We updated the Korean Society of Gynecologic Oncology (KSGO) practice guideline for the management of ovarian cancer as version 5.1. The ovarian cancer guideline team of the KSGO published announced the fifth version (version 5.0) of its clinical practice guidelines for the management of ovarian cancer in December 2023. In version 5.0, the selection of the key questions and the systematic reviews were based on the data available up to December 2022.Therefore, we updated the guidelines version 5.0 with newly accumulated clinical data and added 5 new key questions reflecting the latest insights in the field of ovarian cancer between 2023 and 2024. For each question, recommendation was provided together with corresponding level of evidence and grade of recommendation, all established through expert consensus.

We updated the Korean Society of Gynecologic Oncology (KSGO) practice guideline for the management of ovarian cancer as version 5.1. The ovarian cancer guideline team of the KSGO published announced the fifth version (version 5.0) of its clinical practice guidelines for the management of ovarian cancer in December 2023. In version 5.0, the selection of the key questions and the systematic reviews were based on the data available up to December 2022.Therefore, we updated the guidelines version 5.0 with newly accumulated clinical data and added 5 new key questions reflecting the latest insights in the field of ovarian cancer between 2023 and 2024. For each question, recommendation was provided together with corresponding level of evidence and grade of recommendation, all established through expert consensus.

We updated the Korean Society of Gynecologic Oncology (KSGO) practice guideline for the management of ovarian cancer as version 5.1. The ovarian cancer guideline team of the KSGO published announced the fifth version (version 5.0) of its clinical practice guidelines for the management of ovarian cancer in December 2023. In version 5.0, the selection of the key questions and the systematic reviews were based on the data available up to December 2022.Therefore, we updated the guidelines version 5.0 with newly accumulated clinical data and added 5 new key questions reflecting the latest insights in the field of ovarian cancer between 2023 and 2024. For each question, recommendation was provided together with corresponding level of evidence and grade of recommendation, all established through expert consensus.

Objective: To investigate the prevalence of pathological findings and clinical outcomes of riskreducing salpingo-oophorectomy (RRSO) in asymptomatic carriers with germline homologous recombination repair (HRR) gene pathogenic/likely pathogenic variants (PV/LPV). Methods: This retrospective study enrolled asymptomatic carriers with germline HR gene PV/ LPV who underwent RRSO between 2006 and 2022 at the National Cancer Center in Korea.Clinical characteristics, including history of breast cancer, family history of ovarian/breast cancer, parity, and oral contraceptive use, were analyzed. Results: Of the 255 women who underwent RRSO, 129 (50.6%) had PV/LPV in BRCA1, 121 (47.5%) in BRCA2, and 2 (0.7%) had both BRCA1 and BRCA2 PV/LPV. In addition, 1 carried PV/ LPV in RAD51D, and 2 in BRIP1. Among the BRCA1/2 PV/LPV carriers, occult neoplasms were identified in 3.5% of patients: serous tubal intraepithelial carcinoma (1.1%, n=3), fallopian tubal cancers (0.8%, n=2), ovarian cancer (1.2%, n=3), and breast cancer (0.4%, n=1). Of the 9 patients with occult neoplasms, 5 (2.0%) were identified from the 178 breast cancer patients, and 4 (1.6%) were detected in 65 healthy mutation carriers. During the median follow-up period of 36.7 months (interquartile range, 25.9–71.4), 1 (0.4%) BRCA1 PV carrier with no precursor lesions at RRSO developed primary peritoneal carcinomatosis after 30.1 months. Conclusion Women with HRR gene mutations PV/LPV who undergo RRSO are at a risk of detecting occult neoplasms, with a of 3.5%. Even in the absence of precursor lesions during RRSO, there was a cumulative risk of peritoneal carcinomatosis development, emphasizing the need for continued surveillance.

