Significance Of Margins Research Articles

Clinical significance of positive resection margin for patients with rectal neuroendocrine tumors within 20 mm following initial endoscopic resection: A multi-center study

BackgroundThe incidence of rectal neuroendocrine tumors (RNETs) has witnessed a significant surge, with a notable proportion being amenable to endoscopic removal. However, the clinical significance of positive resection margin for RNETs patients following endoscopic resection remain unknown, resulting in a lack of consensus regarding the appropriateness of implementing salvage treatment. MethodsIn this large, multicenter, retrospective cohort study, we analyzed the medical records of individuals who underwent endoscopic resection for RNETs and classified them into two groups: the positive resection margin and the negative resection margin group. The overall survival (OS) and disease-free survival (DFS) were compared among two group. The independent variables were identified using univariate and multivariate logistic regression analyses to predict positive resection margin. Then, the model was established to predict the patients with positive resection margin using multivariate logistic regression. Results181 RNETs patients (34.3 %) represented positive margin after endoscopic resection. Following a median follow-up period of 72 months, tumor recurrence manifested in 12 out of 527 patients (2.2 %) and the presence of positive resection margin was associated with worse DFS. Independent factors correlating with positive resection margin included endoscopic resection method choice, RNETs located in the low rectum, NLR >4.44 and tumor size exceeding 14.89 mm. A prediction model was therefore established with high predictive accuracy and excellent clinical applicability determined by calibration curves and DCA curve. Among RNETs patients with positive margin following endoscopic resection, implementing salvage treatment was beneficial for improving DFS and salvage endoscopic resection offer equal efficiency compared with salvage radical resection. ConclusionsPositive resection margin following endoscopic resection may indicate negative prognosis. Salvage treatment can improve the prognosis of RNETs patients with positive resection margin. Notably, salvage local resection exhibited similar efficacy compared with radical surgery in term of survival benefit.

Prognostic significance of involvement of the circumferential resection margin/surface in patients with pancreatic head cancer: A prospective evaluation of pancreatoduodenectomy specimens using the 0 and 1 mm rules

Background/ObjectivesThe prognostic significance of circumferential resection margin (CRM) or circumferential surface (CS) in pancreatic head cancer is controversial. We investigated the survival outcomes according to CRM or CS involvement in pancreatoduodenectomy specimens of pancreatic ductal adenocarcinoma (PDAC). MethodsA total of 102 pancreatoduodenectomy specimens after upfront surgery for PDAC between 2014 and 2018 were prospectively collected. The superior mesenteric vein/portal vein or superior mesenteric artery margins were classified as CRM, and the anterior or posterior surfaces as CS. Survival outcomes and recurrence were compared according to the CRM/CS status, which was categorized into R10mm, R11mm, and R0 (≥1 mm) by the 0 and 1 mm rules. ResultsFor CRM, R10mm had significantly lower overall survival (OS) (P < 0.001) and disease-free survival (P < 0.001) rates than R11mm and R0, with no difference between R11mm and R0. For CS, R0 had a significantly higher OS rate (P < 0.001) than R10mm and R11mm, with no difference between R10mm and R11mm. In multivariable analysis, R10mm CRM was an independent risk factor for OS (hazard ratio 2.410, P = 0.003) and DFS (hazard ratio 5.019, P < 0.001). When CRM/CS were analyzed separately, only the R10mm superior mesenteric artery margin was significantly associated with local recurrence (P = 0.012). ConclusionsThe results suggest that CRM involvement defined by the 0 mm rule is more appropriate than the 1 mm rule for predicting survival outcomes, but CS involvement defined by the 0 or 1 mm rules is not prognostically significant.

Impact of Positive Resection Margins on Recurrence and Survival Following Resection and Adjuvant Chemotherapy in Pancreatic Cancer: Results of the PRODIGE 24-CCTG PA-6 Randomized Controlled Trial.

