with MET amplification. We also review the previous literature on the resistance mechanism to ALK inhibitors.

Prognostic significance of peritoneal cytology in low-risk endometrial cancer: comparison of laparoscopic surgery and laparotomy.

BACKGROUND: There is uncertainty surrounding the prognostic value of peritoneal cytology in low-risk endometrial cancer, especially in laparoscopic surgery. The objective of this retrospective study is to determine the prognostic significance of positive peritoneal cytology among patients with low-risk endometrial cancer and to compare it between laparoscopic surgery and conventional laparotomy. METHODS: From August 2008 to December 2019, all cases of pathologically confirmed stage IA grade 1 or 2 endometrial cancer were reviewed at Osaka Medical College. Statistical analyses used the Chi-square test and the Kaplan-Meier log rank. RESULTS: A total of 478 patients were identified: 438 with negative peritoneal cytology (232 who underwent laparotomy and 206 who undertook laparoscopic surgery) and 40 with positive peritoneal cytology (20 who underwent laparotomy and 20 who received laparoscopic surgery). Survival was significantly worse among patients with positive peritoneal cytology compared to patients with negative peritoneal cytology. However, there was no significant difference among patients with negative or positive peritoneal cytology between laparoscopic surgery and laparotomy. CONCLUSION: This retrospective study suggests that, while peritoneal cytology is an independent risk factor in patients with low-risk endometrial cancer, laparoscopic surgery does not influence the survival outcome when compared to laparotomy.

Oncologic outcomes for patients with endometrial cancer who received minimally invasive surgery: a retrospective observational study.

BACKGROUND: Laparoscopic hysterectomy has been performed for patients with endometrial cancer as minimally invasive surgery; however, the long-term outcomes of high-risk disease compared to open surgery remain unclear. METHODS: Eight hundred and eighty-three patients with endometrial cancer who underwent laparoscopic or abdominal hysterectomy were categorized into three groups. Low-risk disease was defined as stage IA disease with endometrioid carcinoma of grade 1 or 2. Uterine-confined disease was defined as stage IA disease with high-grade tumors or stage IB and II disease. Advanced disease was defined as stage III or IV disease. The progression-free survival (PFS) and overall survival (OS) rates were compared between laparoscopic and laparotomic hysterectomy. RESULTS: Among 478 patients with low-risk disease, including 226 with laparoscopy and 252 with laparotomy, the prognosis was not significantly different between the groups (3-year PFS rate, 97.4% vs. 97.1%, p = 0.8; 3-year OS rate, 98.6% vs. 98.3%, p = 0.9). Among the 229 patients with uterine-confined disease, including 51 with laparoscopy and 178 with laparotomy, the prognosis was not significantly different between the groups (3-year PFS rate, 90.5% vs. 85.5%, p = 0.7; 3-year OS rate, 91.3% vs. 92.5%, p = 0.8). Among the 176 patients with advanced disease, including 24 with laparoscopy and 152 with laparotomy, laparoscopic hysterectomy had a higher PFS rate and OS rate than laparotomic hysterectomy (3-year PFS rate, 74.5% vs. 51.5%, p = 0.01; 3-year OS rate, 92.3% vs. 75.1%, p = 0.03). CONCLUSIONS: Laparoscopic procedures are not associated with a poorer outcome than laparotomy in patients with advanced endometrial cancer or uterine-confined endometrial cancer.

Serum exosomal microRNA-34a as a potential biomarker in epithelial ovarian cancer.

BACKGROUND: Ovarian cancer (OC) is a leading cause of cancer-related death in women, and thus an accurate diagnosis of the predisposition and its early detection is necessary. The aims of this study were to determine whether serum exosomal microRNA-34a (miR-34a) in ovarian cancer could be used as a potential biomarker. METHODS: Exosomes from OC patients' serum were collected, and exosomal miRNAs were extracted. The relative expression of miR-34a was calculated from 58 OC samples by quantitative real-time polymerase chain reaction. RESULTS: Serum exosomal miR-34a levels were significantly increased in early-stage OC patients compared with advanced-stage patients. Its levels were significantly lower in patients with lymph node metastasis than in those with no lymph node metastasis. Furthermore, its levels in the recurrence group were significantly lower than those in the recurrence-free group. CONCLUSIONS: Serum exosomal miR-34a could be a potential biomarker for improving the diagnostic efficiency of OC.