Complete cytoreduction for pseudomyxoma peritonei is optimal but maximal tumor debulking may be beneficial in patients in whom complete tumor removal cannot be achieved

Selective Gastrectomy with Knowledge of Gastric Anatomy and Blood Supply are Key to Complete Tumour Removal in Advanced Pseudomyxoma: Single-Centre Experience with 120 Gastrectomies Over 20 Years

BACKGROUND

The role of gastrectomy to achieve complete cytoreduction (CCR) for pseudomyxoma peritonei (PMP) is controversial due to uncertain risk/benefit ratio. The outcomes of patients who gastrectomy over a twenty-year period in a high-volume unit are reported.

METHODS

All patients requiring gastrectomy to achieve CCR for appendiceal PMP between 2000 and 2020 were reviewed. Demographics, disease, operative, complication, and survival data were analysed. The first and second decades were compared.

RESULTS

A total of 2148 patients underwent CRS and HIPEC, of which 78% had CCR. Gastrectomy was performed in 7.1%. Median age was 55 years, and 52% were female. Among gastrectomy patients, 94.2% had ≥1 elevated tumour marker, and 18% had high-grade disease. Median PCI was 30, and 30% required subtotal colectomy. Clavien-Dindo III-IV complications occurred in 32%, and 90-day mortality was 1.75%. Median survival was 104 months, and 10-year OS was 47%. Comparing the two decades, total CRS cases almost tripled, with a greater proportion achieving CCR (82.2% vs. 67.8%) but fewer requiring gastrectomy (5.3% vs. 13.5%). In those who had gastrectomy, disease was more advanced (higher PCI, more high-grade disease, more colectomies) in the later period. However, on multivariable analysis, there was no difference in survival between decades. High-grade histology was the only predictor of survival.

CONCLUSIONS

Gastrectomy can achieve good long-term survival with low mortality and acceptable morbidity and should not deter surgeons from achieving CCR. However, increasing experience shows CCR can be achieved, preserving the stomach in the majority of cases through careful consideration of the anatomy and gastric blood supply.

An observational cohort of patients with colorectal peritoneal metastases or pseudomyxoma peritonei treated with CRS-HIPEC: Development and first results of the Dutch CRS-HIPEC quality registry

INTRODUCTION

To improve care for patients with colorectal peritoneal metastases (CRC-PM) or pseudomyxoma peritonei (PMP), the Dutch CRS-HIPEC quality registry was initiated in 2019. The aims are to describe the development and content of this registry and to give insight into the data collected during the first years.

MATERIALS AND METHODS

The registry is an observational cohort in the Netherlands. All patients with CRC-PM or PMP who intend to undergo cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) from 6 hospitals are included. Clinical data and outcomes (including hospital variation) were analyzed.

RESULTS

In 2019-2022, 889 patients were included in the CRS-HIPEC quality registry: 749 (84 %) with CRC-PM and 140 (16 %) with PMP. Peritoneal metastases were diagnosed synchronously in 51 % of CRC-PM patients and in 94 % of PMP patients. In patients undergoing complete CRS, the median peritoneal cancer index was 8 (IQR 4-13) for CRC-PM and 15 (IQR 6-26) for PMP. Complete cytoreduction was achieved in 639 CRC-PM patients (97 %) and 108 PMP patients (82 %). HIPEC was mainly performed with mitomycin C (CRC-PM: 94 %, PMP: 92 %). Major postoperative complications (Clavien-Dindo grade ≥3) occurred in 148 CRC-PM patients (22 %) and 30 PMP patients (23 %) with 90-day mortality rates of 2 %. In CRC-PM, differences between hospitals were observed regarding proportions of diagnostic laparoscopies/laparotomies, (neo)adjuvant treatment, ostomy formations and re-admissions.

CONCLUSION

The CRS-HIPEC quality registry provides insight into the outcomes of CRS-HIPEC and enables clinical auditing and observational cohort studies aiming to improve treatment outcomes for patients with CRC-PM and PMP.

Hydatid cysts in the mesocolon mimicking peritoneal pseudomyxoma in a post-appendectomy patient: A case report

We aimed to present a case of two mesocolonic hydatid cysts that mimicked the presentation of peritoneal pseudomyxoma. Hydatidosis is a zoonotic parasitic infection caused by the cestode Echinococcus spp., whose larval stage affects various organs. The present case describes a 40-year-old male patient who presented with severe lower abdominal pain and was diagnosed with acute appendicitis. The patient underwent an appendectomy and was later referred to an oncology surgery clinic because of imaging findings suggestive of peritoneal pseudomyxoma or carcinomatosis. A video-assisted laparoscopic procedure revealed two cysts and microscopic findings confirmed hydatid cysts. The patient was from a hydatidosis-endemic region of southern Brazil. This case highlights the diagnostic challenges and the need for a multidisciplinary approach and careful histopathological analysis in patients with complex abdominal conditions. This also demonstrates the importance of disseminating knowledge about this condition and its management.

New insights in the management of pseudomyxoma peritonei

While a rare entity, peritoneal pseudomyxoma treatment evolves. Decision-making criteria improve with imaging development and exploratory laparoscopy. Surgery remains at the core of the therapeutic strategy whatever disease progression. Complete cytoreduction plus hyperthermic intraperitoneal chemotherapy (HIPEC) is standard of care. Iterative cytoreduction or debulking is sometimes justified. Intraperitoneal chemotherapy modalities change with early postoperative HIPEC or pressurized intraperitoneal aerosol chemotherapy. Systemic or local treatment such as new chemo/immuno-therapies or BromAc should improve outcomes. Expertise and multicentric cooperation are more than ever needed.

Visualizing the landscape of appendiceal tumor research after 2010: A bibliometric study

BACKGROUND

Despite the rarity of appendiceal tumors, research in this field has intensified, resulting in a growing number of studies and published papers. Surprisingly, no comprehensive bibliometric analysis has specifically addressed appendiceal tumors.

AIM

To offer a thorough analysis of the current landscape and future trends in appendiceal tumor research.

METHODS

In our bibliometric analysis studies, we explored the Web of Science Core Collection database. The bibliographic details of the chosen publications were automatically converted and analyzed using the bibliometric package in the R environment. Additionally, we employed VoSviewer to create cooperation network maps for countries, institutions, and authors, as well as clustering maps for keywords. Furthermore, CiteSpace, another software tool, was utilized to build dual-map overlays of journals and analyze references with citation bursts.

RESULTS

Our study included 780 English-language articles published after 2010. The number of related publications and citations has increased in the past decade. The United States leads in this area, but there is a need to improve cooperation and communication among countries and institutions. Co-occurrence analysis also revealed close collaboration among different authors. Annals of Surgical Oncology was the most influential journal in this field. Analysis of references with high co-citations and references with citation bursts, consistent with analysis of keywords and hotspots, indicated that current research primarily centers on the classification and management of appendiceal mucinous neoplasms and consequent pseudomyxoma peritonei. Despite the abundance of clinical studies, a greater number of in-depth basic research studies should be conducted.

CONCLUSION

Current research on appendiceal tumors focuses on classification and management of appendiceal mucinous neoplasms and pseudomyxoma peritonei. Enhanced collaboration and basic research are vital for further advancement.

Breaking the Mucin Barrier: A New Affinity Chromatography-Mass Spectrometry Approach to Unveil Potential Cell Markers and Pathways Altered in Pseudomyxoma Peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare peritoneal mucinous carcinomatosis with largely unknown underlying molecular mechanisms. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is the only therapeutic option; however, despite its use, recurrence with a fatal outcome is common. The lack of molecular characterisation of PMP and other mucinous tumours is mainly due to the physicochemical properties of mucin.

