Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei of appendicular and extra-appendicular origin

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.

Current clinical practices of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)

Treatment of peritoneal surface malignancies makes physicians face demanding and new-fangled problems, as there are many uncertain aspects considering the outcomes of affected patients' prognoses. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are associated with favorable long-term outcomes in carefully selected patients with peritoneal metastases (PM). We aim to summarize the current results about the initial malignancies and their peritoneal spreads. The current literature has been scrutinized, and studies between 2016 and 2022 were included wherein long-term, progression-free (PFS), and overall survival (OS) data were considered relevant information. Medline, Embase, and Google Scholar have been the main sources. Hereby, we cover all the primer malignancies: gastric, ovarian, and colorectal cancers with peritoneal metastases (PM), malignant peritoneal mesothelioma, and pseudomyxoma peritonei. Examining the advances in the current peer-reviewed literature about the indications of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), target groups, risk factors, and other influencing elements, we intend to provide a complex state-of-the-art report, establishing the relevant aspects of that emerging treatment method.

A case of pseudomyxoma peritonei arising from a perforated intraductal papillary mucinous neoplasm that underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

Pseudomyxoma peritonei (PMP) of pancreatic origin arising from an intraductal papillary mucinous neoplasm (IPMN) is rare. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has been established as the optimal treatment for PMP. However, the benefits and safety of CRS with HIPEC for treating PMP of pancreatic origin remain unclear. Herein, we describe a case of PMP of pancreatic origin that was treated with CRS and HIPEC without postoperative complications. A 75-year-old woman was referred to our department. Computed tomography (CT) revealed a multilocular cystic tumor in the pancreatic tail, notable mucinous ascites in the abdominal cavity, and scalloping of the liver and spleen. CT did not reveal the appendix, and the ovaries were normal in size. The patient was diagnosed with PMP of pancreatic origin, and CRS and HIPEC were performed. Intraoperatively, the pancreatic tumor was perforated, and there was a large amount of mucinous ascites. We performed distal pancreatectomy in addition to CRS and HIPEC, with no intraoperative complications. The postoperative course was uneventful, and the patient survived after 6 months without recurrence. CRS with HIPEC may be a feasible treatment option for PMP of pancreatic origin.

Establishment of a desirable dose using neutral argon plasma to eradicate miliary peritoneal implants: A phase I/II controlled trial

INTRODUCTION

Neutral argon plasma (NAP) system could meet the requirements to achieve oncological cytoreduction of peritoneal carcinomatosis with miliary lesions, minimizing the associated morbidity. This phase I/II trial aims to establish the desirable dose that is safe and effective in eliminating tumor cells with lower penetration.

METHODS

Patients diagnosed with different origins for peritoneal carcinomatosis and miliary implants were selected for the study. The safe and potentially effective dose (desirability) of NAP was evaluated according to three factors: distance (mm), application time (s) and power (%), to evaluate the response variables such as the presence of tumor cells (Y/N) and the depth of penetration.

RESULTS

Ten patients and 120 samples were evaluated and treated with NAP. There was no vascular or organ injury intraoperative using a pre-established dose of 100% (coagulation mode) at a distance of 2-3 cm. The distance was found to be correlated with the presence of the tumor cells in ex-vivo analysis, with an OR of 15.4 (4.0-111.4). The time and energy used were protective factors to eliminate tumor cells with an OR of 0.4 (0.1-0.9) and 0.8 (0.8-0.9), respectively. The safest and most effective desirability results were as follows i) energy 80% during 2-4 s with a distance of 2 cm (0.89), and ii) energy 100% during 2-4 s with a distance of 3 cm (0.90).

CONCLUSIONS

The use of NAP during a CRS and HIPEC is safe and effective for eradicating tumor cells on the peritoneal surface at suggested doses of energy, distance and duration.

TRIAL IDENTIFICATION

ClinicalTrials.gov Identifier: NCT04904042.

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.

