Survival outcomes used to validate version 9 of the American Joint Committee on Cancer staging system for appendiceal cancer.

The standard for cancer staging in the United States for all cancer sites, including primary carcinomas of the appendix, is the American Joint Committee on Cancer (AJCC) staging system. AJCC staging criteria undergo periodic revisions, led by a panel of site-specific experts, to maintain contemporary staging definitions through the evaluation of new evidence. Since its last revision, the AJCC has restructured its processes to include prospectively collected data because large data sets have become increasingly robust and available over time. Thus survival analyses using AJCC eighth edition staging criteria were used to inform stage group revisions in the version 9 AJCC staging system, including appendiceal cancer. Although the current AJCC staging definitions were maintained for appendiceal cancer, incorporating survival analysis into the version 9 staging system provided unique insight into the clinical challenges in staging rare malignancies. This article highlights the critical clinical components of the now published version 9 AJCC staging system for appendix cancer, which (1) justified the separation of three different histologies (non-mucinous, mucinous, signet-ring cell) in terms of prognostic variance, (2) demonstrated the clinical implications and challenges in staging heterogeneous and rare tumors, and (3) emphasized the influence of data limitations on survival analysis for low-grade appendiceal mucinous neoplasms.

Overall Survival is More Closely Associated with Peritoneal than Primary Appendiceal Pathological Grade in Pseudomyxoma Peritonei with Discordant Pathology.

BACKGROUND: The WHO classification of mucinous appendix neoplasms and pseudomyxoma peritonei (PMP) describes low- and high-grade histology and is of prognostic importance. The metastatic peritoneal disease grade can occasionally be different from the primary appendix tumor. This analysis aimed to report outcomes from a high-volume center in patients with pathological discordance. METHODS: This was a retrospective analysis of prospective data of patients treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP at a single institution between January 2016 and December 2020. Reporting was by pathologists with a special interest in peritoneal malignancy. Discordant pathology was classified as a low-grade primary appendix tumor with high-grade peritoneal disease, or a high-grade primary appendix tumor with low-grade peritoneal disease. Outcomes analyzed were overall and recurrence-free survival, and Kaplan-Meier survival curves and the log-rank test were used to analyze the outcomes. RESULTS: Between 2016 and 2020, 830 patients underwent CRS and HIPEC for PMP, of whom 37 (4.4%) had discordant pathology. The primary appendix tumors were low-grade in 23 patients and high-grade in 14 patients. The median Peritoneal Cancer Index (PCI) was significantly higher in patients with a low-grade primary tumor (31 vs. 16; p = 0.001), while complete cytoreduction (CC0/1) was achieved in 31/37 (83.8%) patients. The median follow-up was 19 months. Overall survival was worse in those with high-grade peritoneal disease (p = 0.029), whereas recurrence-free survival was similar in both groups (p = 0.075). CONCLUSION: In PMP with pathological discordance, the peritoneal disease grade influences prognosis and survival.

Estimating the Prevalence of Pseudomyxoma Peritonei in Europe Using a Novel Statistical Method.

BACKGROUND: The determination of the incidence and prevalence of rare diseases is important for economists and health-care providers. Pseudomyxoma peritonei (PMP) is a rare, slow-growing abdominal cancer that represents a substantial burden on both patients and health-care systems. The incidence rate was previously approximated at 1-2 people per million per year; this incidence has never been challenged, and the prevalence has not been estimated. METHODS: Epidemiological data from Norway and England were obtained and analysed to calculate a minimum incidence rate based on the number of patients having a first surgical intervention for PMP. A novel method was then used to determine a prevalence rate for PMP, incorporating incidence, death, and cure rates in a multi-year analysis that accounted for the increasing population of Europe over a 10-year period. RESULTS: An incidence rate of 3.2 people per million per year was calculated, with a corresponding estimated prevalence rate of 22 people per million per year. By this calculation, 11,736 people in Europe were estimated to be living with PMP in 2018. CONCLUSION: Incidence and prevalence are essential tools for assessment of the financial and human cost of a disease. For rare diseases, such as PMP, the lack of accurate registries presents a particular challenge in determining such health-related statistical parameters. Based on our calculations, a significant number of people are living with PMP in Europe, underlining the need for appropriate resource allocation to ensure that adequate health-care measures are provided.