RESULTS

This manuscript describes the first protocol capable of breaking the mucin barrier and isolating proteins from mucinous tumours. Briefly, mucinous tumour samples were homogenised and subjected to liquid chromatography using two specific columns to reduce mainly glycoproteins, albumins and immunoglobulin G. The protein fractions were then subjected to mass spectrometry analysis and the proteomic profile obtained was analysed using various bioinformatic tools. Thus, we present here the first proteome analysed in PMP and identified a distinct mucin isoform profile in soft compared to hard mucin tumour tissues as well as key biological processes/pathways altered in mucinous tumours. Importantly, this protocol also allowed us to identify MUC13 as a potential tumour cell marker in PMP.

CONCLUSIONS

In sum, our results demonstrate that this protein isolation protocol from mucin will have a high impact, allowing the oncology research community to more rapidly advance in the knowledge of PMP and other mucinous neoplasms, as well as develop new and effective therapeutic strategies.

Complexity of surgery and treatment burden in patients with peritoneal malignancy is not determined by addition of hyperthermic intraperitoneal chemotherapy

BACKGROUND

This study describes surgical and quality of life outcomes in patients with peritoneal malignancy treated by cytoreductive surgery (CRS) alone compared with a subgroup treated with CRS and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

Peritoneal malignancy patients undergoing surgery between 2017 and 2023 were included. The cohort was divided into patients treated by CRS and HIPEC and those treated by CRS without HIPEC (including CRS only or maximal tumour debulking (MTB)). Main outcomes included surgical outcomes, survival, and quality of life. Groups were compared using non-parametric tests and log-rank test was used to compare survival curves.

RESULTS

403 had CRS and HIPEC, 25 CRS only and 15 MTB. CRS and HIPEC patients had a lower peritoneal carcinomatosis index (12.0 vs. 17.0 vs. 35.0; P < 0.001) and longer surgical operative time (9.3 vs. 8.3 vs. 5.2 h; P < 0.001), when compared to CRS only and MTB, respectively. No other significant difference between groups was observed.

CONCLUSIONS

The optimal management of selected patients with resectable peritoneal malignancy incorporates a combined strategy of CRS and HIPEC. When HIPEC is not utilized, due to significant residual disease or comorbidity precluding safe delivery, CRS alone is associated with good outcomes. Hospital stay and complications are acceptable but not significantly different to the CRS and HIPEC group. CRS alone is a complex intervention requiring comparable resources with good outcomes. In view of our findings 'intention to treat' with CRS and HIPEC should be the basis for resource allocation and funding.

Appendicitis to multivisceral transplantation: a career experience with appendiceal malignancy

John Hunter is regarded as the father of scientific surgery. His principles involved reasoning, observation and experimentation. His most powerful saying was: "Why not try the experiment?" This manuscript charts a career in abdominal surgery ranging from the treatment of appendicitis to the development of the largest appendiceal tumour centre in the world. The journey has led to the first report of a successful multivisceral and abdominal wall transplant for patients with recurrent non-resectable pseudomyxoma peritonei. We all stand on the shoulders of giants and surgery progresses by learning from the past while being prepared to experiment into the future.

Health related quality of life is excellent and sustained at two decades after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in survivors of pseudomyxoma peritonei of appendiceal origin

INTRODUCTION

Optimal management of pseudomyxoma peritonei (PMP) is by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), which can achieve 20-year disease-free, and overall survival. There is limited information on the health-related quality of life (HRQOL) of PMP survivors beyond five years. We report longitudinal HRQOL in patients with PMP of appendiceal origin up to 17-years after their CRS and HIPEC in 2003-2004.

METHODS

Patients had HRQOL assessed with EORTC QLQ-C30 questionnaires pre-operatively, and at 1-, 10- and 17-years post-operatively. Comparisons in global health-related QOL (global-HRQOL) measures were made with (1) an age- and sex-matched normal European population, (2) between patients who underwent complete cytoreduction (CRS CC0/1) versus maximal tumor debulking (MTD), and (3) between those with and without peritoneal recurrence.

RESULTS

Forty-six patients underwent CRS & HIPEC for appendiceal PMP. One patient withdrew from the study. Of the 45 patients, 23 patients were alive at ten and 15 patients at 17-years post-operatively. 21/23 (91%) and 14/15 patients (93%) completed questionnaires respectively. Pre-operatively, patients had significantly lower global-HRQOL compared with the reference population. Over follow-up, patients experienced improvements in their global-HRQOL. By post-operative year-10 and -17, there was no difference between the global-HRQOL of patients and reference population. As expected, patients with CC0/1 and without peritoneal tumor recurrence had better global-HRQOL at ten- and 17-years post-operatively compared with those with MTD or recurrence.

CONCLUSIONS

Optimal CRS and HIPEC is an effective treatment for appendiceal PMP that can achieve long-term survival. HRQOL is excellent and maintained, in those who have CC0/1 without recurrence.

Association of Systemic Chemotherapy Approaches With Outcomes in Appendiceal Peritoneal Metastases

INTRODUCTION

Many patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for appendiceal adenocarcinoma peritoneal metastases (APM) undergo preoperative systemic chemotherapy. The primary aim of this study is to evaluate differences in oncologic outcomes among two popular chemotherapy approaches in patients with APM undergoing CRS-HIPEC.

METHODS

We performed a multicenter retrospective review of patients who underwent CRS-HIPEC for APM due to high or intermediate grade disease between 2013 and 2019. Patients in the total neoadjuvant therapy group (TNT) received 12 cycles of preoperative chemotherapy. Patients in the "sandwich" chemotherapy group (SAND) received six cycles of preoperative chemotherapy with a maximum of six cycles of postoperative chemotherapy. The primary outcomes were overall survival (OS) and recurrence-free survival (RFS) defined as months from date of first treatment or surgery, respectively.

RESULTS

A total of 39 patients were included in this analysis, with 25 (64%) patients in the TNT group and 14 (36%) patients in the SAND group. Patients in the TNT group had a median OS of 62 mo, while median OS in the SAND group was 45 mo (P = 0.01). In addition, patients in the TNT group had significantly longer RFS compared to the SAND group (35 versus 12 mo, P = 0.03). In a multivariable analysis, TNT approach was independently associated with improved OS and RFS.

CONCLUSIONS

In this multicenter retrospective analysis, a TNT approach was associated with improved overall and recurrence-free survival compared to a sandwiched chemotherapy approach in patients undergoing CRS-HIPEC for high or intermediate grade APM.

Pseudomyxoma peritonei induced by a well-differentiated appendicular mucinous adenocarcinoma: An uncommon cause of isolated ascites in a young man patient

Pseudomyxoma peritonei (PMP) remains difficult to diagnose and has a reserved prognosis. Pseudomyxoma peritonei is a rare entity, of appendicular origin in the majority of cases. Its clinical symptomatology is not specific, and the diagnosis is evoked by imaging and surgery and confirmed by histology.

Intraoperative oxygen tension and redox homeostasis in Pseudomyxoma peritonei: A short case series

Introduction

Pseudomyxoma peritonei (PMP) is a rare malignant disease characterized by a massive multifocal accumulation of mucin within the peritoneal cavity. The current treatment option is based on complete cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy. However, the recurrence is frequent with subsequent progression and death. To date, most of the studies published in PMP are related to histological and genomic analyses. Thus, the need for further studies unveiling the underlying PMP molecular mechanisms is urgent. In this regard, hypoxia and oxidative stress have been extensively related to tumoral pathologies, although their contribution to PMP has not been elucidated.

Methods

In this manuscript, we have evaluated, for the first time, the intratumoral real-time oxygen microtension (pO2mt) in the tumor (soft and hard mucin) and surrounding healthy tissue from five PMP patients during surgery. In addition, we measured hypoxia (Hypoxia Inducible Factor-1a; HIF-1α) and oxidative stress (catalase; CAT) markers in soft and hard mucin from the same five PMP patient samples and in five control samples.