Histopathological Evaluation and Molecular Diagnostic Tests for Peritoneal Metastases with Unknown Primary Site-a Review

Cancer of unknown primary (CUP) is a well-studied entity with guidelines available for the management of patients with CUP. The peritoneum represents one of the metastatic sites in CUP, and peritoneal metastases (PM) could present as CUP. PM of unknown origin remains a poorly studied clinical entity. There is only one series of 15 cases, one population-based study, and few other case reports on this subject. Studies on CUP, in general, cover some common tumour histological types like adenocarcinomas and squamous carcinomas. Some of these tumours may have a good prognosis though majority have high-grade disease with a poor long-term outcome. Some of the histological tumour types commonly seen in the clinical scenario of PM like mucinous carcinoma have not been studied. In this review, we divide PM into five histological types-adenocarcinomas, serous carcinomas, mucinous carcinomas, sarcomas and other rare varieties. We provide algorithms to identify the primary tumour site using immunohistochemistry when imaging, and endoscopy fails to establish the primary tumour site. The role of molecular diagnostic tests for PM or unknown origin is also discussed. Current literature on site-specific systemic therapy based on gene expression profiling does not show a clear benefit of this approach over empirical systemic therapies.

An Asian Tertiary Centre's Early Experience with Laparoscopic Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis

The use of open cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown improved oncological survival in terms of treating peritoneal surface malignancies (PSM). However, this procedure often comes with associated morbidity. The move towards use of laparoscopic surgery in this field is postulated to lead to a reduction in morbidity and earlier return to function, but literature on its use for CRS and HIPEC has been scarce. We performed a retrospective review of 6 patients with PSM who underwent laparoscopic CRS and HIPEC in our institution and analysed the patient characteristics, oncological history, perioperative and postoperative outcomes. Median peritoneal cancer index (PCI) score was 0 (IQR 0-1.25). All 6 patients had appendiceal primaries. Median operative time was 285 min (IQR 228.8-300); median length of stay was 7.5 days (IQR 5-8.8). All patients achieved complete cytoreduction, and there was no conversion to open surgery. One patient developed port site infection and another 2 patients subsequently developed adhesions. Median follow-up time was 35 (IQR 17.5-41) months. No patients had developed recurrence at the time of data collection. We conclude that in patients with limited PCI sore (< 2), laparoscopic CRS and HIPEC are safe and feasible. With increasing experience, a select group of patients with limited PSM may be treated via minimally invasive surgery, minimising the morbidity of a traditional laparotomy.

Determining a minimum data set for reporting clinical and radiologic data for pseudomyxoma peritonei

Objectives

Pseudomyxoma peritonei (PMP) is a rare cancer currently affecting over 11,736 patients across Europe. Since PMP is so uncommon, collaboration between scientific centers is key to discovering the mechanisms behind the disease, efficient treatments, and targets pointing to a cure. To date, no consensus has been reached on the minimum data that should be collected during PMP research studies. This issue has become more important as biobanking becomes the norm. This paper begins the discussion around a minimum data set that should be collected by researchers through a review of available clinical trial reports in order to facilitate collaborative efforts within the PMP research community.

Content

A review of articles from PubMed, CenterWatch, ClinicalTrials.gov and MedRxiv was undertaken, and clinical trials reporting PMP results selected.

Summary

There is a core set of data that researchers report, including age and sex, overall survival, peritoneal cancer index (PCI) score, and completeness of cytoreduction, but after this, reports become variable.

Outlook

Since PMP is a rare disease, it is important that reports include as large of a number of standardised data points as possible. Our research indicates that there is still much ground to cover before this becomes a reality.

Effect of standardized fluid management on cardiac function after CRS + HIPEC in patients with PMP: a single-center case-control study

OBJECTIVE

To investigate the effects of standardized fluid management (SFM) on cardiac function in patients with pseudomyxoma peritonei (PMP) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHOD

Patients with PMP who underwent CRS + HIPEC at our center were retrospectively analyzed. The patients were divided into control and study groups according to whether SFM was applied after CRS + HIPEC. We compared the preoperative and postoperative cardiac and renal function parameters, daily fluid volume three days after CRS, and cardiovascular-related adverse events. Univariate and multivariate analyses were performed to identify the indicators affecting clinical prognosis.

