Objective: In the differential diagnosis between uterine fibroids and uterine sarcomas, realworld magnetic resonance imaging (MRI) diagnostic information is scarce; furthermore, high diagnostic sensitivity is important in clinical practice. We previously developed a diagnostic algorithm to detect uterine sarcoma with high sensitivity using simple MRI images and serum lactate dehydrogenase (LDH) levels. In this multicenter study, we investigated the preoperative diagnosis of sarcoma in the real world and further validated the usefulness of our diagnostic algorithm. Methods: Of 154 uterine sarcomas and 154 uterine fibroids treated at 15 centers between January 2006 and December 2020, 139 sarcomas (16 smooth muscle tumors of uncertain malignant potential) and 141 fibroids with diffusion-weighted imaging information were included in the analysis. The diagnostic algorithm was validated by 3 radiologists who were blinded to the clinical information and pathologic diagnoses and who read the MRIs. Results: The sensitivity/specificity of preoperative diagnosis was 77.7%/92.9% for the preoperative report; 92.1%/72.3% for algorithm A; and 82.0%/85.8% for algorithm B (McNemar’s test p<0.05). Comparison of overall survival rates among 3 groups (Group 1: negative A, Group 2: positive A and negative B; Group 3: positive B) using algorithms A and B showed p=0.012. On multivariate analysis, stage, and serum LDH level were independent prognostic factors. Conclusion MRI is useful for preoperative diagnosis of uterine sarcoma, and the sarcoma diagnostic algorithm presented in this study is an option for diagnosing sarcoma with greater sensitivity. This information should be shared with patients.

Objective: Hospital treatment volume affects survival in patients with endometrial cancer;notably, initial treatment at high-volume centers improves survival outcomes. Our study assessed the effect of hospital treatment volume on cost-effectiveness and survival outcomes in patients with endometrial cancer in Japan. Methods: A decision-analytic model was evaluated using the following variables and their impact on cost-effectiveness: 1) hospital treatment volume (low-, intermediate-, and highvolume centers) and 2) postoperative recurrent risk factors based on pathological findings (high- and intermediate-risk or low-risk). Data were obtained from the Japan Society of Obstetrics and Gynecology database, systematic literature searches, and the Japanese Diagnosis Procedure Combination database. Quality-adjusted life years (QALY) was used as a measure of effectiveness. The model was built from a public healthcare perspective and the impact of uncertainty was assessed using sensitivity analyses. Results: A base-case analysis showed that the incremental cost-effectiveness ratio at high-volume centers was below a willingness-to-pay (WTP) threshold of ¥5,000,000with a maximum of ¥3,777,830/4.28 QALY for the high- and intermediate-risk group, and ¥2,316,695/4.57 QALY for the low-risk group. Treatment at the high-volume centers showed better efficiency and cost-effectiveness in both strategies compared to intermediate- or lowvolume centers. Sensitivity analyses showed that the model outcome was robust to changes in input values. With the WTP threshold, treatment at high-volume centers remained cost-effective in at least 73.6% and 78.2% of iterations for high- and intermediate-risk, and lowrisk groups, respectively. Conclusion Treatment at high-volume centers is the most cost-effective strategy for guiding treatment centralization in patients with endometrial cancer.

Objective: Hospital treatment volume affects survival in patients with endometrial cancer;notably, initial treatment at high-volume centers improves survival outcomes. Our study assessed the effect of hospital treatment volume on cost-effectiveness and survival outcomes in patients with endometrial cancer in Japan. Methods: A decision-analytic model was evaluated using the following variables and their impact on cost-effectiveness: 1) hospital treatment volume (low-, intermediate-, and highvolume centers) and 2) postoperative recurrent risk factors based on pathological findings (high- and intermediate-risk or low-risk). Data were obtained from the Japan Society of Obstetrics and Gynecology database, systematic literature searches, and the Japanese Diagnosis Procedure Combination database. Quality-adjusted life years (QALY) was used as a measure of effectiveness. The model was built from a public healthcare perspective and the impact of uncertainty was assessed using sensitivity analyses. Results: A base-case analysis showed that the incremental cost-effectiveness ratio at high-volume centers was below a willingness-to-pay (WTP) threshold of ¥5,000,000with a maximum of ¥3,777,830/4.28 QALY for the high- and intermediate-risk group, and ¥2,316,695/4.57 QALY for the low-risk group. Treatment at the high-volume centers showed better efficiency and cost-effectiveness in both strategies compared to intermediate- or lowvolume centers. Sensitivity analyses showed that the model outcome was robust to changes in input values. With the WTP threshold, treatment at high-volume centers remained cost-effective in at least 73.6% and 78.2% of iterations for high- and intermediate-risk, and lowrisk groups, respectively. Conclusion Treatment at high-volume centers is the most cost-effective strategy for guiding treatment centralization in patients with endometrial cancer.