Results

The results showed low intratumoral oxygen levels, which were associated with increased HIF-1α protein levels, suggesting the presence of a hypoxic environment in these tumors. We also found a significant reduction in CAT activity levels in soft and hard mucin compared with healthy tissue samples.

Discussion

In conclusion, our study provides the first evidence of low intratumoral oxygen levels in PMP patients associated with hypoxia and oxidative stress markers. However, further investigation is required to understand the potential role of oxidative stress in PMP in order to find new therapeutic strategies.

Diagnostic and Therapeutic Algorithm for Appendiceal Tumors and Pseudomyxoma Peritonei: A Consensus of the Peritoneal Malignancies Oncoteam of the Italian Society of Surgical Oncology (SICO)

Aim: Pseudomyxoma peritonei (PMP) is an uncommon pathology, and its rarity causes a lack of scientific evidence, precluding the design of a prospective trial. A diagnostic and therapeutic algorithm (DTA) is necessary in order to standardize the disease treatment while balancing optimal patient management and the correct use of resources. The Consensus of the Italian Society of Surgical Oncology (SICO) Oncoteam aims at defining a diagnostic and therapeutic pathway for PMP and appendiceal primary tumors applicable in Italian healthcare. Method: The consensus panel included 10 delegated representatives of oncological referral centers for Peritoneal Surface Malignancies (PSM) affiliated to the SICO PSM Oncoteam. A list of statements regarding the DTA of patients with PMP was prepared according to recommendations based on the review of the literature and expert opinion. Results: A consensus was obtained on 33 of the 34 statements linked to the DTA; two flowcharts regarding the management of primary appendiceal cancer and peritoneal disease were approved. Conclusion: Currently, consensus has been reached on pathological classification, preoperative evaluation, cytoreductive surgery technical detail, and systemic treatment; some controversies still exist regarding the exclusion criteria for HIPEC treatment. A shared Italian model of DTA is an essential tool to ensure the appropriateness and equity of treatment for these patients.

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

Transfusion of stored autologous blood in patients with low-grade pseudomyxoma peritonei: A retrospective analysis of its safety and outcome

BACKGROUND

Pseudomyxoma peritonei is a rare disease that presents as a malignant tumor on the peritoneal surface. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is the standard treatment for this disease and frequently requires a red blood cell transfusion. However, due to the limited collection and supply of allogeneic blood, surgical treatment may be delayed due to inadequate preparation of allogeneic blood in the course of clinical treatment. This study aimed to evaluate the safety and efficacy of transfusion of stored autologous blood in patients with low-grade pseudomyxoma peritonei.

METHODS

Pseudomyxoma peritonei patients who received cytoreductive surgery combined with heat-infused peritoneal chemotherapy were divided into two groups: transfusion of allogeneic blood and transfusion of stored autologous blood. A comparison of the differences in multiple factors between the two groups was performed, including tumor recurrence, survival time, hemoglobin and hematocrit levels, coagulation function (prothrombin time, activated partial thromboplastin time, and fibrinogen), total hospital stay duration, and incidence of serious adverse events after surgery.

RESULTS

Propensity scores matching analysis yielded 34 patients with allogeneic blood transfusion and 34 patients with stored autologous blood transfusion. Comparison analysis did not show statistical differences in several factors, including age, tumor grade, tumor recurrence rate after surgery, etc., between the two groups. The cytoreductive degree was considered an independent risk factor for tumor recurrence. The pseudomyxoma peritonei patients in the autologous transfusion group had a higher 5-year survival rate and a longer survival time. Moreover, transfusion of stored autologous blood did not increase the rate of tumor recurrence, or the total hospital stay duration after surgery, the hemoglobin level and coagulation function were well stabilized within 24 h after surgery, and there was a low incidence of serious adverse events.

CONCLUSION

The clinical application of transfusion of stored autologous blood in pseudomyxoma peritonei patients is safe and effective.

Scalloping of the Liver and Spleen on Preoperative CT-Scan of Pseudomyxoma Peritonei Patients: Impact on Prediction of Resectability, Grade, Morbidity and Survival

Simple Summary

Liver and/or spleen scalloping is a common radiologic sign visible on preoperative computed tomography scans of pseudomyxoma peritonei patients. While several studies have reported a predictive value of this scalloping regarding resectability, histologic grade, postoperative morbidity risk and long-term oncologic outcomes, few data are available regarding splenic scalloping. The predictive value of hepatic and splenic scalloping characteristics (measures and density) was assessed. It appeared that scalloping was associated for a more extensive disease, requiring more complex cytoreduction, but it was not associated with resectability, histologic grade, postoperative complications, or survival.

Abstract

Pseudomyxoma peritonei (PMP) is ideally treated by cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), leading to significant morbidity. Beyond the histologic grade, the prognosis lies in the completeness of cytoreduction (CC-score of 0/1 vs. 2/3) and the severe complication rate. The mucinous nature of the peritoneal implants sometimes induces liver and/or spleen scalloping on imaging. The predictive value of scalloping was assessed regarding resectability, grade, survival and severe morbidity. This monocentric, retrospective analysis compared CC-0/1 with CC-2/3 groups regarding liver and spleen scalloping parameters, assessed on pre-operative computed tomography (CT) scan, reviewed for the study. In addition, prognostic factors of severe complications and recurrence-free and overall survivals were explored in the CC-0/1 population. Overall, 129 patients were included (109 CC-0/1, 20 CC-2/3), with 58 (45%) exhibiting scalloping. All patients with splenic scalloping also had a liver one. Scalloping was more frequent (75% vs. 39%), with greater median maximal depth (21 vs. 11 mm) and higher PCI (32 vs. 14) in the CC-2/3 population, but was not predictive of either grade or survival. In CC-0/1 patients, survivals and postoperative complications were not affected by scalloping parameters. Scalloping appeared as a marker of advanced PMP, but was not predictive of grade, severe complications, or long-term outcomes.

Enteral nutrition provides favorable postoperative outcomes for patients with pseudomyxoma peritonei: a retrospective study

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare malignancy, and many uncertainties regarding its treatment and prognosis still remain. The main treatment for PMP is cytoreductive surgery (CRS) combined with heated intraperitoneal chemotherapy (HIPEC), which can lead to intra-abdominal trauma and systemic reactions. Enteral nutrition (EN) is an important and beneficial perioperative option for major complicated abdominal surgery compared with total parenteral nutrition (TPN). However, the role of EN in PMP after surgery is still unknown. The purpose of this study was to analyze the effects of EN on postoperative outcomes in PMP patients.

METHODS

The perioperative clinical data of PMP patients from Xiangya Hospital of Central South University who accepted CRS plus HIPEC from January 2011 to December 2018 were collected and analyzed. The effects of EN on the nutritional status, postoperative complications, and hospital stay time of patients with PMP were studied. We further analyzed the risk factors affecting hospital stay and complications in PMP patients after surgery.

RESULTS

A total of 51 PMP patients accepted CRS and were enrolled in this study, including 25 cases in the EN group and 26 patients in the TPN group. The baseline demographic characteristics and preoperative nutritional status were not significantly different between the two groups. The postoperative absolute lymphocyte count (P<0.001), hemoglobin (P=0.016), and albumin (P<0.001) levels of the EN group were higher than those of the TPN group, but the postoperative hospital stay time (P=0.008) and the complication rate (P=0.03) in the EN group were less than those in the TPN group. Logistic regression analysis showed that age (P=0.031), American Society of Anesthesiologists (ASA) score (P=0.008), and EN (P=0.024) were independent risk factors for postoperative hospital stay in PMP patients. ASA score (P=0.006), number of prior operations (P=0.021), and EN (P=0.035) were independent risk factors for postoperative complications in PMP patients.