This study investigated the correlation between positive resection margins and outcomes in patients with pancreatic ductal adenocarcinoma who underwent surgery and adjuvant chemotherapy according to the pivotal trial PRODIGE 24-CCTG PA-6. The primary focus is on elucidating the prognostic significance of specific resection margins, including those associated with the superior-mesenteric vein (SMV), medial, and posterior pancreas. The analysis involved 400 patients across multiple centers in France and Canada. Surgical resection and subsequent adjuvant chemotherapy were core interventions. This study assessed the prognostic impact of resection margins, highlighting the significance of standardized pathology assessments. Additionally, the influence of chemotherapy regimen choice, comparing gemcitabine to mFOLFIRINOX, on the implications of positive resection margins was examined. Only three margins, SMV (HR=1.48 95% CI [1.11;1.96], P<.001), medial (HR=1.92 95% CI [1.36;2.73], P<.001) and posterior (HR=1.65 95% CI [1.21;2.24], P=.002), had a significant prognostic impact on disease-free survival and were sufficient compared with the seven recommended margins (Kappa=0.90 95% CI [0.87; 0.94]). R1 status was significant independent prognostic factor for poorer survival in gemcitabine-treasted patients (HR=1.97 95% CI [1.23;3.16], P=.005) but lost its significance with mFOLFIRINOX (HR=1.46 95% CI [0.91;2.35], P=.114). All efforts should be made to evaluate the three margins of the highest prognostic value, with the others being secondary. A key finding of this study is the likely effect of mFOLFIRINOX on local invasion in operated patients, which seems to correct the impairment related to margin involvement, probably explaining the improvements in DFS and OS.

Clinical outcomes of colorectal neoplasm with positive resection margin after endoscopic submucosal dissection

A positive resection margin after colorectal endoscopic submucosal dissection (ESD) is associated with an increased risk of recurrence. We aimed to identify the clinical significance of positive resection margins in colorectal neoplasms after ESD. We reviewed 632 patients who had en bloc colorectal ESD at two hospitals between 2015 and 2020. The recurrence rates and presence of residual tumor after surgery were evaluated. The rate of additional surgery after ESD and recurrence rate were significantly higher in patients with incomplete resection (n = 75) compared to patients with complete resection (n = 557). When focusing solely on non-invasive lesions, no significant differences in recurrence rates were observed between the groups with complete and incomplete resection (0.2% vs. 1.9%, p = 0.057). Among 84 patients with submucosal invasive carcinoma, 39 patients underwent additional surgery due to non-curative resection. Positive vertical margin and lymphovascular invasion were associated with residual tumor. Lymphovascular invasion was associated with lymph node metastasis. However, no residual tumor nor lymph node metastases were found in patients with only one unfavorable histological factor. In conclusion, a positive resection margin in non-invasive colorectal lesions, did not significantly impact the recurrence rate. Also, in T1 colorectal cancer with a positive vertical resection margin, salvage surgery can be considered in selected patients with additional risk factors.

Impact of dysplasia at resection margin on oncologic outcome after curative resection of oral tongue squamous cell carcinoma: significance of high-grade dysplastic resection margin.

This study aimed to compare the oncologic outcomes among negative, close, positive, and dysplasia resection margins (RMs) with oral tongue squamous cell carcinoma (OSCC) and to investigate the impact of dysplastic RMs. The 565 patients were retrospectively analyzed and divided into four groups according to RM. Dysplasia was classified into mild, moderate, and severe subgroups. RMs consisted of negative (62.1%), close (27.1%), positive (2.1%), and dysplastic (8.7%). In multivariate analysis, advanced T/N stages and positive RM were significant risk factors for overall survival, while dysplasia at the RM was not a significant risk factor for locoregional recurrence or overall survival. In subgroup analysis of patients with dysplastic margin, RM with severe dysplasia showed higher recurrence than mild and moderate dysplasia. Dysplastic RM was not a risk factor for recurrence and survival. Severe dysplasia RM should be carefully observed due to higher recurrence compared to other dysplasia RMs.

Assessing pentafecta outcomes post radical cystectomy: A tertiary care center study.