RESULT

Among the 104 patients, 42 (40.4%) were in the control group and 62 (59.6%) in the study group. There were no statistically significant differences between the two groups in the main clinicopathological characteristics, preoperative cardiac and renal function parameters, and CRS + HIPEC-related indicators. The incidences of cardiac troponin I (CTNI) > upper limit of normal (ULN), >2 × ULN, >3 × ULN, serum creatinine > ULN, and blood urea nitrogen > ULN were higher in the control group than in the study group (p < 0.05). The median daily fluid volume of the control group was higher than that of the study group 3 days after CRS (p < 0.05). Postoperative CTNI > 2 × ULN was an independent risk factor for serious circulatory adverse events. Survival analysis revealed pathological grading, completeness of cytoreduction score, and postoperative CTNI > ULN as independent prognostic factors.

CONCLUSIONS

SFM after CRS + HIPEC in patients with PMP may reduce cardiovascular adverse events risk and improve clinical outcomes.

[Current treatment recommendations for pseudomyxoma peritonei]

BACKGROUND

The term pseudomyxoma peritonei (PMP) describes a clinical syndrome characterized by the presence of gelatinous intraperitoneal accumulation of mucus. It mostly originates from a mucocele of the vermiform appendix. Affected patients are often asymptomatic for a long time. Because of its indolent nature it is usually diagnosed at an advanced stage. Clinical presentation is determined by the dissemination of the tumor.

METHOD

A search and analysis of the current literature were carried out.

RESULTS

Based on the morphological characteristics PMP subtypes with various malignant potential can be differentiated. The prognosis depends on the histopathological differentiation and the clinical stage. The treatment spectrum varies from laparoscopic appendectomy to complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC).

CONCLUSION

Due to the rarity of PMP there are no prospective randomized studies. Therefore, there is still controversy regarding the best stage-dependent treatment strategy. This review article attempts to clarify the optimal management of mucinous neoplasms of the appendix and PMP taking the clinical presentation and the histological differentiation into consideration.

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.

Comprehensive Treatment Algorithms of the Swiss Peritoneal Cancer Group for Peritoneal Cancer of Gastrointestinal Origin

Peritoneal cancer (PC) is a dire finding, yet in selected patients, long-term survival is possible. Complete cytoreductive surgery (CRS) together with combination immunochemotherapy is essential to achieve cure. Hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are increasingly added to the multimodal treatment. The Swiss Peritoneal Cancer Group (SPCG) is an interdisciplinary group of expert clinicians. It has developed comprehensive treatment algorithms for patients with PC from pseudomyxoma peritonei, peritoneal mesothelioma, gastric, and colorectal origin. They include multimodal neoadjuvant treatment, surgical resection, and palliative care. The indication for and results of CRS HIPEC and PIPAC are discussed in light of the current literature. Institutional volume and clinical expertise required to achieve best outcomes are underlined, while inclusion of patients considered for CRS HIPEC and PIPAC in a clinical registry is strongly advised. The present recommendations are in line with current international guidelines and provide the first comprehensive treatment proposal for patients with PC including intraperitoneal chemotherapy. The SPCG comprehensive treatment algorithms provide evidence-based guidance for the multimodal care of patients with PC of gastrointestinal origin that were endorsed by all Swiss clinicians routinely involved in the multimodal care of these challenging patients.

Survival prediction by Bayesian network modeling for pseudomyxoma peritonei after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy

OBJECTIVES

To establish a survival prognostic model for pseudomyxoma peritonei (PMP) treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) based on Bayesian network (BN).

METHODS

453 PMP patients were included from the database at our center. The dataset was divided into a training set to establish BN model and a testing set to perform internal validation at a ratio of 8:2. From the training set, univariate and multivariate analyses were performed to identify independent prognostic factors for BN model construction. The confusion matrix, receiver operating characteristic (ROC) curve and the area under curve (AUC) were used to evaluate the performance of the BN model.

RESULTS

The univariate and multivariate analyses identified 7 independent prognostic factors: gender, previous operation history, histological grading, lymphatic metastasis, peritoneal cancer index, completeness of cytoreduction and splenectomy (all p < 0.05). Based on independent factors, the BN model of training set was established. After internal validation, the accuracy and AUC of the BN model were 70.3% and 73.5%, respectively.