CONCLUSIONS

EN support results in better outcomes and is an independent protective factor for the postoperative hospital stay time and complications of PMP patients.

Appendiceal tumors and pseudomyxoma peritonei: French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (RENAPE, RENAPATH, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of appendicular epithelial tumors (AT) and pseudomyxoma peritonei (PMP) published in March 2020, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org).

METHODS

All French medical societies specialized in the management of AT and PMP collaboratively established these recommendations based on literature until December 2019 and the results of a Delphi vote carried out by the Peritoneal Surface Oncology Group International experts, and graded into 4 categories (A, B, C, Expert Agreement) according to their level of evidence.

RESULTS

AT and PMP are rare but represent a wide range of clinico-pathological entities with several pathological classification systems and different biological behaviors. Their treatment modalities may vary accordingly and range from simple surveillance or laparoscopic appendectomy to complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) and / or systemic chemotherapy. The prognosis of these neoplasms may also largely vary according to their pathological grade and spreading at diagnosis or during the follow-up. Given the rarity of certain situations, the therapeutic strategy adapted to each patient, must be discussed in a specialized multidisciplinary meeting after a specialized pathological and radiological pre-therapeutic assessment and a clinical examination by a surgeon specializing in the management of rare peritoneal malignancies.

CONCLUSION

These recommendations are proposed to achieve the most beneficial strategy in a daily practice as the wide range and the rareness of these entities renders their management challenging. These guidelines are permanently being reviewed.

Nomogram to predict overall survival of patients with pseudomyxoma peritonei of appendiceal origin: A retrospective cohort study

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare disease, with the rate of overall survival (OS) influenced by many factors. The present study aimed to define independent predictors and establish a nomogram for individual risk prediction in PMP patients.

METHODS

One hundred forty-seven PMP patients were consecutively included between June 1, 2013, and November 22, 2019. The log-rank test was used to compare the OS rate between groups; subsequently, variables with p < .10 were subjected to multivariate Cox modeling for defining independent prediction indicators. Finally, a nomogram was established based on independent prognosticators and assessed for internal validation.

RESULTS

Multivariate Cox analysis showed that D-dimer level, carbohydrate antigen (CA) 125 level, CA 19-9 level, degree of radical surgery, and histological grade were all independently associated with OS in PMP patients. A nomogram was plotted and underwent internal validation. The discrimination ability of the nomogram revealed a good predictive ability as indicated by the C-index value (0.825), and calibration plots confirmed good consistency between the predicted and observed survival probabilities.

CONCLUSIONS

Five independent prognostic factors for predicting the survival of PMP patients were identified, and the nomogram based on these independent indicators showed a reasonable discrimination ability for individual risk prediction.

Incidentally found mucinous epithelial tumors of the appendix with or without pseudomyxoma peritonei: diagnostic and therapeutic algorithms based on current evidence

Mucinous appendiceal tumors with or without the pseudomyxoma peritonei (PMP) syndrome are rare, but often present as an incidental finding. The confusing histology and lack of large prospective trials result in a considerable diagnostic and therapeutic challenge in these patients. We propose treatment algorithms in patients with incidentally found mucinous epithelial appendiceal tumors, with or without PMP, based on the currently available evidence. The therapeutic approach should take into account the histology and grade of the primary appendix tumor, as well as those of the associated peritoneal disease.

Short-term outcomes in older patients with peritoneal malignancy treated with cytoreductive surgery and HIPEC: Experience with 245 patients from a national centre

BACKGROUND

Cytoreductive Surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is increasingly accepted as the optimal management of selected patients with peritoneal malignancy. There is limited published evidence on outcomes in older patients treated by this complex therapeutic strategy.

METHODS

A retrospective review of a prospective database of all patients who underwent CRS with HIPEC in a single institution over seven years. A comparative analysis of outcomes in patients under 65 undergoing CRS and HIPEC with patients ≥65 years was performed. The key endpoints were morbidity, mortality, reintervention rate and length of stay in the high dependency/intensive care (HDU/ICU) units.

RESULTS

Overall, 245 patients underwent CRS and HIPEC during the study period, with 76/245 (31%) ≥65 years at the time of intervention. Tumour burden measured by the peritoneal carcinomatosis index (PCI) score was a median of 11 for both groups. Median length of hospital stay in the ≥65-year-old group was 14.5 days versus 13 days in the <65-year-old group (∗p = 0.01). Patients aged ≥65-years spent a median of one more day in the critical care unit ∗(p = 0.001). Significant morbidity (Clavien-Dindo ≥ Grade IIIa) was higher in the ≥65-year than the <65-year group (18.4% versus 11.2%). There were no perioperative deaths in the ≥65-year group.

CONCLUSION

This study demonstrates higher perioperative major morbidity in ≥65-year group, but with low mortality in patients undergoing CRS/HIPEC for disseminated intraperitoneal malignancy. This increased morbidity does not translate into higher rates of re-interventions and highlights the importance of optimal patient selection.

Consensuses and controversies on pseudomyxoma peritonei: a review of the published consensus statements and guidelines

Background

Pseudomyxoma peritonei (PMP) is a clinical malignant syndrome mainly originating from the appendix, with an incidence of 2–4 per million people. As a rare disease, an early and accurate diagnosis of PMP is difficult. It was not until the 1980s that the systematic study of this disease was started.

Main body

As a result of clinical and basic research progress over the last 4 decades, a comprehensive strategy based on cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) has been established and proved to be an effective treatment for PMP. Currently, CRS + HIPEC was recommended as the standard treatment for PMP worldwide. There are several consensuses on PMP management, playing an important role in the standardization of CRS + HIPEC. However, controversies exist among consensuses published worldwide. A systematic evaluation of PMP consensuses helps not only to standardize PMP treatment but also to identify existing controversies and point to possible solutions in the future. The controversy underlying the consensus and vice versa promotes the continuous refinement and updating of consensuses and continue to improve PMP management through a gradual and continuous process. In this traditional narrative review, we systemically evaluated the consensuses published by major national and international academic organizations, aiming to get a timely update on the treatment strategies of CRS + HIPEC on PMP.

Conclusion

Currently, consensuses have been reached on the following aspects: pathological classification, terminology, preoperative evaluation, eligibility for surgical treatment, maximal tumor debulking, CRS technical details, and severe adverse event classification system. However, controversies still exist regarding the HIPEC regimen, systemic chemotherapy, and early postoperative intraperitoneal chemotherapy.

The Prognostic Impact of Pathology on Patients With Pseudomyxoma Peritonei Undergoing Debulking Surgery: A Systematic Review and Meta-Analysis of Retrospective Studies

Background: Pseudomyxoma peritonei (PMP) is a rare clinical condition with fatal outcomes, which is characterized by the progressive accumulation of mucinous ascites and peritoneal implants. Some studies have reported the effect of PMP biology on patient outcome. The objective of this study was to analyze published articles focusing on the impact of pathology on the prognosis of PMP patients undergoing debulking.

Methods: Data from all studies regarding the prognosis of patients, with different pathologies, who underwent debulking surgery were analyzed. We searched PubMed, the Wiley Online Library, Ovid, and the Cochrane Library (through January 2020). Studies were confined to those articles written in English. Five studies were identified, and the differences in 5-year survival rates were analyzed according to the Kaplan–Meier survival curves. The hazard ratios (HRs) of the 5-year survival rates were calculated.

Results: The mean and median 5-year survival rates of all patients were 39 and 40%, respectively. The median overall survival was 49.3 months. The mean 5-year survival rates of low-grade PMP was 45.2%. The five studies had sufficient data to calculate HRs from the 5-year survival rates data, and three had HRs lower than 1. The total HRs was 0.54, with a 95% CI between 0.33 and 0.89 (P = 0.01).