Managing Recurrent Pseudomyxoma Peritonei in 430 Patients After Complete Cytoreduction and HIPEC: A Dilemma for Patients and Surgeons.

BACKGROUND: Epithelial appendiceal neoplasms are uncommon peritoneal malignancies causing a spectrum of disease including pseudomyxoma peritonei (PMP). The optimal management is cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Despite complete CRS (CCRS), recurrence develops in almost 45% of patients. No consensus exists for the optimal treatment of recurrent disease, with treatment strategies including repeat CRS, watch-and-wait, and palliative chemotherapy. This report aims to describe evolving management strategies for a large cohort with recurrence after CCRS. METHODS: This retrospective study analyzed a prospective database of patients with recurrence after CCRS for appendiceal neoplasms from 1994 to 2017 who had long-term follow-up evaluation with tumor markers and computed tomography (CT). RESULTS: Overall, 430 (37.6%) of 1145 PMP patients experienced recurrence at a median of 19 months. Of these 430 patients 145 (33.7%) underwent repeat CRS, 119 (27.7%) had a watch-and-wait approach, and 119 (27.7%) had palliative chemotherapy. The patients with recurrence had a median overall survival (OS) of 39 months, a 3-year survival of 74.6%, a 5-year survival of 57.4%, and a 10-year survival of 36.5%. In the multivariate analysis, the patients who had recurrence within 1 year after primary CRS (hazard ratio [HR], 3.55), symptoms at recurrence (HR, 3.08), a high grade of disease or adenocarcinoma pathology (HR, 2.94), signet ring cells (HR, 1.91), extraperitoneal metastatic disease (HR, 1.71), or male gender (HR, 1.61) had worse OS. The OS was longer for the patients who had repeat CRS (HR, 0.41). The patients who underwent repeat CCRS had a 3-year OS of 87.5%, a 5-year OS of 78.1%, and a 10-year OS of 67.9%. CONCLUSIONS: Dilemmas persist around the optimal management of patients with recurrence after CRS and HIPEC for appendiceal tumors. Selected patients benefit from repeat CRS, particularly those with favorable tumor biology and focal disease.

Patients undergoing cytoreductive surgery for peritoneal malignancy of appendiceal origin should be consented for umbilical excision as 30% have umbilical infiltration.

AIM: Cytoreductive surgery (CRS) for peritoneal malignancy has traditionally included umbilical excision with no published evidence on the incidence of umbilical involvement. The primary aim of this work was to determine the incidence of umbilical involvement in patients undergoing CRS for peritoneal malignancy of appendiceal origin. The secondary aim was to investigate the relationship of umbilical involvement with prior surgery affecting the umbilicus, such as diagnostic laparoscopy and midline laparotomy. METHOD: This study is from a national referral centre in the United Kingdom for appendiceal tumours and peritoneal malignancy. It is a retrospective analysis from a dedicated prospective database. We evaluated the most recent 200 consecutive patients who underwent CRS for peritoneal malignancy of appendiceal origin where all pathology specimens were reported by a recognized expert pathologist in appendiceal tumours and peritoneal malignancy. RESULTS: From June 2016 to September 2019, 200 consecutive patients had CRS and 178 had umbilical excision. Of these 54/178 (30.3%) had disease involving the umbilicus. The pathological findings in the 178 patients were low-grade mucinous carcinoma peritonei in 90/178 (50.6%), high-grade mucinous carcinoma peritonei in 31/178 (17.4%), metastatic appendiceal adenocarcinoma in 29/178 (16.4%) and diffuse acellular mucin in 28/178 (15.7%). Umbilical involvement was found in 25/90 (27.8%) with low-grade, 11/31 (35.5%) with high-grade, 8/29 (27.6%) with adenocarcinoma and 10/28 (35.7%) of patients with acellular mucin. In the 54 patients with umbilical disease, 30/54 (55.6%) had previous diagnostic surgery affecting the umbilicus. In the 124 patients without umbilical disease, 76/124 (61.2%) had prior surgery involving the umbilicus. The difference between the groups was not significant (p = 0.24). CONCLUSION: In patients with peritoneal malignancy of appendiceal origin, approximately 30% have umbilical involvement, irrespective of the primary appendiceal pathology. Umbilical involvement was not associated with prior surgery involving the umbilicus. This is the first report to document the incidence of umbilical pathology and supports consideration of routine umbilical excision in CRS for peritoneal malignancy.