Bladder cancer is a common and serious disease globally, often requiring radical cystectomy as the preferred treatment. However, this procedure carries substantial risks and complications. To evaluate its success, pentafecta, a five-component measure, was introduced. This study investigates the attainment of pentafecta following radical cystectomy and examines factors that influence its achievement. This retrospective, single-group study was conducted at AIIMS Jodhpur. The study population included 42 patients who underwent radical cystectomy for bladder cancer. Various data, including demographic characteristics, clinical features, surgical techniques, and postoperative outcomes, were collected from medical records. The primary outcome measure was the rate of achieving pentafecta, which comprises five parameters. Out of 42 patients, 26 (61.9%) achieved pentafecta. Age, gender, comorbidities and surgical approach did not significantly affect the attainment of pentafecta. Negative surgical margins were achieved in 95.2% of cases, and adequate lymph node dissection (>16 lymph nodes) was performed in 85.7% of cases. The absence of Clavien-Dindo grade 3-5 complications and recurrence was observed in 80.9% and 90.47% of cases, respectively. Uretero-enteric stricture was absent in 95.2% of cases. The study emphasizes the significance of negative surgical margins, thorough lymph node dissection, absence of complications, recurrence, and uretero-enteric strictures in evaluating the success of radical cystectomy as pentafacta outcomes. Patients with higher drain output and wound infections are less likely to achieve pentafacta outcome and indicates poorer outcome. By considering these factors, clinicians can assess patient outcomes and identify areas for improvement.

Prognostic value of circumferential radial margin involvement in esophagectomy for esophageal cancer: a case series.

Residual tumor at the proximal or distal margin after esophagectomy is associated with worse survival outcomes; however, the significance of the circumferential resection margin (CRM) remains controversial. In this study, we sought to evaluate the prognostic significance of the CRM in patients with esophageal cancer undergoing resection. We identified patients who underwent esophagectomy for pathologic T3 esophageal cancer from 2000 to 2019. Patients were divided into three groups: CRM- (residual tumor >1mm from the CRM), CRM-close (residual tumor >0 to 1mm from the CRM), and CRM+ (residual tumor at the surgical CRM). CRM was also categorized and analyzed per the Royal College of Pathologists (RCP) and College of American Pathologists (CAP) classifications. Of the 519 patients included, 351 (68%) had CRM-, 132 (25%) had CRM-close, and 36 (7%) had CRM+. CRM+ was associated with shorter disease-free survival [DFS; CRM+ vs. CRM-: hazard ratio (HR), 1.53 [95% CI, 1.03-2.28]; P =0.034] and overall survival (OS; CRM+ vs. CRM-: HR, 1.97 [95% CI, 1.32-2.95]; P <0.001). Survival was not significantly different between CRM-close and CRM-. After adjustment for potential confounders, CAP+ was associated with poor oncologic outcomes (CAP+ vs. CAP-: DFS: HR, 1.47 [95% CI, 1.00-2.17]; P =0.050; OS: HR, 1.93 [95% CI, 1.30-2.86]; P =0.001); RCP+ was not (RCP+ vs. RCP-: DFS: HR, 1.21 [95% CI, 0.97-1.52]; P =0.10; OS: HR, 1.21 [95% CI, 0.96-1.54]; P =0.11). CRM status has critical prognostic significance for patients undergoing esophagectomy: CRM+ was associated with worse outcomes, and outcomes between CRM-close and CRM- were similar.

The prognostic significance of surgical resection margins for local recurrence, distant metastasis, and overall survival in sarcoma.

Surgical resection with microscopically negative margins constitutes one of the key elements of a curative therapeutic approach for localized sarcomas. However, the prognostic value of quantitative margin width remains controversial. We sought to determine the prognostic significance of margin status and margin width for local recurrence (LR), distant recurrence (DR), and overall survival. Retrospective analysis of 210 patients undergoing resection of localized sarcoma between 1997 and 2018 at a national sarcoma reference center. Logistic regression did not reveal an effect of metric margin width as a prognostic factor for LR (odds ratio [OR] = 0.98, p = 0.574), DR (OR = 1, p = 0.908), or overall survival (hazard ratio = 0.98, 95% confidence interval = 0.73-1.20, p = 0.609). Subgroup analysis revealed no differences between complete first resections (R0) and re-resections (re-R0) following unplanned R1-resections for LR (p = 0.727) and overall survival (p = 0.125), but a significantly higher DR-rate in re-R0 cases (p = 0.022). Achieving a negative margin is essential in sarcoma surgery, however, metric margin width was not associated with disease-specific outcomes. Re-resection of unplanned R1-resections should be performed to control for LR and overall survival rates. As re-R0 cases were at significantly higher risk of DR, these patients should be followed up closely in standardized surveillance protocols.