Conclusions: Among PMP patients receiving debulking surgery who are not able to undergo complete cytoreductive surgery, low-grade biological PMP had a better prognosis than high-grade PMP.

Mode of Presentation in 1070 Patients With Perforated Epithelial Appendiceal Tumors, Predominantly with Pseudomyxoma Peritonei

BACKGROUND

Perforated epithelial appendiceal tumors are uncommon and can give rise to pseudomyxoma peritonei. Pseudomyxoma peritonei is rare, almost always of appendiceal origin, and presents in various ways relevant to abdominal surgeons.

OBJECTIVE

The aim of this study was to report the mode of presentation of pseudomyxoma peritonei of appendiceal origin in patients treated in a high-volume UK peritoneal malignancy center.

DESIGN

A retrospective observational study was conducted.

SETTINGS

This was a single-center study.

PATIENTS

Retrospective analysis of a prospective database of consecutive patients undergoing surgery between March 1994 and December 2016 was performed.

MAIN OUTCOME MEASURES

Mode of presentation was classified into 7 categories: "histological diagnosis at abdominal surgery for presumed appendicitis," "probable pseudomyxoma peritonei" based on abnormality on cross-sectional imaging (± image-guided biopsy)," "abnormal imaging (other cause suspected) and operative finding of pseudomyxoma peritonei," "diagnostic laparoscopy," "ovarian mass," "new-onset hernia," and "miscellaneous."

RESULTS

Overall, 1070 patients underwent surgery (female 61%, male 39%); median age was 57. The mode of presentation was abnormality on cross-sectional imaging in 324 of 1070 patients (30.3%), histological diagnosis at emergency surgery for presumed appendicitis in 203 of 1070 patients (19%), and abnormal imaging with eventual pseudomyxoma peritonei diagnosis in 180 of 1070 patients (16.8%); 124 of 651 women (19.2%) presented with an ovarian mass. New-onset hernia was the presenting feature in 9.9%; 83 of 1070 patients (7.7%) were diagnosed at diagnostic laparoscopy, and 32 of 1070 patients (3%) were described as "miscellaneous." Overall, 775 of 1070 patients (72.4%) had complete cytoreductive surgery with 10-year survival of 63.5%.

LIMITATIONS

Results are limited by the retrospective nature of the study, radiological improvements over the study period, and the number of patients who had overlapping features at presentation.

CONCLUSION

Perforated appendiceal tumors present in various ways but predominantly at cross-sectional imaging or coincidentally at laparoscopy or laparotomy. All abdominal surgeons will occasionally encounter cases, often unexpectedly, and recognition and referral to a specialized unit results in excellent outcomes in most cases. See Video Abstract at http://links.lww.com/DCR/B256. MODO DE PRESENTACIÓN EN 1070 PACIENTES CON TUMORES EPITELIALES APENDICULARES PERFORADOS, PREDOMINANTEMENTE CON PSEUDOMIXOMA PERITONEAL: Los tumores epiteliales apendiculares perforados son poco frecuentes y pueden dar lugar a Pseudomyxoma peritonei. El pseudomixoma peritoneal es raro, casi siempre de origen apendicular, y se presenta de diversas formas relevantes para los cirujanos abdominales.El objetivo fue informar el modo de presentación del Pseudomixoma peritoneal de origen apendicular en pacientes tratados en un centro de malignidad peritoneal de alto volumen en el Reino Unido.Se realizó un estudio observacional retrospectivo.Este fue un estudio de centro único.Análisis retrospectivo de una base de datos prospectiva de pacientes consecutivos sometidos a cirugía entre marzo de 1994 y diciembre de 2016.El modo de presentación se clasificó en 7 categorías: "diagnóstico histológico en la cirugía abdominal por presunta apendicitis", "probable Pseudomixoma peritoneal" basado en la anormalidad en la imagen de corte transversal (biopsia guiada por imagen +/-), "imagen anormal (se sospecha otra causa) y hallazgo quirúrgico de Pseudomixoma peritoneal", "laparoscopia diagnostica", "masa ovarica", "hernia de reciente aparicion" y "varios".En total, 1070 pacientes fueron operados (mujeres 61%, hombres 39%); edad media 57. El modo de presentación fue anormalidad en la imágen transversal en 324/1070 (30.3%), el diagnóstico histológico en cirugía de emergencia por presunta apendicitis en 203/1070 (19%), la imágen anormal con eventual diagnóstico de Pseudomixoma peritoneal en 180 / 1070 (16.8%), 124/651 (19.2%) las mujeres presentaron una masa ovárica. La hernia de reciente aparición fue la característica de presentación en 9.9%, 83/1070 (7.7%) fueron diagnosticados por laparoscopia diagnóstica y 32/1070 (3%) "misceláneos". En general, 775/1070 (72,4%) se sometió a cirugía citorreductora completa con una supervivencia a 10 años del 63,5%.Una deficiencia es que los resultados están limitados por la naturaleza retrospectiva del estudio, las mejoras radiológicas a lo largo del período de estudio, y varios pacientes tenían características superpuestas en la presentación.Los tumores apendiculares perforados se presentan de varias maneras, pero predominantemente en imágenes transversales o casualmente en laparoscopia o laparotomía. Todos los cirujanos abdominales encontrarán ocasionalmente con casos, a menudo inesperados, y el reconocimiento y la derivación a una unidad especializada da lugar a excelentes resultados en la mayoría de los casos. Consulte Video Resumen en http://links.lww.com/DCR/B256.).

Appendiceal tumours and pseudomyxoma peritonei: Literature review with PSOGI/EURACAN clinical practice guidelines for diagnosis and treatment

Pseudomyxoma Peritonei (PMP) is a rare peritoneal malignancy, most commonly originating from a perforated epithelial tumour of the appendix. Given its rarity, randomized controlled trials on treatment strategies are lacking, nor likely to be performed in the foreseeable future. However, many questions regarding the management of appendiceal tumours, especially when accompanied by PMP, remain unanswered. This consensus statement was initiated by members of the Peritoneal Surface Oncology Group International (PSOGI) Executive Committee as part of a global advisory role in the management of uncommon peritoneal malignancies. The manuscript concerns an overview and analysis of the literature on mucinous appendiceal tumours with, or without, PMP. Recommendations are provided based on three Delphi voting rounds with GRADE-based questions amongst a panel of 80 worldwide PMP experts.

Society of Onco-Anaesthesia and Perioperative Care consensus guidelines for perioperative management of patients for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC)

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for primary peritoneal malignancies or peritoneal spread of malignant neoplasm is being done at many centres worldwide. Perioperative management is challenging with varied haemodynamic and temperature instabilities, and the literature is scarce in many aspects of its perioperative management. There is a need to have coalition of the existing evidence and experts' consensus opinion for better perioperative management. The purpose of this consensus practice guideline is to provide consensus for best practice pattern based on the best available evidence by the expert committee of the Society of Onco-Anaesthesia and Perioperative Care comprising perioperative physicians for better perioperative management of patients of CRS-HIPEC.

Acellular mucin in pseudomyxoma peritonei of appendiceal origin: what is adequate sampling for histopathology?

INTRODUCTION

Acellular intra-abdominal mucin is associated with a favourable prognosis in pseudomyxoma peritonei. There are no current guidelines on how many blocks are needed to classify the mucin as acellular with confidence.

METHODS

Specimens from cytoreductive surgery for mucinous appendiceal neoplasia, in which acellular mucin was found on initial histopathological examination, were prospectively identified. Additional tissue blocks were then taken to include either all residual visible intra-abdominal mucin or a maximum of 30 blocks. We also sent a questionnaire to pathologists in other centres.

RESULTS

Twelve patients were identified. In two cases, neoplastic epithelial cells were found on taking additional blocks. The questionnaire results suggested considerable variation in block-taking practice.