Complicated appendiceal diverticulosis versus low-grade appendiceal mucinous neoplasms: a major diagnostic dilemma.

AIMS: To research and identify how often complicated diverticular disease of the appendix [appendiceal diverticular disease (ADD)] shows histological mimicry of low-grade appendiceal mucinous neoplasms (LAMNs) and to provide guidance on the useful histopathological features that allow the appropriate diagnosis to be made. METHODS AND RESULTS: Seventy-four cases of complicated appendiceal diverticular disease were identified from two specialist centres. Of the second opinion/consultation cases, 71% of the ADD cases had been diagnosed by referring pathologists as LAMNs. Salient pathological features were identified and agreed upon to reach the applicable diagnosis. For a diagnosis of complicated diverticulosis, particularly when associated with mucus cysts, the following morphological features were regarded as important: relative retention of the normal mucosal architecture with lamina propria and a maintained crypt architecture, crypts arranged in regular array, epithelial hyperplasia and a lack of nuclear abnormalities extending the length of the crypts. In a formal case-control study undertaken on 30 cases with each diagnosis, ADD and LAMN, loss of lamina propria, a filiform architecture and hypermucinosis were significantly associated with low-grade appendiceal mucinous neoplasms. Mucosal neuromas were significantly associated with diverticular disease of the appendix. CONCLUSIONS: To our knowledge, this study represents the largest series in the world literature and serves to highlight the important pathological features to distinguish complicated diverticular disease of the appendix from LAMNs, and emphasises the difficulties experienced by diagnostic pathologists in diagnosing complicated appendiceal diverticulosis. This is important, as LAMNs have a significant risk of transcoelomic spread, while complicated appendiceal diverticulosis has no such risk.

Reproducibility of the peritoneal regression grading score for assessment of response to therapy in peritoneal metastasis.

AIMS: The four-tiered peritoneal regression grading score (PRGS) assesses the response to chemotherapy in peritoneal metastasis (PM). The PRGS is used, for example, to assess the response to pressurised intraperitoneal aerosol chemotherapy (PIPAC). However, the reproducibility of the PRGS is currently unknown. We aimed to evaluate the inter- and intraobserver variability of the PRGS. METHODS AND RESULTS: Thirty-three patients who underwent at least three PIPAC treatments as part of the PIPAC-OPC1 or PIPAC-OPC2 clinical trials at Odense University Hospital, Denmark, were included. Prior to each therapy cycle, peritoneal quadrant biopsies were obtained and three haematoxylin and eosin (H&E)-stained step sections were scanned and uploaded to a pseudonymised web library. For determining interobserver variability, eight pathologists assessed the PRGS for each quadrant biopsy, and Krippendorff's alpha and intraclass correlation coefficients (ICCs) were calculated. For determining intraobserver variability, three pathologists repeated their own assessments and Cohen's kappa and ICCs were calculated. A total of 331 peritoneal biopsies were analysed. Interobserver variability for PRGS of each biopsy and for the mean and maximum PRGS per biopsy set was moderate to good/substantial. The intraobserver variability for PRGS of each biopsy and for the mean and maximum PRGS per biopsy set was good to excellent/almost perfect. CONCLUSIONS: Our data support the PRGS as a reproducible and useful tool to assess response to intraperitoneal chemotherapy in PM. Future studies should evaluate the prognostic and predictive role of the PRGS.

Outcomes of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma and predictors of survival.

BACKGROUND: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) benefits selected patients with peritoneal mesothelioma. We present the outcomes of this treatment strategy in a UK peritoneal malignancy national referral centre. METHODS: Observational retrospective analysis of data prospectively collected in a dedicated peritoneal malignancy database between March 1998 and January 2016. RESULTS: Of 1586 patients treated for peritoneal malignancy, 76 (4.8%) underwent surgery for peritoneal mesothelioma. Median age was 49 years (range 21-73 years). 34 patients (45%) were female. Of the 76 patients, 39 (51%) had low grade histological subtypes (mostly multicystic mesothelioma), and 37 (49%) had diffuse malignant peritoneal mesothelioma (DMPM; mostly epithelioid mesothelioma). Complete cytoreduction was achieved in 52 patients (68%) and maximal tumour debulking (MTD) was performed in 20 patients (26%); the remaining 4 patients (5%) underwent a laparotomy with biopsy only. HIPEC was administered in 67 patients (88%). Median overall (OS) and disease-free survival (DFS) after CRS was 97.8 (80.2-115.4) and 58.8 (47.4-70.3) months, respectively. After complete cytoreduction, 100% overall survival was observed amongst patients with low-grade disease. Ki-67 proliferation index was significantly associated with survival outcomes after complete cytoreduction for DMPM and was an independent predictor of decreased survival. CONCLUSION: With adequate patient selection (guided by histological classification and Ki-67 proliferation index) and complete cytoreduction with HIPEC, satisfactory outcomes can be achieved in selected patients with peritoneal mesothelioma.