Kyōkaisen no gakkōshi: Sengo nihon no gakkōka shakai no shūen to shūhen (Boundaries of Japanese Public Education: A History of Schooling Society and Its Borders)

As its title suggests, this volume is composed of chapters on areas and aspects of the schooling system of postwar Japan that are often regarded as peripheral. The book seeks not only to illuminate its topics, but also to examine the nature and significance of margins and borders in the school system. Edited by one of Japan’s leading historians of education, it sheds light on to aspects of schooling that will be less familiar to many and provides a valuable way to consider these topics. The main focus of the book is the period from the late 1940s to the early 1970s. The book begins with two chapters by editor Kimura Hajime. In the introduction, Kimura explores the concepts that run through the book, pointing out that ‘boundaries’ can relate to the school system or to schooling practices—though system and practices exist in relation to one another. One key boundary is constituted by the term ‘ichijōkō’ (literally, ‘article one school’), referring to the types of school mentioned in the first article of Japan’s School Education Law. Kimura points out that although ichijōkō tend to be seen as the core of the postwar school system, even within this core there is a periphery, while schools that are not ichijōkō have also played highly significant roles. Furthermore, the boundaries of the ‘core’ and the ‘periphery’ have shifted over time in terms of both systems and practices. In chapter 1, Kimura goes on to give a valuable overview of the development of schooling in Japan from the later Meiji period to the present. This part is particularly useful for its references to the latest Japanese scholarship.

Prognostic significance of extra-nodal extension and positive surgical margins in HPV positive oropharyngeal squamous cell carcinoma

BackgroundWhether extra-nodal extension (ENE+) and surgical margin positivity (margin+) are poor prognostic factors in HPV-associated (HPV+) oropharyngeal carcinoma (OPC) remains uncertain. ResultsOur study evaluated if microscopic ENE+ and/or margin+ are associated poorer recurrence free survival (RFS) and overall survival (OS) in HPV+ OPC. Patients were classified as high risk (ENE+ and/or margin+) or low risk (ENE- and margins-). Of a total of 176 patients HPV+ OPC, 81 underwent primary surgery and dad data on ENE and margin status. There was no statistically significant difference in RFS (p = 0.35) or OS (p = 0.13) for high-risk versus low-risk groups. Ongoing smoking (p = 0.023), alcohol use (p = 0.044) and advanced stage (p = 0.019) were associated with higher risk of recurrence. Only advanced stage (p-value <0.0001) was associated poorer overall survival. ConclusionsThe presence of ENE+ and/or margin+ was not an independent predictor of poor RFS or OS in HPV+ OPC.

Prognostic Significance of the Proximal Margin for Esophagogastric Junction Adenocarcinoma with Type II and III Tumors after Surgery