CONCLUSION

The BN model provides a reasonable level of predictive performance for PMP patients undergoing CRS + HIPEC.

Comprehensive Understanding and Evolutional Therapeutic Schemes for Pseudomyxoma Peritonei: A Literature Review

Pseudomyxoma peritonei is an infrequent solid tumor in clinical practice. The low morbidity and deficient understanding of this mucus-secreting malignant disease increase the risks of delayed identification or uncontrollable deterioration. In quite a lot cases, patients go through complete cytoreduction surgery and hyperthermic intraperitoneal chemotherapy could receive a long time survival over 5 years. But the recurrence rate is also hard to overlook. Unlike other types of cancer, the standard treatment for this considerable groups has not been confirmed yet. With the advanced medical progression, studies have been carrying out based on pathogenesis, biological characters, and mutated gene location. All but a few get statistical survival benefits, let alone the breaking progress on research or therapeutic practice in the field. We try to give a comprehensive exposition of pseudomyxoma peritonei around the epidemiology, radiologic features, clinical manifestation, present treatment and promising schemes, hoping to arise much attention and reflection on the feasible solutions, especially for the recrudescent part.

Primary and metastatic peritoneal surface malignancies

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Prognostic Value of CEA, CA19-9, CA125, CA724, and CA242 in Serum and Ascites in Pseudomyxoma Peritonei

Purpose

To investigate the expression of carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), CA19-9, CA724, and CA242 in serum and ascites of pseudomyxoma peritonei (PMP) patients and evaluate the predictive value of these elevated biomarkers in pathological grade, completeness of cytoreduction (CC), and survival.

Methods

From May 2009 to October 2019, a total of 512 patients diagnosed with PMP through pathology in Aerospace Center Hospital were enrolled. The serum and ascites tumor biomarkers were obtained. The diagnostic values between serum and ascites biomarkers in pathology and CC were compared by the receiver operating characteristic (ROC) curves. The correlation between pathology, cytoreduction, and biomarkers was calculated by univariate and multivariate logistic regression. The associations between different numbers of elevated biomarkers and survival status were examined using univariate and multivariate backward Cox proportional hazard regression models.

Results

The results showed that the areas under the ROC curves (AUROC) in the diagnosis of CC were 0.798 (95% CI: 0.760-0.836) and 0.632 (95% CI: 0.588-0.676) in serum and ascites biomarkers, respectively. The elevated serum and ascites biomarkers were independent risk factors for both pathology and CC. The 1-year, 3-year, and 5-year survival rates were 89.07%, 73.22%, and 66.94%, respectively. Longer survival was observed in patients who had less than two elevated serum biomarkers compared with those with 2-3 and 4-5 elevated serum biomarkers (p < 0.001).

Conclusion

CEA, CA125, CA19-9, CA724, and CA242 in serum and ascites can be used to judge the severity and predict the resectability. Furthermore, different numbers of elevated biomarkers can help determine the prognosis of PMP.

The Utility of Preoperative Tumor Markers in Peritoneal Carcinomatosis from Primary Appendiceal Adenocarcinoma: an Analysis from the US HIPEC Collaborative

BACKGROUND

Prognostication based on preoperative clinical factors is lacking in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). This study aims to determine the value of preoperative tumor markers as predictors of progression-free survival (PFS) and overall survival (OS) for patients with peritoneal carcinomatosis from a primary mucinous adenocarcinoma of the appendix (MACA).

METHODS

We queried the United States HIPEC Collaborative, a database of patients with peritoneal carcinomatosis treated with CRS/HIPEC at twelve institutions between 2000 and 2017, identifying 409 patients with MACA. Multivariate analysis was used to identify independent predictors of disease progression. Subgroup analysis was conducted to evaluate the impact of tumor grade on the predictive value of tumor markers.