Objective: Hospital treatment volume affects survival in patients with endometrial cancer;notably, initial treatment at high-volume centers improves survival outcomes. Our study assessed the effect of hospital treatment volume on cost-effectiveness and survival outcomes in patients with endometrial cancer in Japan. Methods: A decision-analytic model was evaluated using the following variables and their impact on cost-effectiveness: 1) hospital treatment volume (low-, intermediate-, and highvolume centers) and 2) postoperative recurrent risk factors based on pathological findings (high- and intermediate-risk or low-risk). Data were obtained from the Japan Society of Obstetrics and Gynecology database, systematic literature searches, and the Japanese Diagnosis Procedure Combination database. Quality-adjusted life years (QALY) was used as a measure of effectiveness. The model was built from a public healthcare perspective and the impact of uncertainty was assessed using sensitivity analyses. Results: A base-case analysis showed that the incremental cost-effectiveness ratio at high-volume centers was below a willingness-to-pay (WTP) threshold of ¥5,000,000with a maximum of ¥3,777,830/4.28 QALY for the high- and intermediate-risk group, and ¥2,316,695/4.57 QALY for the low-risk group. Treatment at the high-volume centers showed better efficiency and cost-effectiveness in both strategies compared to intermediate- or lowvolume centers. Sensitivity analyses showed that the model outcome was robust to changes in input values. With the WTP threshold, treatment at high-volume centers remained cost-effective in at least 73.6% and 78.2% of iterations for high- and intermediate-risk, and lowrisk groups, respectively. Conclusion Treatment at high-volume centers is the most cost-effective strategy for guiding treatment centralization in patients with endometrial cancer.

Objectives: Behavioral restrictions and staying at home during the COVID-19 pandemic have affected lifestyles. It was hypothesized that patients with rheumatoid arthritis (RA) decreased their activities of daily living (ADL) and exercise during the pandemic. The aim of this study is to investigate the changes in lifestyle and body composition. Methods: Data were obtained from an observational study (CHIKARA study). Of 100 RA patients, 70 (57 women, 13 men) were followed-up with measurements of grip strength, as well as muscle mass, fat mass, and basal metabolic rate by a body composition analyzer. Changes in ADL and exercise were evaluated using a visual analog scale. The relationships between changes in ADL or exercise and body composition were investigated. Results: Muscle mass and grip strength were significantly lower after behavioral restrictions compared to the periods before restrictions (34.0 vs 34.7 kg, P < 0.001; 16.2 vs 17.2 kg, P = 0.013, respectively). Fat mass was significantly greater after behavioral restrictions compared to the periods before restrictions (16.2 vs 15.5 kg, P = 0.014). The mean decrease in ADL was 44%, whereas that of exercise was 20%.The change in muscle mass (β = −0.335, P = 0.007) was the only independent factor for the change in exercise on multivariate analysis. Conclusions Muscle mass and grip strength decreased and fat mass increased in RA patients with the behavioral restrictions of the COVID-19 pandemic. Muscle mass decreased in patients without exercise. Maintenance of muscle mass may be important during the COVID-19 pandemic.

Objective: Owing to the potential benefits of minimally invasive hysterectomy for endometrial cancer, the practice pattern has recently shifted in Japan. This study examined the trends in minimally invasive surgery (MIS) in patients with endometrial cancer in Japan. Methods: This retrospective observational study examined the Japan Society of Obstetrics and Gynecology Tumor Registry database between 2015–2019. This study examined the time-specific proportion change and predictors of MIS use in initial endometrial cancer treatment in Japan, and compared it with the use of abdominal surgery. Additionally, the association between hospital surgical treatment volume and MIS use was examined. Results: A total of 14,059 patients (26.5%) underwent minimally invasive hysterectomy, and 39,070 patients (73.5%) underwent abdominal hysterectomy in the study period. Patients who underwent MIS were more likely to be treated at high-volume centers, younger, central, or western Japan residents, registered in recent years, and had a tumor with stage I disease, type 1 histology, and less myometrial invasion (all adjusted p<0.05). The proportion of MIS treatments increased from 19.1% in 2015 to 34.3% in 2019 (p<0.001). On multivariable analysis, treatment at high-volume centers was a contributing factor for MIS (adjusted odds ratio=3.85; 95% confidence interval=3.44–4.30). MIS at high-volume centers increased significantly from 24.8% to 41.0% (p<0.001) during the study period, whereas MIS at low-volume centers remained at median 8.8%. Conclusion MIS has increased significantly in recent years, accounting for nearly 34% of surgical management of endometrial cancer in Japan. High-volume treatment centers take the lead in performing MIS.