CONCLUSION

Taking additional tissue identified neoplastic cells in 2 of 12 cases. We recommend that sampling additional material should be considered when only acellular mucin is found on initial histology. Further work to determine the optimum sampling protocol is indicated.

Diagnostic concordance in cases of appendiceal mucinous neoplasia referred to a tertiary referral centre

Accurate diagnosis of appendiceal tumours and any associated peritoneal disease is clinically important but can be difficult. We retrieved the records of patients referred to the Peritoneal Malignancy Institute, Basingstoke, in the years 2016, 2017 and 2018 with a diagnosis of mucinous appendiceal neoplasia and identified 323 patients in which slides were reviewed as part of the referral pathway. Comparing the local report from the referring centre with the central review report, in 57 (18%) we identified a discrepancy. In 39 (12%) the discrepancy was in overall diagnosis, including 22 (7%) in which the local diagnosis was low-grade appendiceal mucinous neoplasm whereas the review diagnosis was reactive mucosal changes, usually due to ruptured diverticulum, with no evidence of neoplasia. Our findings support the practice of central review of histopathology slides by experienced pathologists at tertiary referral centres. They also suggest that improvements in diagnostic criteria are needed.

Pseudomyxoma peritonei induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer: a case report and literature review

Background

Pseudomyxoma peritonei (PMP) is a disease involving the peritoneum characterized by the production of large quantities of mucinous ascites. PMP has a low incidence, is difficult to diagnose, and has a guarded prognosis. PMP induced by low-grade appendiceal mucinous neoplasm is extremely rare, and PMP accompanied by rectal cancer is even rarer.

Case presentation

We present a unique case of a 70-year-old male with PMP induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer. The patient’s clinical, surgical, and histologic data were reviewed. The patient had persistent distended abdominal pain without radiating lower back pain, abdominal distension for 1 month, and no exhaustion or defecation for 4 days. A transabdominal ultrasound-guided biopsy was performed on the first day. The patient received an emergency exploratory laparotomy because of increased abdominal pressure. We performed cytoreductive surgery, enterolysis, intestinal decompression, special tumour treatment and radical resection of rectal carcinoma. The postoperative course was uneventful. The postoperative histological diagnoses were PMP, low-grade appendiceal mucinous neoplasm and rectal medium differentiated adenocarcinoma. At the 1-year follow-up visit, no tumour recurrence was observed by computed tomography (CT). We also performed a literature review.

Conclusions

We should be aware that PMP can rarely be accompanied by rectal cancer, which represents an easily missed diagnosis and increases the difficulty of diagnosis and treatment. Additionally, there are some typical characteristics of PMP with respect to diagnosis and treatment.

Survival after complete cytoreductive surgery and HIPEC for extensive pseudomyxoma peritonei

INTRODUCTION

The optimal treatment for pseudomyxoma peritonei (PMP) combines complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Yet, achieving CRS is challenging in the case of extensive involvement of the peritoneal cavity and the survival benefit in this setting remains uncertain. The present study evaluated the surgical outcomes according to the peritoneal extent.

METHODS

Between 1992 and 2014, 245 patients underwent CRS and HIPEC for PMP in our institution. Their characteristics were reviewed using a prospective database. Extensive PMP was defined as a peritoneal cancer index (PCI) ≥ 28. Sixty-one patients with extensive PMP were compared to 184 with non-extensive PMP.

RESULTS

Severe complications were more frequent in the extensive group (46% vs. 23%, p < 0.001) but the post-operative mortality was not significantly different (8% vs. 3%, p = 0.1). The 5-year disease-free survival reached 45% in the extensive and 78% in the non-extensive group (p < 0.0001). The 5-year overall survival was 70% and 90% in the extensive and non-extensive group respectively (p < 0.021).

CONCLUSION

CRS with HIPEC offers prolonged survival even in the case of extensive PMP. Because of the high rate of surgical morbidity in the extensive group, patients should be carefully selected.

Biological mesh is a safe and effective method of abdominal wall reconstruction in cytoreductive surgery for peritoneal malignancy

Background

Patients with peritoneal malignancy often have multiple laparotomies before referral for cytoreductive surgery (CRS). Some have substantial abdominal wall herniation and tumour infiltration of abdominal incisions. CRS involves complete macroscopic tumour removal and hyperthermic intraperitoneal chemotherapy (HIPEC). Abdominal wall reconstruction is problematic in these patients. The aim of this study was to establish immediate and long-term outcomes of abdominal wall reconstruction with biological mesh in a single centre.

Methods

A dedicated peritoneal malignancy database was searched for all patients who had biological mesh abdominal wall reconstruction between 2004 and 2015. Short- and long-term outcomes were reviewed. All patients had annual abdominal CT as routine peritoneal malignancy follow-up.

Results

Some 33 patients (22 women) with a mean age of 53·4 (range 19-82) years underwent abdominal wall reconstruction with biological mesh. The majority (23) had CRS for pseudomyxoma (19 low grade), six for colorectal peritoneal metastasis and four for appendiceal adenocarcinoma; 18 had undergone CRS and HIPEC previously. Twenty-five of the 33 patients had abdominal wall tumour involvement and eight had concurrent hernias. The mean duration of surgery was 486 (range 120-795) min and the mean mesh size used was 345 (50-654) cm². Ten patients developed wound infections and four had a seroma. Two developed early enterocutaneous fistulas. Mean follow-up was 48 months. Five patients developed an incisional hernia. Four died from progressive malignancy. A further 15 patients had disease recurrence, but only one had isolated abdominal wall recurrence.

Conclusion

Biological mesh was safe and effective for abdominal wall reconstruction in peritoneal malignancy. Postoperative wound infections were frequent but nevertheless incisional hernia rates were low with no instances of mesh-related bowel erosion or fistulation.

Do patients undergoing cytoreductive surgery and HIPEC for peritoneal malignancy need parenteral nutrition?

BACKGROUND

To analyse the duration of parenteral nutrition (PN) in patients treated for peritoneal malignancy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) over a 2 year period at a single UK National referral centre.

METHODS

A retrospective analysis of prospective data for all patients (n=321) who underwent CRS and HIPEC for peritoneal malignancy at the Peritoneal Malignancy Institute Basingstoke between April 1, 2013 and March 31, 2015.Duration of PN was compared between primary tumour site (appendix, colorectal, mesothelioma and other); completeness of CRS (complete CRS vs. major tumour debulking) and pre-operative nutritional assessment measures (including Mid Upper Arm Circumference).

RESULTS

The median duration of PN was 9 days (range 2-87 days). A total of 13 % of patients had PN for less than 7 days and 6 % for 5 days or less. There was no significant difference in duration of PN between the different tumour sites. Two factors that may increase the duration of PN include having major tumour debulking (MTD) and a baseline MUAC<23.5 cm.

CONCLUSIONS

Most patients who underwent CRS and HIPEC for peritoneal malignancy required PN for more than 7 days with poor pre-operative nutritional status and inability to achieve complete cytoreduction predictors of prolonged PN requirements.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei in a liver-transplanted patient: a case report

BACKGROUND

Diagnostic work-ups in transplanted immunosuppressed patients are a challenge as non-specific findings may be interpreted as transplant-related complications. If the disease in question is rare and slowly developing like pseudomyxoma peritonei (PMP), it is even more difficult. Cytoreductive surgery (CRS) and subsequent hyperthermic intraperitoneal chemotherapy (HIPEC) is the recommended treatment for PMP even with extensive peritoneal spread. CRS-HIPEC for PMP after liver transplantation (LTX) has not been described before.