Objective: Because of the possible therapeutic benefit of removing occult tumor cells, a source of recurrence and chemoresistance, total parietal peritonectomy (TPP) is an alternative treatment for advanced epithelial ovarian/fallopian tube/primary peritoneal cancer. Interventional studies comparing TPP with selective parietal peritonectomy (SPP) are in progress. Since surgeons skilled in TPP are essential for such trials to be conducted, this nationwide survey aimed to examine current peritonectomy practice among gynecologic oncologists in Korea. Methods: A 17-item questionnaire, developed by a surgery committee and reviewed by the scientific review board of the Korean Gynecology Oncology Group (KGOG), was distributed to 144 KGOG members. The questionnaire was divided into 3 categories: respondent demographics, peritonectomy practice during primary debulking surgery (PDS), and peritonectomy practice during interval debulking surgery (IDS). Results: We received 88 (61.1%) valid responses. Of the valid respondents, 98.9% and 93.8% performed SPP during PDS and IDS, respectively. Only 4.9% of the respondents performed TPP during IDS. Most respondents performed peritonectomy in cases where optimal postoperative outcomes were expected. Approximately 50.6% of the respondents had performed peritonectomy independently, while the others did so in cooperation with non-gynecologic surgeons. The primary reasons for not performing TPP were concerns about morbidity and uncertainty about the clinical benefits of the procedure. Conclusion SPP is the predominant technique used in both PDS and IDS in Korea. A small percentage (4.9%) of gynecologic oncologists have performed TPP during IDS. Accordingly, a study regarding the feasibility of TPP should be conducted before proceeding with a prospective clinical trial.

Background: Mismatch repair deficient (MMRd) tumors are known to be highly immunogenic and of great interest for immune checkpoint inhibitor. However, there is no data about the complete response (CR) rate of programmed cell death protein 1 (PD-1) blockade and surgery in subjects with MMRd surgically resectable endometrial cancer. In this regard, we suggest a window of opportunity study of induction PD-1 blockade (nivolumab) in patients with surgically resectable MMRd endometrial cancer. Methods This is a multicenter, single-arm phase II trial. A total of 30 surgically resectable MMRd endometrial cancer patients will be enrolled. Inclusion criteria include clinical stage I–IIIC2, tumor specimen that demonstrates MMRd by immunohistochemistry or microsatellite instability. Exclusion criteria include multiple primary cancers, residual adverse effects of prior therapy or effects of surgery. Patients are treated with nivolumab 480 mg intravenously every 4 weeks up to 6 months followed by standard surgery and/or adjuvant treatment. The primary endpoint of the study is clinical CR rate or pathological CR rate after treatment of nivolumab. Secondary endpoints include objective response rate, progressionfree survival, overall survival, and adverse events. Correlative studies include genomic characterization of tumors, assessment of immune infiltration of tumor microenvironment, and serial circulating cell-free DNA and immune biomarkers.

Objective: Serous tubal intraepithelial carcinoma (STIC), a potential precursor of high-grade serous carcinoma, is associated with subsequent carcinomas development. This study aimed to identify cases of STIC and serous tubal intraepithelial lesions (STIL) and examine clinical outcomes and patterns of care in BRCA1/2 mutations carriers undergoing risk-reducing salpingo-oophorectomy (RRSO), as well as patients with incidental STIC/STIL after benign gynecologic surgery. Methods: This retrospective study was conducted at six institutions to examine patients with isolated STIC/STIL. Demographic, adjuvant treatment, and follow-up data were collected from the date of implementation of Sectioning and Extensively Examining the Fimbriated end protocol, which varied from 2006 to 2015, until December 2022. Results: We analyzed the data of 1,119 women who underwent RRSO and were carriers of BRCA1/2 mutations. The detection rate of isolated STIC/STIL was 1.70%. No patient with STIC/STIL received adjuvant chemotherapy or staging operations. The institutions used different surveillance intervals and methods, with the most common being a 3–6 month interval (11 of 19 patients) and gynecological sonography (17 of 19 patients). All patients remained with no evidence of disease (NED) throughout the follow-up period (2–121 months). Additionally, we analyzed data from five women with incidental STIC/ STIL diagnosed after benign gynecological surgery; one woman underwent staging surgery.During the follow-up period (3–46 months), all patients remained in NED. Conclusion While patient monitoring after STIC/STIL detection may be considered due to the minimal risk of carcinoma, excessive concern may not be necessary. Furthermore, adjuvant chemotherapy should be considered only with caution.

