Sokbom Kang

Volume over location: prioritizing case volume over regional distribution in ovarian cancer treatment

The aim of this study was to examine the impact of hospital surgical volume and hospital region on overall survival (OS) in patients with ovarian cancer. This retrospective cohort study utilized nationwide claims data from Korea (2012-2020) to analyze ovarian cancer patients who underwent surgery. Hospitals were classified as high-volume (≥20) or low-volume (<20) based on the annual volume of upfront ovarian cancer surgeries. Propensity score matching (PSM) (1:1) addressed confounder imbalances between the groups. OS was assessed via Kaplan-Meier analysis, log-rank tests, and Cox regression, with subgroup analyses by cancer stage. A total of 11,510 patients were included in the cohort (high-volume: 8,241; low-volume: 3,269), with 3,236 matched pairs identified through PSM. Compared with low-volume hospitals, treatment at high-volume hospitals was associated with a 21% reduction in mortality risk (adjusted hazard ratio [aHR]=0.79; 95% confidence interval [CI]=0.70-0.89). This survival advantage persisted across localized/regional (aHR=0.77; 95% CI=0.63-0.95) and distant-stage disease (aHR=0.81; 95% CI=0.71-0.92). In contrast, hospital location (capital vs. noncapital) was not significantly associated with OS in the entire cohort (aHR=1.09; 95% CI=0.97-1.21) or in stage-specific analyses. These findings highlight that instead of simply distributing hospitals geographically, establishing high-volume surgical centers is crucial to improving survival outcomes for patients with ovarian cancer.

Treatment patterns and survival outcomes according to histologic subtype in malignant ovarian germ cell tumors: a nationwide real-world cohort study

Trends in the cost of ovarian cancer across phases of care and surgical years in Korea

This study aimed to estimate the medical costs among patients with ovarian cancer across distinct phases of care and surgical years. This population-based retrospective cohort study identified newly diagnosed ovarian cancer patients who underwent surgery based on nationwide claims data from Korea (2012-2019). Medical costs were categorized into 5 phases: neoadjuvant chemotherapy, surgery, frontline chemotherapy, monitoring, and recurrence. Total and cancer-related costs were analyzed by surgical year on a per patient and per patient per month (PPPM) basis. Per patient costs were estimated for each phase, with up to one year of follow-up per phase, for patients identified between 2013 and 2016. Generalized linear models (GLMs) examined associations between surgical year and cancer-related costs. Among 10,594 patients, median cancer-related costs per patient were highest in the recurrent phase ($20,548), followed by the frontline chemotherapy ($7,005), neoadjuvant chemotherapy ($5,870), surgery ($4,965), and monitoring phases ($1,906). The median surgery phase costs per patient increased from $4,254 in 2013 to $5,676 in 2016; recurrent phase costs increased from $17,289 to $26,750. GLM analysis revealed that per patient and PPPM costs significantly increased over time, particularly in the surgery and recurrent phases. Compared with the cost per patient in 2013, the cost per patient in 2016 was 27% higher for the surgery phase and 49% higher for the recurrent phase. Ovarian cancer-related costs have significantly increased over time, especially in the surgery and recurrent phases, thus highlighting the growing economic burden and the need for cost-effective care strategies.

The pathologic and clinical outcomes of risk-reducing salpingo-oophorectomy in asymptomatic carriers of homologous recombination repair gene mutation

To investigate the prevalence of pathological findings and clinical outcomes of risk-reducing salpingo-oophorectomy (RRSO) in asymptomatic carriers with germline homologous recombination repair (HRR) gene pathogenic/likely pathogenic variants (PV/LPV). 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. Of the 255 women who underwent RRSO, 129 (50.6%) had PV/LPV in 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.

How to manage synchronous endometrial and ovarian cancer patients?