CASE PRESENTATION

A 48-year-old female patient with end-stage primary sclerosing cholangitis (PSC) underwent orthotopic LTX and subsequent pancreaticoduodenectomy after the finding of cholangiocarcinoma in situ in the native common bile duct. Ten years after the transplantation, she developed symptoms and signs suspected to represent graft-related complications. An extensive work-up revealed PMP. Upon reassessment, a cystic mass near the coecum could be seen on computed tomography scan 1 year after transplantation. The multidisiplinary team was hesitant to accept the patient for CRS-HIPEC because of extensive PMP and possible risk to the graft. However, she was eventually accepted and underwent the procedure. The Peritoneal Cancer Index (PCI) was 28 of 39, and surgical debulking was performed followed by HIPEC. The transplant control 2 months after surgery showed no harm to the graft.

CONCLUSIONS

Previous LTX should not exclude the possibility for CRS-HIPEC in PMP, even with extensive burden of disease.

Patient Selection for Cytoreductive Surgery

The peritoneal malignancies span the biologic spectrum of aggressiveness from the indolent growth pattern and superficial nature of well-differentiated mucinous appendiceal adenocarcinoma to the rapidly growing and invasive nature of poorly differentiated signet ring cell adenocarcinomas of the appendix, colon, and stomach. An understanding of the biology, distribution, and volume of disease is critical to appropriately selecting patients for cytoreduction and HIPEC with the goal of long-term survival. Herein the authors discuss appropriate the evaluation and selection of patients for with peritoneal surface malignancies for cytoreduction and HIPEC.

Long-Term Outcomes after Surgery for Appendiceal Mucinous Tumours

BACKGROUND

Appendiceal mucinous tumour (AMT) is a very uncommon disease. We aimed to evaluate preoperative and postoperative characteristics as well as long-term outcomes of patients with appendiceal mucinous adenomas and peritoneal pseudomyxoma (PMP).

METHODS

A consecutive cohort of patients diagnosed with AMT were included in the study. Tumour recurrence and the development of PMP was diagnosed based on the patients' complaints, physical examination, imaging studies, and biopsy results. The calculation of survival rates was performed using the Kaplan-Meier method.

RESULTS

Between January 2003 and February 2013, 25 patients had AMT. 15 patients underwent appendectomy only (60%), 5 patients (20%) right hemicolectomy, 4 patients (16%) cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC), and 1 patient (4%) appendectomy with caecal resection. Another 2 patients underwent CRS and HIPEC 4 days and 3 years, respectively, following initial appendectomy. In the histopathologic examination, adenoma was diagnosed in 12 patients (48%); among these, low-grade PMP was found in 1 patient (4%). Low-grade appendiceal mucinous adenocarcinoma (AMCa) was diagnosed in 11 patients (44%); among these, low-grade PMP was found in seven cases (28%) and high-grade AMCa was diagnosed in 2 patients (8%). 2 of 8 PMP patients did not undergo CRS ± HIPEC because of comorbidities. The 5-year overall survival was 100% for the adenomas and 62% for PMP patients.

CONCLUSION

AMT is a very rare entity with a considerably good outcome even in disseminated disease. CRS and HIPEC is a gold standard treatment for PMP with excellent prognosis. However, our results could still be improved in the future.

Pseudomyxoma peritonei: natural history and treatment

Pseudomyxoma peritonei (PMP) is an uncommon disease characterised by mucinous ascites, classically originating from a ruptured low grade mucinous neoplasm of the appendix. The natural history of PMP revolves around the "redistribution phenomenon", whereby mucinous tumour cells accumulate at specific sites with relative sparing of the motile small bowel and to a lesser extent other parts of the gastrointestinal tract. Peritoneal tumour accumulates due to gravity and at the sites of peritoneal fluid absorption, namely, the greater and lesser omentum and the under-surface of the diaphragm, particularly on the right. The optimal treatment is complete macroscopic tumour excision termed cytoreductive surgery (CRS) combined with Hyperthermic Intra-Peritoneal Chemotherapy (HIPEC). Total operating time for complete CRS and HIPEC for extensive PMP is around 10 h and generally involves bilateral parietal and diaphragmatic peritonectomies, right hemicolectomy, radical greater omentectomy with splenectomy, cholecystectomy and liver capsulectomy, a pelvic peritonectomy with, or without, rectosigmoid resection and bilateral salpingo-oophorectomy with hysterectomy in females. A unique feature of low grade PMP, which differs from other peritoneal malignancies, includes slow disease progression, which may be asymptomatic until advanced stages. Additionally, very extensive disease with a high "PCI" (Peritoneal Carcinomatosis Index) may still be amenable to complete excision and cure. In cases where complete tumour removal is not feasible, maximum tumour debulking can still result in long-term survival in PMP. PMP is challenging, complex but nevertheless the most rewarding peritoneal malignancy amenable to cure by CRS and HIPEC.

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.

Prediction of Resectability in Pseudomyxoma Peritonei with a New CT Score

BACKGROUND

Curative treatment of pseudomyxoma peritonei (PMP) is complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC).

OBJECTIVE

The aim of this study was to build and evaluate a preoperative imaging score to predict resectability.

PATIENTS AND METHODS

Between 2007 and 2014, all PMP patients in two tertiary reference centers who underwent laparotomy with intent to undergo CRS and HIPEC were included in this study retrospectively. Thickness of tumor burden was measured on preoperative multidetector-row computed tomography (MDCT) by two radiologists blinded to surgical results in five predetermined areas. Patients were divided into two cohorts with the same resectability rate (building and validation). The performances of the scores were assessed using receiver operating characteristic (ROC) curve analyses.

RESULTS

Overall, 126 patients were included, with compete CRS being achieved in 91/126 patients (72.2%). Two cohorts of 63 patients matched by age, sex, burden of disease, resectability rate, and pathological grade were constituted. The MDCT score was the sum of the five measures, and was higher in unresectable disease [median 46.2 mm (range 27.9-74.6) vs. 0.0 mm (range 0.0-14.0), p < 0.001]. Area under the ROC curve was 0.863 (range 0.727-0.968) and 0.801 (range 0.676-0.914) in the building and validation cohorts, respectively. A threshold of 28 mm yielded a sensitivity, specificity, positive predictive and negative predictive value of 94, 81, 81 and 94% in the building cohort, and 80, 68, 59 and 85% in the validation cohort, respectively. Using our score, overall and disease-free survival were increased in the group classified as resectable.

CONCLUSION

A simple preoperative MDCT score measuring tumor burden in the perihepatic region is able to predict resectability and survival of PMP patients.

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.

Clinical presentation, diagnosis, classification and management of peritoneal mesothelioma: a review

Peritoneal mesothelioma (PM) is an uncommon but a serious, and often, fatal primary peritoneal tumour, with increasing incidence worldwide. Conventional systemic chemotherapy, generally based on experience with pleural mesothelioma, usually has disappointing results considering PM as a terminal condition. Patients usually present with non-specific symptoms of abdominal distension and pain making the diagnosis challenging. As PM is confined to the abdomen for all, or much, of its clinical course, a multimodality treatment combining cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has emerged as a new standard of care, and has been reported to achieve promising survival outcomes and local disease control in selected patients with PM. This review updates the presentation, diagnosis, classification and treatment strategies for PM.

Appendiceal Mucinous Neoplasms: Diagnosis and Management

OBJECTIVE

Appendiceal mucinous neoplasms (AMNs) are a rare and heterogeneous disease for which clinical management is challenging. We aim to review the literature regarding modalities of treatment to guide the management of AMNs.

METHODS AND REVIEW CRITERIA

We conducted a PubMed search in February 2016 for English-language publications, using the terms "appendiceal," "appendix," "carcinoma," "cancer," "mucinous," "treatment," "genes," "target," "genomic," and terms listed in the articles' subheadings. Published reports and abstracts from the American Society of Clinical Oncology meetings were also searched.