Diagnostic and therapeutic laparoscopy in assessment and management of patients with appendiceal neoplasms.

INTRODUCTION: Radiological imaging often underestimates the extent of low volume peritoneal disease. The benefit of laparoscopy in assessing peritoneal metastases from colorectal and gastric cancer is accepted, but is inconclusive for appendiceal malignancy. We report our experience of diagnostic (DL) and therapeutic laparoscopy (TL) in patients with appendiceal tumours to determine indications and role in assessment and management. METHODS: A retrospective review of a National Peritoneal Malignancy Centre's prospectively maintained database was performed. All patients with appendiceal neoplasms who underwent DL or TL between September 2011 and January 2016 were included. The indications and outcomes of the laparoscopy, complications and interval to laparotomy were evaluated. RESULTS: Six hundred and eighty-five patients underwent surgery for appendiceal neoplasms during the study period, of which 73 (10.6%) underwent laparoscopy (50 DL, 23 TL). The main indications for DL were to clarify imaging and stage patients with high-risk histology. Indications for TL were an abnormal appendix without gross pseudomyxoma peritonei (PMP) or with low volume PMP, and concerns for fertility in the presence of PMP. DL resulted in 16 patients (32%) avoiding laparotomy because of extensive disease or no tumour found. Overall, 28 patients were assessed to have resectable disease and at laparotomy, 25/28 had complete cytoreduction with three patients unresectable. In the TL group, appendicectomy and peritoneal lavage was achieved in all four women with fertility concerns, allowing them to conceive thereafter. There were no complications. CONCLUSIONS: Patients with high-risk appendiceal neoplasm may benefit from DL, and potentially avoid unnecessary laparotomy. TL is useful in patients with low volume PMP and may aid fertility in selected patients.

The histopathological classification, diagnosis and differential diagnosis of mucinous appendiceal neoplasms, appendiceal adenocarcinomas and pseudomyxoma peritonei.

The vermiform appendix is the primary site of several distinctive benign and malignant neoplasms. Some can produce the clinical syndrome of pseudomyxoma peritonei (PMP). A consensus on their terminology was reached by an international panel of pathologists and clinicians working under the auspices of the Peritoneal Surface Oncology Group International (PSOGI), and this review discusses the application of the PSOGI classification to routine reporting. We discuss diagnosis and differential diagnosis together with implications for patient management, covering low-grade appendiceal mucinous neoplasms, high-grade appendiceal mucinous neoplasms, serrated polyps, adenomas and adenocarcinomas. We do not cover goblet cell tumours or neuroendocrine neoplasms in this paper.