RESULTS

CA19-9 [HR 2.44, CI 1.2-3.4] emerged as an independent predictor of PFS while CEA [HR 4.98, CI 1.06-23.46] was independently predictive of OS (p <0.01). Tumor differentiation was the most potent predictor of both PFS (poorly differentiated vs well, [HR 4.5 CI 2.01-9.94]) and OS ([poorly differentiated vs well-differentiated: [HR 13.5, CI 3.16-57.78]), p <0.05. Among patients with combined CA19-9 elevation and poorly differentiated histology, 86% recurred within a year of CRS/HIPEC (p < 0.01). Similarly, the coexistence of CEA elevation and unfavorable histology led to the lowest survival rate at two years [36%, p < 0.01]. CA-125 was not predictive of PFS or OS.

CONCLUSION

Elevated preoperative CA19-9 portends worse PFS, while elevated CEA predicts worse OS after CRS/HIPEC in patients with MACA. This study provides additional evidence that CA19-9 and CEA levels should be collected during standard preoperative bloodwork, while CA-125 can likely be omitted. Tumor differentiation, when added to preoperative tumor marker levels, provides powerful prognostic information. Prospective studies are required to confirm this association.

Rare primary peritoneal mucinous adenocarcinoma in a 69-year-old man

Primary peritoneal mucinous adenocarcinoma is rare in men. The low-grade tumor consisted of mucin-producing columnar cells with minimal nuclear atypia. Relationship to pseudomyxoma peritonei and disseminated peritoneal adenomucinosis is discussed.

A Proposal for Modification of the PSOGI Classification According to the Ki-67 Proliferation Index in Pseudomyxoma Peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare malignancy, classified according to the Peritoneal Surface Oncology Group International (PSOGI) classification, whose response to treatment remains highly heterogeneous within the high-grade (HG) category. Molecular profiling of PMP cases might help to better categorize patients and predict treatment responses.

METHODS

We studied the Ki-67 proliferation rate and P53 overexpression in tissue samples from our historical cohort of HG-PMP patients. We established as cut-off levels the third quartile of each marker to perform univariate and multivariate Cox regression survival analyses. According to these results, the HG-PMP category was divided into subcategories and a new survival analysis was performed.

RESULTS

A total of 90/117 patients with PMP undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) were selected for secondary analysis. The survival analysis of the HG-PMP category for preoperative variables showed that a proliferation index defined by Ki-67 >15% is a bad prognostic factor, with a hazard ratio (HR) of 3.20 (95% confidence interval [CI] 1.24-8.25). Accordingly, the HG-PMP group was divided using the Ki-67 15% cut-off. The new PSOGI/Ki-67 variable was an independent prognostic factor for overall survival (OS), with an HR of 3.74 (95% CI 1.88-7.47), and disease-free survival (DFS), with an HR of 4.184 (95% CI 1.79-9.75). The estimated 5-year OS rate was 100%, 70% and 24% for the LG-PMP, HG-PMP ≤15% and HG-PMP >15% groups, respectively (p = 0.0001), while the 5-year DFS rate was 90%, 44% and 0%, respectively (p = 0.0001).

CONCLUSION

Division of the HG-PMP category of the PSOGI classification, according to the Ki-67 proliferation index, provides two well-defined subcategories, with significant differences in terms of OS and DFS, and hence high prognostic value.

Complete pathologic response after two-stage cytoreductive surgery with HIPEC for bulky pseudomyxoma peritonei: proof of concept

Introduction: Pseudomyxoma peritonei (PMP) is a rare disease characterized by the progressive accumulation of mucinous ascites and peritoneal implants. The optimal treatment for PMP includes the association of complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). For patients with a large burdensome disease, the completeness of cytoreduction sometimes requires maximal effort surgery. The aim of this article is to provide proof of concept for two stage cytoreductive surgery (CRS) in this category of patients.Methods and materials: A two stage CRS and HIPEC with oxaliplatin was proposed for patients with bulky PMP including important involvement of the serosal surfaces of the bowel or colon who had an impaired nutritional status. The residual disease at the end of the first stage was less than 5 mm of thickness on several implants. Clinical, surgical and histopathological variables were analyzed.Results: All eight patients completed the two-stage strategy. Mortality was nil. One Clavien Dindo grade 3 event occurred in each stage. After a median follow up of 29.5 months, all patients were alive and free of recurrence. All of the patients had histopathological complete response on the specimens obtained from the residual sites during the second stage surgery.Conclusions: Two-stage surgical strategy is feasible for bulky PMP patients and it is associated with little high-grade morbidity and enhanced visceral sparing.