Objective: Associations between hospital treatment volume and survival outcomes for women with 3 types of gynecologic malignancies, and the trends and contributing factors for high-volume centers were examined. Methods: The Japan Society of Obstetrics and Gynecology tumor registry databased retrospective study examined 206,845 women with 80,741, 73,647, and 52,457 of endometrial, cervical, and ovarian tumor, respectively, who underwent primary treatment in Japan between 2004 and 2015. Associations between the annual treatment volume and overall survival (OS) for each tumor type were examined using a multivariable Cox proportional hazards model with restricted cubic splines. Institutions were categorized into 3 groups (low-, moderate-, and high-volume centers) based on hazard risks. Results: Hazard ratio (HR) for OS each the 3 tumors decreased with hospital treatment volume. The cut-off points of treatment volume were defined for high- (≥50, ≥51, and ≥27), moderate- (20–49, 20–50, and 17–26), and low-volume centers (≤19, ≤19, and ≤16) by cases/year for endometrial, cervical, and ovarian tumors, respectively. Multivariate analysis revealed younger age, rare tumor histology, and initial surgical management as contributing factors for women at high-volume centers (all, p<0.001). The proportion of high-volume center treatments decreased, whereas low-volume center treatments increased (all p<0.001). Treatment at high-volume centers improved OS than that at other centers (adjusted HR [aHR]=0.83, 95% confidence interval [CI]=0.78–0.88; aHR=0.78, 95% CI=0.75–0.83; and aHR=0.90, 95% CI=0.86–0.95 for endometrial, cervical, and ovarian tumors). Conclusion Hospital treatment volume impacted survival outcomes. Treatments at high-volume centers conferred survival benefits for women with gynecologic malignancies. The proportion of treatments at high-volume centers have been decreasing recently.

Epithelial ovarian cancer remains the lethal gynecological malignancy in women. The representative histotype is high-grade serous carcinoma (HGSC), and most patients with HGSC present at advanced stages with peritoneal dissemination. Since the peritoneal dissemination is the most important factor for poor prognosis of the patients, complete exploration for its molecular mechanisms is mandatory. In this narrative review, being based on the clinical, pathologic, and genomic findings of HGSC, chromosomal instability and epigenetic dynamics have been discussed as the potential drivers for cancer development in the fallopian tube, acquisition of cancer stem cell (CSC)-like properties, and peritoneal metastasis of HGSC. The natural history of carcinogenesis with clonal evolution, and adaptation to microenvironment of peritoneal dissemination of HGSC should be targeted in the novel development of strategies for prevention, early detection, and precision treatment for patients with HGSC.

Objectives: Osteosarcopenia is defined as osteoporosis with sarcopenia. The impacts of osteosarcopenia on falls and fractures in rheumatoid arthritis (RA) patients were investigated using 4 years of data from a longitudinal study (CHIKARA study). Methods: The patients were divided into 4 groups by their baseline status: no sarcopenia and no osteoporosis (SP-OP-); only sarcopenia (SP + OP-); only osteoporosis (SP-OP+); and both sarcopenia and osteoporosis (SP + OP+). Survival rates and Cox hazard ratios were analyzed using falls and fractures as endpoints, adjusted by age, sex, and body mass index. Results: A total of 100 RA patients (SP-OP-: 44%, SP + OP-: 17%, SP-OP+: 28%, and SP + OP+: 11%) were enrolled; 37 patients had falls, and 19 patients had fractures. The fall-free and fracture-free survival rates were significantly lower in SP + OP+ (36.4%, 54.5%) than in SP-OP- (75.0%, 86.4%). The hazard ratio of falls was significantly increased in SP + OP+, by 3.32-fold (95%CI: 1.01–10.9), whereas in SP + OP- and SP-OP+, there were no differences compared to SP-OP-. Conclusions The survival rates with the endpoints of falls and fractures in RA patients with osteosarcopenia were lower during 4-year follow-up. The risk of falls increased with the synergistic effect of osteoporosis and sarcopenia.

Objectives: Sarcopenia is relatively common in rheumatoid arthritis (RA) patients. Thicknesses of the quadriceps muscle and fat are easily measured by ultrasound (US) and are known to be related to skeletal muscle mass and fat mass, respectively. Methods: Eighty-four patients enrolled in the prospective correlation research of sarcopenia, skeletal muscle, and disease activity in rheumatoid arthritis study (UMIN000023744) underwent US examinations of anterior thigh muscle thickness (MT) and fat thickness (FT). Muscle and body fat (BF) mass were also examined by a body composition analyzer. Whether MT and FT were related to sarcopenia and obesity was examined. Results: MT was significantly lower in RA patients with sarcopenia than in those without (23.8 vs 28.2 mm, P ¼ 0.001). MT was related to sarcopenia (men: r ¼ 0.56, P ¼ 0.02, women: r ¼ 0.32, P ¼ 0.01). The cut-off value of MT for sarcopenia was 24.7 mm in men and 19.7 mm in women on receiver operating characteristic curve analyses. FT was correlated with BF percentage (%BF; men: r ¼ 0.66, P < 0.01, women: r ¼ 0.62, P < 0.001), which was estimated by 2.04xFTþ8.53 in men and 1.2xFTþ17.42 in women by a simple linear regression model. This means that FT ! 8.1 mm in men and FT ! 14.6 mm in women indicated obesity. Conclusions US examination of the anterior thigh was useful to detect sarcopenia and obesity in RA patients.