Peritoneal Involvement Is More Common Than Nodal Involvement in Patients With High-Grade Appendix Tumors Who Are Undergoing Prophylactic Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Right hemicolectomy is routinely recommended in patients with histologic findings of high-grade appendix tumors after appendicectomy. Undetected peritoneal disease may be encountered at surgery. In high-grade appendix tumors with disease detected radiologically, complete cytoreduction may not be possible and outcomes poor. For these reasons, we adopted a policy of prophylactic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. OBJECTIVE: The purpose of this study was to quantify the rates of peritoneal and nodal metastatic disease in patients with high-grade appendix tumors without obvious metastatic disease and to report the long-term outcomes of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in these patients. DESIGN: Data regarding peritoneal and nodal metastatic disease were extracted from surgical and histologic records. SETTINGS: The study was conducted at a high-volume tertiary referral center for peritoneal malignancy. PATIENTS: Patients referred with histologically high-grade appendix tumors at appendicectomy, without detectable metastatic spread, between January 1994 and September 2016 were included MAIN OUTCOME MEASURES:: A total of 62 patients with high-grade pathology at appendicectomy, without clinical or radiological peritoneal disease, underwent complete cytoreduction with hyperthermic intraperitoneal chemotherapy. RESULTS: Thirty-five (57%) of 62 patients had peritoneal disease (median peritoneal cancer index 5 (range, 1-28)). Eleven (31%) of 35 had microscopic peritoneal disease. Overall, 23 (37%) of 62 had peritoneal disease beyond the confines of a standard right hemicolectomy. Nine (15%) of 62 had nodal involvement. Mean overall and disease-free survival were 110.9 (95% CI, 94.8-127.0 mo) and 102.1 months (95% CI, 84.3-119.9 mo), with 5-year overall and disease-free survival of 83.2% and 76.0%. LIMITATIONS: The retrospective nature limits the interpretation of these results. CONCLUSIONS: Complete cytoreduction was achieved in all of the patients, with excellent long-term survival. The incidence of peritoneal spread (57%) compared with nodal involvement (15%) supports cytoreductive surgery and hyperthermic intraperitoneal chemotherapy as definitive treatment rather than prophylaxis in patients with high-grade appendix tumors, even without radiologically detectable disease. High-grade appendix tumors benefit from early aggressive operative management to deal with potential peritoneal and nodal spread and should be considered for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. See Video Abstract at http://links.lww.com/DCR/A360.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: an emerging treatment option for advanced goblet cell tumors of the appendix.

BACKGROUND: The debate remains whether appendiceal goblet cell cancers behave as classical carcinoid or adenocarcinoma. Treatment options are unclear and reports of outcomes are scarce. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS+HIPEC) is considered optimal treatment for peritoneal involvement of other epithelial appendiceal tumors. METHODS: Prospective cohorts of patients treated for advanced appendiceal tumors from three peritoneal malignancy centres were collected (1994-2011). All patients underwent complete CRS+HIPEC, when possible, or tumor debulking. Demographic and outcome data for patients with goblet cell cancers were compared to patients with low- or high-grade epithelial appendiceal tumors treated during the same time period. RESULTS: Details on 45 goblet cell cancer patients were compared to 708 patients with epithelial appendix lesions. In the goblet cell group, 57.8 % were female, median age was 53 years, median peritoneal cancer index (PCI) was 24, and CRS+HIPEC was achieved in 71.1 %. These details were similar in patients with low- or high-grade epithelial tumors. Lymph nodes were involved in 52 % of goblet cell patients, similar to rates in high-grade cancers, but significantly higher than in low-grade lesions (6.4 %; p < 0.001). At 3 years, overall survival (OS) was 63.4 % for goblet cell patients, intermediate between that for high-grade (40.4-52.2 %) and low-grade (80.6 %) tumors. On multivariate analysis, tumor histology, PCI, and achievement of CRS+HIPEC were independently associated with OS. CONCLUSIONS: This data supports the concept that appendiceal goblet cell cancers behave more as high-grade adenocarcinomas than as low-grade lesions. These patients have reasonable long-term survival when treated using CRS+HIPEC, and this strategy should be considered.

Current concepts in pseudomyxoma peritonei.

Each year, about two per million individuals will be diagnosed with pseudomyxoma peritonei, a disease characterised by the intra-abdominal growth of neoplastic mucin-secreting cells on peritoneal surfaces. The distribution of the disease within the abdomen is not random but depends on physiological principles. Most cases derive from neoplasms of the appendix. In the past, the ovary was considered a common primary site. However, we now know that the ovary is only rarely the source of pseudomyxoma, and that lesions which would previously have been called "borderline mucinous tumours of the ovary" are typically metastatic from the appendix. The grade of the neoplastic cells in pseudomyxoma is an important prognostic factor, but unfortunately there is no consensus on terminology. An international expert group of pathologists and clinicians is currently working on the harmonisation of terminology in this field. Expertise in the management of pseudomyxoma can be achieved by concentrating the treatment of patients in specialised centres or through the development of networks.

Fear of Cancer Recurrence in peritoneal malignancy patients following treatment: a cross-sectional study.