Clinicopathological Characteristics and Prognostic Prediction in Pseudomyxoma Peritonei Originating From Mucinous Ovarian Cancer

Objective

To describe the clinicopathological characteristics of mucinous ovarian cancer (MOC)-derived pseudomyxoma peritonei (PMP) and identify prognostic factors for survival.

Methods

Medical records from patients with MOC-derived PMP who attended the Aerospace Center Hospital, Beijing, China between January 2009, and December 2019 were retrospectively reviewed. Survival analysis was performed with the Kaplan-Meier method, the log-rank test, and a Cox proportional hazards model.

Results

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP originating from MOC were performed on 22 patients, who had a median age of 52 years at the time of surgery. At the last follow-up in June 2020, 9 (41%) patients were still alive. Median OS was 12 months (range, 1 to 102 months), and the 2-, 3-, and 5-year survival rates were 23, 9, and 5%, respectively.

Conclusion

Histopathologic subtype and PCI may be applied as predictors of prognosis in patients with MOC-derived PMP. Patients with high-grade disease could benefit from completeness of cytoreduction (CCR) 0/1.

New insights in the pathology of peritoneal surface malignancy

Pathology is central to the management of peritoneal surface malignancy. This article highlights some recent advances that have had an impact on patient management or could do so in the near future. Malignant peritoneal mesothelioma, particularly the epithelioid subtype, is amenable to radical therapy in selected cases, and factors such as ki67 proliferation index, expression of BAP1 and mutation in CDKN2A show promise as prognostic indicators. Our understanding of multicystic mesothelioma has improved in recent years; it is a true neoplasm for which surgery may be indicated. Serous carcinomas involving the peritoneum are now known to originate from tubal epithelium. They are of two distinct types, high grade and low grade, which are now recognized as different neoplasms with distinctive features, oncogenesis and behavior. Pseudomyxoma peritonei (PMP) is an unusual condition that usually arises from an appendiceal mucinous neoplasm. Recent consensus in the classification and nomenclature of these lesions is discussed, including the distinction between low grade and high grade appendiceal mucinous neoplasms (HAMN), and the diagnostic criteria for appendiceal adenocarcinoma. PMP is divided into four prognostic groups: acellular mucin, low grade mucinous carcinoma peritonei, high grade mucinous carcinoma peritonei, and high grade mucinous carcinoma peritonei with signet ring cells. The pseudomyxoma microbiome is a promising area for clinical intervention but has been the subject of little research activity. Goblet cell adenocarcinoma (previously known as 'goblet cell carcinoid') is a distinctive type of appendiceal adenocarcinoma. Its behavior correlates with histologic features, but no general consensus for classification has been reached.

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.

From the Ronnett to the PSOGI Classification System for Pseudomyxoma Peritonei: A Validation Study

BACKGROUND

Several classifications have been used for pseudomyxoma peritonei (PMP), and among these, the Ronnett classification is the most commonly used. However, a new consensual Peritoneal Surface Oncology Group International (PSOGI) classification has recently been proposed. Nonetheless, to date, the ability of the PSOGI classification to predict survival based on its different disease histologic categories has not been validated.

METHODS

This study enrolled 117 patients with PMP who had undergone cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) between 1997 and 2020. Cox proportional hazards regression models and time-dependent curve receiver operating characteristic (ROC) analyses were used to assess the predictive capacity of both classification systems for the overall survival (OS) and disease-free survival (DFS) of these patients.

RESULTS

Significant differences in the 5-year OS rate were found for the different histologic grades according to each of the classifications. The completeness of cytoreduction score (CCS) was identified as a factor that predicted patient OS prognosis (p = 0.006). According to the time-dependent ROC curves at the "100" time point, adjusted by the CCS and DFS, the capacity to predict OS was optimal and achieved an area under the curve (AUC) of about 69% for OS and approximately 62% for DFS.