Background: The incidence of Esophagogastric Junction Adenocarcinoma (EJA) has increased in recent years, with surgical resection the main choice of treatment. The optimal length of the proximal margin for EJA is still under debate, and the impact of EJA survival and recurrence remains unclear. The aim of the present study was to investigate the influence of the optimal length of the proximal margin on EJA. Methods: From January 2011 to December 2015, 131 patients who had EJA with type II tumors were included and retrospectively analyzed. All patients underwent radical R0 resection. The proximal margin was measured promptly after resection, and the frozen-section pathological examination was negative for the margin. Results: There were 3 cases of Siewert type I EJA (2.9%), 75 cases of Siewert type II EJA (57.9%), and 53 cases (40.1%) of Siewert type III EJA. The median number of lymph nodes examined was 19 (range: 1-41), and the median number of positive lymph nodes was 2 (range: 0–18). Sixty-three patients underwent total gastrectomy (48.1%), and 68 underwent proximal gastrectomy (51.9%). The median follow-up time was 57.3 months: (range 1.9–174.1); 34 patients (26%) relapsed and 74 (56.5%) died. The 5-year overall survival rate of type II tumor patients was 68.2%, and that of type III tumor patients was 38.5% (P=0.02). For patients with a proximal margin &lt;2cm, the median recurrence time was 41.6 months, whereas it was for 42.8 months for patients with proximal margin &gt;2cm (log–rank: 0.496). Our data analysis found that a proximal margin length of 2cm was a prognostic variable for type II and type III tumors. Conclusions: There are a number of factors associated with recurrence and overall survival at 5 years for patients who have EJA with type II and type III tumors, and a proximal margin &gt;2cm may indicate better prognosis.

The significance of margins in pediatric Non-Rhabdomyosarcoma soft tissue sarcomas: Consensus on surgical margin definition harmonization from the INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT).

Margin status following surgery in children, adolescents, and young adults with soft tissue sarcomas is controversial and has been defined differently by various specialties, with definitions changing over time and by cooperative group. The International Soft Tissue Sarcoma Consortium (INSTRuCT) is a collaboration of the Children's Oncology Group (COG) Soft Tissue Sarcoma Committee, European pediatric Soft Tissue sarcoma Study Group (EpSSG), and the European Cooperative Weichteilsarkom Studiengruppe (CWS) devoted to improving patient outcomes by pooling and mining cooperative group clinical trial data. The INSTRuCT non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) working group aimed to develop international harmonized recommendations regarding surgical margin assessment and definitions in children and adolescents with soft tissue tumors. This review addresses accepted principles and areas of controversy, including the perspectives of surgeons, pathologists, radiation oncologists, and pediatric oncologists, to develop a framework for building common guidelines for future research.

Evaluation of resection margins in oral squamous cell carcinoma.

Surgery is the primary treatment modality for oral squamous cell carcinoma. The purpose of the surgical procedure is complete removal of the tumor with asufficient margin of healthy tissue in its surroundings. Resection margins represent an important factor for planning further treatment and for estimation of the disease prognosis. Resection margins can be divided into negative, close and positive. Positive resection margins are considered aprognostically unfavorable factor. However, the prognostic significance of close resection margins is not entirely clear. The aim of this study was to evaluate the relationship between resection margins and disease recurrence, disease-free survival and overall survival. The study included 98 patients who underwent surgery for oral squamous cell carcinoma. During histopathological examination, resection margins of each tumor were evaluated by apathologist. The margins were divided into negative (&gt; 5 mm), close (0-5 mm), and positive (0 mm). Disease recurrence, disease-free survival and overall survival were evaluated according to the individual resection margins. Disease recurrence occurred in 30.6% of patients with negative, 40.0% with close, and 63.6% with positive resection margins. Significantly shorter disease-free survival and shorter overall survival in patients with positive resection margins was proven. The five-year survival rate was 63.9% in patients with negative, 57.5% with close, and only 13.6% with positive resection margins. The risk of death was 3.27times higher in patients with positive resection margins compared to patients with negative resection margins. Positive resection margins represent anegative prognostic factor, which was also confirmed in our study. There is no unequivocal consensus on the definition of close and negative resection margins and also on the prognostic significance of close resection margins. Factors that may contribute to inaccuracy in the evaluation of resection margins include tissue shrinkage after excision and after fixation of specimens before the histopathological examination. Positive resection margins were associated with asignificantly higher incidence of disease recurrence, shorter disease-free survival and shorter overall survival. When comparing the incidence of recurrence, disease-free survival, and overall survival between patients with close and negative resection margins, the differences were not statistically significant.