Since the latest practice guidelines for ovarian cancer were developed by the Korean Society of Gynecologic Oncology (KSGO) in 2021, many studies have examined the efficacy and safety of various treatments for epithelial ovarian cancer (EOC). Therefore, the need to develop recommendations for EOC treatments has been raised. This study searched the literature using 4 key items and the Population, Intervention, Comparison, and Outcome: the efficacy and safety of poly-ADP ribose polymerase inhibitors in newly diagnosed advanced EOC; the efficacy and safety of intraperitoneal plus intravenous chemotherapy in optimally debulked advanced EOC; the efficacy and safety of secondary cytoreductive surgery in platinumsensitive recurrent ovarian cancer; and the efficacy and safety of the addition of bevacizumab to platinum-based chemotherapy in first platinum-sensitive recurrent EOC patients who received prior bevacizumab. The evidence for these recommendations, according to each key question, was evaluated using a systematic review and meta-analysis. The committee of ovarian cancer of the KSGO developed updated guidelines for treatments of EOC.

Objective: To investigate the incidence and survival outcomes of ovarian carcinosarcoma in Korea between 1999 and 2018. Methods: Patients diagnosed with ovarian carcinosarcoma between 1999 and 2018 were identified from the Korea Central Cancer Registry (KCCR) and their information was collected. Age-standardized incidence rates (ASRs), annual percent changes (APC), and relative survival rates of ovarian carcinosarcoma were calculated and compared to those of epithelial ovarian cancer. Results: According to the KCCR, 458 cases of ovarian carcinosarcoma were detected, and accounted for 1.5% (458/30,679) of all epithelial ovarian cancers in Korea between 1999 and 2018. The ASR of ovarian carcinosarcoma between 1999 and 2018 was 0.064 per 100,000 women. The incidence rate of ovarian carcinosarcoma increased during the study period, with an ASR of 0.029 per 100,000 in 1999 and 0.073 per 100,000 in 2018. The APC of ovarian carcinosarcoma during 1999–2018 was 5.86 (p<0.001). The median overall survival (OS) of patients with ovarian carcinosarcoma was 39 months, and the 5-year OS rate was 42.5%.Among ovarian carcinosarcomas, patients with localized stages showed better clinical outcomes than those with regional or distant stages (5-year OS, 60.8%, 57.9%, and 32.8%, respectively; p<0.001). In addition, younger (<50 years) patients showed better OS than older (≥50 years) patients (5-year OS, 52.6% vs. 40.2%; p<0.001). Conclusion Our nationwide registry-based study demonstrated that the incidence of ovarian carcinosarcoma increased from 1999 to 2018 in Korea. Patients with advanced-stage disease and older age (≥50 years) had poorer survival outcomes.

Objective: To identify the adherence rate to poly (ADP-ribose) polymerase (PARP) inhibitors and identify factors contributing to the deterioration of adherence at our institution. Methods: The adherence rate to PARP inhibitors was calculated using self-reported Adherence to Refills and Medications Scale questionnaires from a cross-sectional survey. Multivariable logistic regression analysis was performed to identify the factors that affected adherence. Results: Of the 131 respondents, 32 (24.4%) showed non-adherence to PARP inhibitors.In the multivariable logistic regression analysis, unemployed or retired status (odds ratio [OR]=4.878; 95% confidence interval [CI]=1.528–15.572; p=0.008), patients receiving niraparib (OR=3.387; 95% CI=1.283–8.940; p=0.014), and a lower score on the quality-oflife assessment (EORTC-QLQ-OV28), which reflects a better quality of life (QOC) with a lower symptom burden (OR=1.056; 95% CI=1.027–1.086; p<0.001) were associated with high adherence to PARP inhibitors. Conclusion Approximately one-fourth of patients with ovarian cancer are non-adherent to PARP inhibitors as maintenance treatment for newly diagnosed advanced ovarian cancer. The occupational status, type of PARP inhibitor, and QOC may affect adherence to PARP inhibitors.