RESULTS

In this review, we summarize current data and controversies in AMN classification, clinical presentation, molecular alterations, treatment outcomes with regard to cytoreductive surgery, hyperthermic intraperitoneal chemotherapy (HIPEC), and the role of systemic chemotherapy.

CONCLUSION

Appendiceal mucinous neoplasms are a heterogeneous group of tumors with a rising incidence. Treatment is based on stage and histology. Low-grade tumors are treated surgically with resection of the primary site in early stage disease, or peritoneal debulking and HIPEC in patients with advanced stage disease. Treatment of high-grade tumors requires further prospective trials, and options include debulking surgery and HIPEC with or without preoperative chemotherapy. Trials evaluating novel therapies based on the molecular profiling of AMN tumors are needed to evaluate therapeutic options in patients who are not surgical candidates.

IMPLICATIONS FOR PRACTICE

This review provides a reference to guide gastroenterologists, pathologists, surgeons, and oncologists in the management of appendiceal mucinous neoplasms (AMNs), a rare and heterogeneous disease with no consensus on histologic classification or guidelines for treatment algorithms. This review summarizes all AMN classifications and proposes a treatment algorithm based on stage and histology of disease.

"PAUSE": a method for communicating radiological extent of peritoneal malignancy

Radiology reports of diffuse peritoneal disease should address key findings pertinent to the management of these patients. The reporting of radiology findings in patients with peritoneal malignancy is currently variable and poorly standardised. Using the acronym "PAUSE" we emphasise the key imaging features that a radiology report should include in a patient with peritoneal malignancy, focussing on the key elements determining feasibility and likely prognosis of surgery and potential benefits from cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The term "PAUSE" incorporates the following: P, primary tumour and peritoneal carcinomatosis index (PCI) as estimated by imaging; A, ascites and abdominal wall involvement; U, unfavourable sites of involvement; S, small bowel and mesenteric disease; E, extra peritoneal metastases. Thus, "PAUSE" has the potential to standardise radiology reporting in this field.

Risk of Ovarian Involvement in Advanced Colorectal or Appendiceal Tumors Involving the Peritoneum

BACKGROUND

Ovarian metastases of GI tumors grow rapidly and are relatively resistant to systemic chemotherapy. They may be unilateral or bilateral and macroscopic or occult. The risk of macroscopic ovarian involvement or occult involvement of macroscopically normal ovaries is unquantified.

OBJECTIVE

This study aims to quantify the risks of ovarian involvement in patients with peritoneal malignancy undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

DESIGN

This was a retrospective analysis of a dedicated prospective malignancy database.

SETTINGS

This study was conducted at a high-volume tertiary referral center for peritoneal malignancy.

PATIENTS

Female patients with at least 1 remaining ovary, undergoing complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for appendiceal tumors or colorectal peritoneal metastases between January 2010 and March 2015 were included.

OUTCOME MEASURES

Data regarding ovarian involvement was extracted from surgical and histological records.

RESULTS

Two hundred fifty-eight female patients with at least 1 ovary underwent complete cytoreduction and hyperthermic intraperitoneal chemotherapy during the study period. In total, 141 of 258 (54.7%) patients had ovarian tumor involvement, and 80% with at least 1 macroscopically abnormal ovary had bilateral involvement. Of 40 patients with 1 macroscopic ovarian metastasis, microscopic involvement of the contralateral ovary was found in 18 of 40 (45.0%). Of 141 patients in whom both ovaries were macroscopically normal, 24 of 141 (17.0%) patients had microscopic ovarian involvement.

LIMITATIONS

The retrospective nature limits the interpretation of these results.

CONCLUSIONS

Occult malignancy was present in 17% when both ovaries looked macroscopically normal and in 45% of contralateral normal-looking ovaries if the other ovary was macroscopically involved. These results help to inform preoperative consent and intraoperative decision making in patients with advanced appendiceal and colorectal malignancy, and are of benefit in managing advanced lower GI tract malignancy.

Early identification of DPAM in at-risk low-grade appendiceal mucinous neoplasm patients: a new approach to surveillance for peritoneal metastasis

Background

Disseminated peritoneal adenomucinosis (DPAM) patients often have a history of appendectomy with identification of an incidental mucinous neoplasm (low-grade appendiceal mucinous neoplasm (LAMN)). The rate of developing DPAM is not well established.

Methods

Twenty-two patients with incidental LAMN were identified and monitored with cancer markers and CT every 4–6 months. Laparoscopy with peritoneal washing was performed in patients either in the event of radiographic disease or after 12 months in absence of radiographic disease. The rate of detecting peritoneal metastasis was determined for CT scan and laparoscopy.

Results

Peritoneal metastasis was detected in 5 (23 %) patients. Occult disease was detected in four patients at laparoscopy without a detectable disease on CT scan. One patient developed radiographic progression at 6 months confirmed with laparoscopy. Four patients were treated with cytoreductive surgery (CRS)/HIPEC and one with CRS only. The 17 patients with negative laparoscopy remain disease free with a median follow-up of 50 months.

Conclusions

The rate of peritoneal metastasis in incidental LAMN patients was 23 %. Laparoscopy was the primary screening tool identifying occult metastasis. The median PCI of 7 was low, and all the patients underwent R0/R1 resections. This study revealed 1 in every 4.4 patients with LAMN may develop PMP. Longer follow-up and further patient surveillance is warranted.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in 1000 patients with perforated appendiceal epithelial tumours

PURPOSE

To report early and long term outcomes following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in 1000 patients with perforated appendiceal epithelial tumours, predominantly with pseudomyxoma peritonei (PMP).

METHODS

Retrospective analysis of a prospective database of 1000 consecutive patients undergoing CRS and HIPEC for perforated appendiceal tumours between 1994 and 2014 in a UK National Peritoneal Malignancy unit.

RESULTS

Overall 1000/1444 (69.2%) patients treated for peritoneal malignancy had appendiceal primary tumours. Of these 738/1000 (73.8%) underwent complete cytoreductive surgery (CCRS), 242 (24.2%) had maximal tumour debulking (MTD) and 20 (2%) had laparotomy and biopsies only. Treatment related 30-day mortality was 0.8% in CCRS and 1.7% in MTD group with major postoperative morbidity rates of 15.2% (CCRS) and 14.5% (MTD). Five- and 10-year overall survival was 87.4% and 70.3% in the 738 patients who had CCRS compared with 39.2% and 8.1% respectively in the MTD group. On multivariate analysis, significant predictors of reduced overall survival were male gender (p = 0.022), elevated CEA (p = 0.001), elevated CA125 (p = 0.001) and high tumour grade or adenocarcinoma (p = 0.001).

CONCLUSIONS

Perforated epithelial appendiceal tumours are rare, though may be increasing in incidence and can present unexpectedly at elective or emergency abdominal surgery, often with PMP. CRS and HIPEC results in good long term outcomes in most patients.

Pathophysiology and classification of pseudomyxoma peritonei

Background: The term pseudomyxoma peritonei (PMP) was first described in 1884 and there has been much debate since then over the term. A recent consensus of world experts agreed that PMP should be thought of as a clinical entity characterised by the presence of mucinous ascites, omental cake, peritoneal implants and possibly ovarian involvement. It generally originates from mucinous appendiceal tumours. Content: This review details the clinical presentation of this unusual condition, presents the new classification system and how this relates to outcome. The pathophysiology of this disease is also explored with a special reference to the relationship of the disease to tumour markers. Summary: A classification system has been agreed upon by the leading experts in PMP which is now divided into low and high grade mucinous carcinomatosis peritonei. This distinction correlates with clinical outcome as does the presence of raised tumour markers preoperatively. Outlook: Research needs to be focused on understanding the factors associated with poor prognosis through well designed multi-centred prospective studies. This will allow us to identify patients with bad tumour biology so that targeted treatment based on likely prognosis may then become a reality.