LIQUIDITY RISK AND FACTORS DETERMINANT: A CASE STUDY ON ISLAMIC RURAL BANKING IN INDONESIA

To maintain public trust, a bank should hold a liquidity risk. The study aims to analyze the internal factors that affect liquidity risk in Islamic rural banks in Indonesia. The banks have a more complicated liquidity management than conventional banks due to the application of sharia law in the banks. Islamic rural bank liquidity risk is measured by the financing-to-deposit ratio. The internal factors are the capital adequacy ratio, non-performing financing, return on assets, operating expenses to income ratio, third-party funds, and the type of financing consisting of profit margin financing and profit-sharing financing. This study uses 100 Islamic rural banks as a sample. The data span from 2018Q1 to 2021Q4. The analysis was conducted by estimating and testing panel regression models. The estimation results of the chosen fixed-effect model show a positive effect of profit margin financing and negative effects of capital adequacy ratio, non-performing financing, and profit-sharing financing on the dependent variable. It also finds that return on assets, operating expenses to income ratio, and third-party funds have no significant impact on the dependent variable. Recall that the cost is the difference between return and profit. The novelty of this paper is as follows. With the significance of profit margin and the insignificance of return, it can be inferred the cost of bank operation matter for the bank liquidity risk. With the significance of profit sharing financing and the accompanied non-performing financing, the study also suggests that shariah principles in the bank operation matter for the bank’s liquidity risk. Keywords: Liquidity Risk, Islamic Rural Bank, Financing-to-Deposit Ratio DOI： https://doi.org/10.35741/issn.0258-2724.58.1.27

Epidemiology and significance of surgical margins in the management of HPV-associated vulvar precancers (H-SIL) - analysis of own data.

Epidemiology and evaluation of the importance of surgical margins in the treatment of vulvar H-SIL - analysis of own data. The prospective study included women dia-gnosed with HPV-associated vulvar epithelial neoplasia from 10/2016 to 1/2022. A total of 65 women were included. After surgical treatment, the women were distributed to groups according to surgical margins and were followed-up at regular intervals. Seventeen women (26%) dia-gnosed with HPV-associated vulvar intraepithelial neoplasia were under 49 years, whereas 48 women (74%) were older than 49 years. Recurrence rates of HPV-associated precancers were 12.3%, 1.5% and 3.1% in excisions with positive margins up to 1mm peripheral margins and 1-3mm peripheral margins, respectively. The risk of recurrence when the lesion reaches the margin is statistically significant, compared to a healthy margin of 1-3mm. Keeping the minimal healthy margin (1-3mm) seems to be an acceptable risk of recurrence of HPV-associated vulvar intraepithelial neoplasia with positive cosmetic effect and minimal risk of disturbing the psychosexual functions of women. Long-term regular follow-up is necessary.

The Clinical Significance of the Positive Surgical Margin and Dominant Tumor Laterality Following Radical Prostatectomy: A Retrospective Study

Background and objectivesPositive surgical margin (PSM) after radical prostatectomy (RP) is an established factor associated with the outcome of biochemical recurrence (BCR). Dominant tumor is presumed to harbor the most aggressive biological behavior. The aim of this study was to evaluate the clinical significance of the PSM laterality and its correlation with dominant tumor.

The prognostic significance of the circumferential resection margin in esophageal squamous cell carcinoma patients without neoadjuvant treatment

BackgroundCircumferential resection margin (CRM) is very important in esophageal cancer, but its diagnostic criteria has not been unified. The College of American Pathologists (CAP) and the Royal College of Pathologists (RCP) provide two different criteria. The aim of this study is to evaluate the long-term prognostic significance of CRM status with different CRM criteria in esophageal squamous cell carcinoma (ESCC).MethodsInfluence of CRM status according to the CAP and RCP criteria on long-term survival of 838 patients with resected pT3 tumors and without neoadjuvant therapy was analyzed. Patients stratified into three groups on the basis of tumor distance from the CRM (CRM > 1 mm, 0-1 mm, and 0 mm) were also analysed.ResultsPositive CRM was found in 59 (7%) patients according to the CAP criteria and 317 (37.8%) patients according to the RCP criteria. Univariate and multivariate survival analysis showed that CRM status, according to three different criteria, was independent prognostic factor. However, subgroup analysis showed that the prognostic value of CRM status was limited to certain metastatic lymph node load. In pN0 subgroup, patients with CRM > 1 mm had better prognosis than patients with CRM 0-1 mm. Patients with CRM 0 mm had worse outcome than patients with CRM > 0 mm in pN1-2 subgroup. But CRM status had no prognosis value in pN3 subgroup.ConclusionsThe CRM status is an important prognostic factor in ESCC patients, but this effect was limited to patients without or with less lymph node metastasis (pN0-2). In clinical practice, we recommend the 1 mm-three-tier criteria as it provides more prognostic value than the traditional two-tier criteria.