Abstract Backgrounds We aimed to evaluate the prognosis in patients with synchronous endometrial and ovarian cancer (SEOC) by comparing the differences between double primary cancer (DPC) and metastatic cancer (MC). Methods The medical records of 47 patients diagnosed synchronously with endometrial and ovarian cancer between January 2006 and December 2018 were retrospectively reviewed. Twenty-eight and 19 patients were diagnosed with DPC and MC, respectively. Demographics, recurrence-free survival (RFS), and 5-year overall survival (OS) were compared. The clinical factors affecting survival were evaluated using univariate and multivariate analyses. Results The demographics were not different between both groups. Endometrioid histology and the International Federation of Gynecology and Obstetrics grade were higher in the MC group than in the DPC group (42.1% vs. 10.7%; P = 0.018, P = 0.002, respectively). The ratio of post-operative adjuvant therapy was not different in both groups. Recurrence occurred in five patients with DPC and seven with MC. The difference in RFS was not significantly different (P = 0.131) but the OS was different between both groups (P = 0.020). Histology and para-aortic lymph node metastasis were associated wtih RFS in univariate analysis, but no difference was found in multivariate analysis. Conclusions Although DPC patients had longer OS, multivariate analysis did not identify any influential factors. Focus should be placed on defining the appropriate adjuvant treatment for high-risk patients, which will improve prognosis, rather than on discriminating between DPC and MC.

Current treatment strategies for ovarian cancer in the East Asian Gynecologic Oncology Trial Group (EAGOT)

Ovarian cancer, notable for its severe prognosis among gynecologic cancers, has seen substantial progress in treatment approaches recently. Enhanced protocols in chemotherapy and the introduction of poly (ADP-ribose) polymerase (PARP) inhibitors for maintenance therapy have markedly improved outcomes for patients with specific genetic profiles, such as those positive for BRCA mutations or exhibiting homologous recombination deficiency (HRD). Additionally, the method of intraperitoneal chemotherapy administration has emerged as a valuable alternative to traditional transvenous routes, showing promise for wider clinical adoption. The field of surgery has also evolved, with increasing exploration into the benefits and feasibility of laparoscopic methods over more invasive traditional surgeries, aiming for complete tumor removal but with reduced patient impact. The hereditary nature of ovarian cancer underscores the importance of genetic testing, which has become integral in tailoring treatment strategies, particularly in determining suitability for PARP inhibitors. The formation of the East Asian Gynecologic Oncology Trial Group (EAGOT) aims to optimize treatment across Japan, Korea, China, and Taiwan. The ovarian cancer committee of EAGOT shared the current policies, focusing on 5 topics: 1) strategies for maintenance therapy after initial surgery and chemotherapy, 2) drug regimens for platinum-sensitive and platinum-resistant recurrence, 3) intraperitoneal chemotherapy, 4) laparoscopic surgery as an alternative to laparotomy, and 5) current status of genetic testing (BRCA, HRD, and panel tests) for ovarian cancer and its prospects. EAGOT's multi-national trials aim to harmonize these evolving treatment strategies, ensuring that the latest and most effective protocols are accessible across the region, thereby significantly impacting patient outcomes in East Asia.

Adherence of PARP inhibitor for frontline maintenance therapy in primary epithelial ovarian cancer: a cross-sectional survey

To identify the adherence rate to poly (ADP-ribose) polymerase (PARP) inhibitors and identify factors contributing to the deterioration of adherence at our institution. 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. 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-of-life 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. 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.

Survival Effects of Cytoreductive Surgery for Refractory Patients after Neoadjuvant Chemotherapy in Advanced Epithelial Ovarian Cancer

Salvage second-line chemotherapy is usually recommended for patients with advanced epithelial ovarian cancer (AEOC) who develop progressive disease (PD) after neoadjuvant chemotherapy (NAC). Herein, we investigated the role of cytoreductive surgery (CRS) for such patients. We retrospectively reviewed the medical records of 36 patients with AEOC who developed PD after receiving NAC at two tertiary academic centers with different treatment strategies between 2001 and 2016. Patients who developed PD after NAC were consistently treated with CRS at one hospital (group A; n=13) and second-line chemotherapy at another (group B; n=23). The clinical characteristics and treatment outcomes were compared between the groups. Overall survival (OS) was longer in group A than in group B (19.4 months vs. 7.9 months; CRS may result in a survival benefit even in patients with AEOC who develop PD after NAC.