PURPOSE: To assess Fear of Cancer Recurrence (FCR)-its prevalence, trajectory, and relationship to several demographic and clinical characteristics, and quality of life-in a sample of peritoneal malignancy survivors, up to 5 years post-surgery. METHODS: The Fear of Cancer Recurrence Inventory-Short Form (FCRI-SF) and 36-Item Short-Form Health Survey (SF-36) were used to collect cross-sectional data from peritoneal malignancy survivors to assess their Fear of Cancer Recurrence and quality of life respectively as well as other demographic and clinical data. RESULTS: The results show that more than two-thirds of the participants (N = 301) experience severe/clinical FCR. FCR is relatively stable over time. Younger patients who are struggling with anxiety or depression or receiving professional mental health support at the time of the surgery are at a higher risk of FCR. FCR is associated with a worse quality of life. CONCLUSIONS: Peritoneal malignancy survivors are at a high risk of FCR, and it compromises their psychological, mental, and social well-being (quality of life). IMPLICATIONS FOR CANCER SURVIVORS: Raise awareness about the high risk of FCR in this population and the demographic and clinical factors that are associated with it. Encourage peritoneal malignancy services and health professionals to address FCR in this population by normalizing it and providing support for those struggling with it.

Development and Validation of Nomograms to Predict Survival in Patients Undergoing Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei of Appendiceal Origin.

Importance: Pseudomyxoma peritoni, a rare condition characterized by mucinous ascites and peritoneal deposits, mainly originates from a ruptured mucinous appendix tumor and is considered an indolent disease but can progress and become fatal. Optimal treatment to improve cure and survival rates involves complete cytoreductive surgery (CCRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Accurate predictive models are useful in supporting and informing treatment strategies and stratifying patient follow-up. Objective: To evaluate the prognostic significance of clinically important variables and generate validated nomograms to predict overall (OS) and disease-free survival (DFS) following CCRS and hyperthermic intraperitoneal HIPEC for pseudomyxoma peritonei (PMP) of appendiceal origin. Design, Setting, and Participants: This retrospective study used prospectively collected data on patients who had cytoreductive surgery (CRS) and HIPEC in a single institution between 1994 and 2018. The cohort was randomly allocated into development (70%) and validation (30%) sets. Univariate and multivariate analyses were performed with Cox proportional hazards regression. Main Outcomes and Measures: A prediction model was developed with significant prognostic factors identified by multivariate analysis. The model's prognostic performance was evaluated with the concordance index (C index). The nomogram was calibrated by comparing the predicted and observed probabilities. Results: Of 2637 CRS and HIPEC operations, 1102 patients (female, 64.4%; median age [IQR], 57.0 [48.0-66.0] years) (41.8%) had CCRS for PMP of appendiceal origin. Elevated tumor markers, peritoneal carcinomatosis index, gastrectomy, and tumor grade were independent predictive factors for DFS. Gender, age, elevated tumor makers, peritoneal carcinomatosis index, and tumor grade influenced OS. The nomograms were generated with respective prognostic factors. The nomograms showed good performance in predicting survival. Median OS of the cohort was 16.5 years (95% CI, 13.7-19.2) with a 5-year probability of survival of 80.2%. The median DFS was 10.3 years (95% CI, 7.2- 13.3) and the 5-year probability of recurrence-free survival was 60.5%. Conclusions and Relevance: Clinically important independent predictors for survival and recurrence were selected to develop the nomograms for OS and DFS. These 2 nomograms are user friendly and useful tools for patient management with clinical trial design applications.

Pseudomyxoma Peritonei Arising from Urachal Mucinous Neoplasms: a Case Series and Updated Literature Review.

To report a case series of patients with pseudomyxoma peritonei (PMP) from urachal mucinous neoplasm (UMN) treated with CRS and HIPEC at a high-volume referral centre, along with an updated literature review. Retrospective review of cases treated between 2000 and 2021. A literature review using MEDLINE and Google Scholar databases was performed. Clinical presentation of PMP from UMN is heterogeneous, and common symptoms are abdominal distension, weight loss, fatigue and haematuria. At least one tumour marker among CEA, CA 19.9, and CA 125 was elevated in the six cases reported, and 5/6 had a preoperative working diagnosis of urachal mucinous neoplasm suspected on detailed cross-sectional imaging. Complete cytoreduction was achieved in five cases, while one patient underwent maximal tumour debulking. Histological findings mirrored the findings of PMP from appendiceal mucinous neoplasms (AMN). Overall survival ranged between 43 and 141 months after complete cytoreduction. On literature review, 76 cases have been reported to date. Complete cytoreduction is associated with good prognosis for patients with PMP from UMN. A definitive classification system is still not available. Supplementary Information: The online version contains supplementary material available at 10.1007/s13193-022-01694-5.