Clinicopathological Significances of Positive Surgical Resection Margin after Radical Prostatectomy for Prostatic Cancers: A Meta-Analysis.

Background and Objectives: This study aims to elucidate the positive rate and the clinicopathological significance of surgical margin after radical prostatectomy (RP) through a meta-analysis. Materials and Methods: This meta-analysis finally used 59 studies, including the information about the positive surgical margin (PSM) and those clinicopathological significances after RP. The subgroup analysis for the estimated rates of PSM was evaluated based on types of surgery, grade groups, and pathological tumor (pT) stages. We compared the clinicopathological correlations between positive and negative surgical margins (NSM). Results: The estimated PSM rate was 25.3% after RP (95% confidence interval [CI] 21.9–29.0%). The PSM rates were 26.0% (95% CI 21.5–31.1%) 28.0% (95% CI 20.2–37.5%) in robot-assisted RP and nerve-sparing RP, respectively. The PSM rate was significantly higher in high-grade groups than in low-grade groups. In addition, the higher pT stage subgroup had a high PSM rate compared to the lower pT stage subgroups. Patients with PSM showed significantly high PSA levels, frequent lymphovascular invasion, lymph node metastasis, and extraprostatic extension. Biochemical recurrences (BCRs) were 28.5% (95% CI 21.4–36.9%) and 11.8% (95% CI 8.1–16.9%) in PSM and NSM subgroups, respectively. Patients with PSM showed worse BCR-free survival than those with NSM (hazard ratio 2.368, 95% CI 2.043–2.744%). Conclusions: Our results showed that PSM was significantly correlated with worse clinicopathological characteristics and biochemical recurrence-free survival. Among the results in preoperative evaluations, grade group and tumor stage are useful for the prediction of PSM.

Quantifying Resilience of Wide-Area Damping Control Against Cyber Attack Based on Switching System Theory

Since the cyber attack on the communication network will deteriorate the performance of wide-area damping controllers (WADCs) or even cause instability, many resilient WADCs are developed to mitigate the adverse influence of cyber attacks recently. However, there is a lack of quantitative indexes to guide the controller design in order to achieve the trade-off between attack resilience and damping performance. To address this problem, an index is proposed to quantify the strongest attack that the power system with a given WADC can tolerate, which is called as resilience margin. Firstly, the power system with a WADC subjected to cyber attack is modeled as a switching system consisting of stable and unstable subsystems. Then, based on switching system theory, the definition of resilience margin is presented. To calculate the resilience margin, the Lyapunov stability analysis is implemented on the switching power system to derive a practical calculation algorithm, which combines the bisection method and the linear matrix inequalities (LMIs) technology. The case study on the 16-machine 68-bus system with a voltage source converter based high voltage direct current system is performed. Simulation results demonstrate the effectiveness of the calculation algorithm and the significance of the resilience margin in the design of WADC.

Prognostic significance of surgical margins in pancreatic head cancer - Is the 1 mm R status more predictive than the 0 mm R status? –

Hee Ju SOHN, Hongbeom KIM, Mirang LEE, Hyeong Seok KIM, Youngmin HAN, Wooil KWON, Jun Suh LEE, Yoo-Seok YOON, Ho-Seong HAN, Chang Sup LIM, Jin-Young JANG*. Ann Hepatobiliary Pancreat Surg 2022;26:S83. https://doi.org/10.14701/ahbps.2022S1.OP-4-2