CONCLUSIONS

Both the Ronnett and PSOGI classifications were able to predict survival optimally for this patient cohort. However, when the classifications were adjusted by the CCS, the predictive availability for OS was better with the PSOGI classification than with the Ronnett classification.

Clinical and predictive value of blood lactate levels during cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC): a comparative analysis

Postoperative outcome after cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is strongly related to surgical and anesthesiologic expertise. This study aims to evaluate the clinical significance and prognostic value of lactate levels (LL) measured during CRS-HIPEC on postoperative outcome compared to similar major surgical procedures. Patients who were treated between January and September 2019 at our Institute and met the inclusion criteria were selected. Patients were divided into three groups: group 1: patients who underwent major surgical procedures; group 2: patients who underwent CRS without HIPEC; group 3: patients who underwent CRS with HIPEC. Intraoperative LL were analyzed and correlated with surgical procedure and postoperative outcome. We observed a significant increase of LL during surgical/CRS phase (group 1: p = 0.0001; group 2: p = 0.001; group 3: p = 0.057), rather than during the HIPEC phase in group 3 (p = ns). In patients undergoing CRS and peritonectomies, the mean LL were significantly higher compared to group 1 (p = 0.05). Although not statistically significant, the complication rate was higher in patients with end-CRS lactate values > 2 mMol/l, especially in the group undergoing CRS plus HIPEC. Our pilot study shows that higher LL during peritoneal cancer surgery are expected compared to major surgical procedures. Cytoreductive phase, rather than HIPEC, is related to an increase of LL. The role of LL as an early marker of postoperative complications after CRS-HIPEC should be further verified in properly designed studies.

Immunohistochemical staining as supportive diagnostic tool for pseudomyxoma peritonei arising from intraductal papillary mucinous neoplasm: A report of two cases and literature review

BACKGROUND/OBJECTIVES

Pseudomyxoma peritonei (PMP) arising from an intraductal papillary mucinous neoplasm of the pancreas (IPMN) is a rare condition. The diagnosis of IPMN as the origin of PMP is mainly inferred from the clinical course and the exclusion of PMP from other organs. The pathological diagnosis has not yet been established. To evaluate the usefulness of immunohistochemical staining for the diagnosis of the primary lesion of PMP as IPMN.

METHODS

There are 2 cases of PMP arising from IPMN between March 2010 and December 2019 at National Center for Global Health and Medicine. A PubMed search that reported PMP arising from IPMN identified 16 additional cases. Diagnostic methods and clinicopathological features of 18 cases were compared.

RESULTS

Four cases including our two cases used immunohistochemical staining for the diagnosis of PMP arising from IPMN. The correspondence of the immunohistochemical staining between PMP and IPMN was shown in the three cases including previously reported two cases and one of our two cases to identify the primary lesion of PMP as IPMN. In addition, we revealed that the comparison of the immunostaining pattern of PMP with the representative immunostaining pattern of the candidate primary lesions is helpful for the diagnosis of the primary lesion of PMP.

CONCLUSIONS

Immunohistochemical staining is helpful to identify the primary lesion of PMP as IPMN.

Updates in Appendix Pathology: The Precarious Cutting Edge

Mucinous appendiceal tumors include low-grade appendiceal mucinous neoplasm, high-grade appendiceal mucinous neoplasm, and mucinous adenocarcinoma. Nonmucinous adenocarcinomas are less frequent. Recent consensus guidelines and the latest edition of the World Health Organization classification will allow consistent use of agreed nomenclature. Accurate diagnosis is important not only for patient management but also to allow comparison of results between centers and tumor registries. Serrated polyps are the most common benign polyp in the appendix. They need to be distinguished from low-grade appendiceal mucinous neoplasm, which can also mimic other benign conditions. Goblet cell adenocarcinomas are a distinctive type of appendiceal neoplasm.