Correlation between the endoscopic and histologic diagnosis of gastritis.

Our aims were to determine the rate of concordance between endoscopic and pathologic diagnoses of gastritis and to determine if there was any common factor in discordant cases. A retrospective analysis of data from 400 patients was performed. The endoscopic diagnoses were compared with the pathologic diagnoses, and histologic slides from discordant cases were reviewed. Of the 400 patients, there was discordance between endoscopy and histology in 136 (34%; κ statistic, 0.31). These discordant cases comprised 56 with normal endoscopy but abnormal histology and 80 with abnormal endoscopy but normal histology. In 13 patients, there was normal histology, although erosions had been diagnosed endoscopically. No consistent histologic features were found in the discordant cases. These findings show that standard endoscopy is a poor predictor of pathologic changes. Biopsies are required for accurate diagnosis of gastritis.

Fear of cancer recurrence in peritoneal malignancy patients following complete cytoreductive surgery (CCRS) and hyperthermic intraperitoneal chemotherapy (HIPEC): an observational study protocol.

INTRODUCTION: Fear of cancer recurrence (FCR) is correlated with higher depression levels, worse quality of life and increased utilisation of healthcare services. There is no research on FCR in peritoneal malignancy (PM) patients-a rare type of abdominal cancer. This study aims to explore the prevalence, trajectory, demographic and clinical characteristics that are associated with FCR and its relationship with quality of life in PM patients. METHODS AND ANALYSIS: This is a cross-sectional study. Validated measures will be used to collect data on the levels of FCR (Fear of Cancer Recurrence Inventory-Short Form) and quality of life (36-Item Short-Form Health Survey) of PM patients who have had surgery in the last 5 years at the Peritoneal Malignancy Institute in Basingstoke Hospital (minimum N=260). Descriptive statistics, Pearson χ2 tests and correlational tests will be used to analyse the data. ETHICS AND DISSEMINATION: Ethical approval was obtained from the HRA and Health and Care Research Wales (HCRW). The results of this study will be shared with the participants of this study, presented at conferences and PM patients' days in the form of presentations or posters, and published in a scientific journal. DISCUSSION: The results of this exploratory study will be used to inform a multicentre observational study to explore the effect of FCR on PM patients' mental health (depression and anxiety), quality of life and healthcare utilisation which will inform a multicentre randomised controlled trial to assess the effectiveness of using evidenced-based interventions to lower FCR in PM patients.

High-Grade Appendiceal Mucinous Neoplasm: Clinicopathologic Findings in 35 Cases.

CONTEXT.­: High-grade appendiceal mucinous neoplasm (HAMN) is a relatively recently introduced term describing a rare epithelial neoplasm of the appendix that demonstrates pushing-type invasion but high-grade cytologic atypia. It remains understudied. OBJECTIVE.­: To describe clinicopathologic features of HAMNs. DESIGN.­: We identified 35 HAMNs in a multi-institutional retrospective study. Clinical and histologic features were reviewed in all cases, as well as molecular features in 8 cases. RESULTS.­: Patients were 57 years of age on average and most commonly presented with abdominal/pelvic pain. Histologically, 57% of the tumors showed widespread high-grade features. Architectural patterns in high-grade areas included flat, undulating, or villous growth, and occasionally micropapillary, cribriform, or multilayered growth. Thirteen cases had intact serosa, and the remaining 22 perforated the serosa, including 7 with peritoneal acellular mucin beyond appendiceal serosa and 10 with grade 2 pseudomyxoma peritonei. Molecular abnormalities included KRAS mutations in 7 cases and TP53 mutations in 4. No tumor confined to the appendix recurred. Two patients without pseudomyxoma peritonei at initial presentation developed pseudomyxoma on follow-up. Among 11 patients who presented with pseudomyxoma peritonei, 5 died of disease and 3 were alive with disease at last follow-up. CONCLUSIONS.­: HAMNs have a similar presentation to low-grade appendiceal mucinous neoplasm, and similar stage-based prognosis. When they spread to the peritoneum, they typically produce grade 2 pseudomyxoma peritonei, which may be associated with a worse prognosis than classical grade 1 pseudomyxoma peritonei.