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in pseudomyxoma peritonei of appendiceal origin: result of a single centre study

Pseudomyxoma peritonei (PMP) is a rare condition characterized by the intraperitoneal accumulation of mucus derived mostly by appendiceal mucinous neoplasm. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can offer a favourable overall survival. In this study, we report a single-institute outcomes following CRS and HIPEC in patients with this condition. This is a review of prospectively collected data from 32 patients (11 men and 21 women) affected by PMP of appendiceal origin who underwent CRS and HIPEC from 2008 to 2016 in our Surgical Unit of General and Esophagogastric Surgery. The median age of the patients was 53 years (range 25-77 years). After CRS, all patients underwent HIPEC (mytomicin C 3.3 mg/m²/L and cisplatin 25 mg/m²/L at 41 °C for 60 min) with closed abdomen technique. The median (range) follow-up time for surviving patients was 43 (18-119) months. The median peritoneal cancer index (PCI) was 17. Complete cytoreductive surgery (CC0) was achieved in in 22 patients (69%). The majority of patients (88%) had grade I-II complications, 3 (9%) had grade III complications, and 1 (3%) patient had a grade IV complication. There were no perioperative mortalities. The median hospital stay was 9.5 (range 9-24) days. One year and 5-year overall survival (OS) were 90% and 58%, respectively. Regardless of histotype, disease-free survival was 95% at 1 year and 46% at 5 years. CRS in combination with HIPEC is a feasible treatment strategy and can achieve a satisfactory outcome in patients with PMP of appendiceal origin.

The Chicago Consensus on Peritoneal Surface Malignancies: Management of Ovarian Neoplasms

The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of ovarian neoplasms specifically related to the management of peritoneal surface malignancy. These guidelines are developed with input from leading experts including surgical oncologists, medical oncologists, gynecologic oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence.

The Chicago Consensus on peritoneal surface malignancies: Management of ovarian neoplasms

The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of ovarian neoplasms specifically related to the management of peritoneal surface malignancy. These guidelines are developed with input from leading experts, including surgical oncologists, medical oncologists, gynecologic oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence.

Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy by laparoscopy via a single-port approach for low-grade peritoneal malignancy

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a long and complex procedure. A minimal invasive approach is rarely performed. The feasibility of laparoscopic CRS and HIPEC via a single port (SP) approach is unknown. The aim of this study was to assess the feasibility of CRS and HIPEC with a SP approach.

METHODS

This study is IDEAL stage I-IIa. Patients with low grade and limited peritoneal malignancy were included in a tertiary care cancer center. Intra- and post-operative adverse events were recorded and classified according to medical and surgical dedicated classifications. The main objective measurement to assess feasibility was the conversion to open or multiport surgery.

RESULTS

A total of 12 highly selected patients were assessed. The median operating time was 240 min (range, 180-360) and two near miss events were reported. Two conversions to open and multiport surgery occurred. The median comprehensive complication index was 0 (range, 0-42.6) with two severe adverse events (Clavien-Dindo or CTC-AE ≥ 3). The median length of stay was 8.5 days (range, 5-13).

CONCLUSION

CRS and HIPEC via a laparoscopic SP approach are feasible and safe in the short term. The next step should be a prospective development study.

Efficacy of modified FOLFOX6 chemotherapy for patients with unresectable pseudomyxoma peritonei

Background

Pseudomyxoma peritonei (PMP) is a rare malignancy, and there is insufficient evidence about systemic chemotherapy for this disease.

Methods

We retrospectively evaluated the efficacy and safety of a chemotherapeutic regimen with 5-fluorouracil and oxaliplatin (modified FOLFOX6, mFOLFOX6) for patients with unresectable pseudomyxoma peritonei. Patients who received the therapy between April 2000 and February 2019 at the Department of Medical Oncology, Tohoku University Hospital, were enrolled in this study.

Results

Eight patients were treated with mFOLFOX6. The sites of primary tumor were appendix in six patients, ovary in a patient, and urachus in a patient. Six patients received surgery. Seven patients had histologically high-grade PMP, and one patient had low-grade PMP. The median follow-up duration was 27.2 months. All the patients had non-measurable regions as the targets of tumor response. Non-complete response or non-progressive disease was observed in seven patients, with a disease control rate of 87.5%. The median progression-free survival and overall survival were 13.0 months and 27.9 months, respectively. An obvious reduction in the symptoms was observed in two patients. Five patients experienced decline in the serum tumor markers, CEA or CA19-9. The grade 3/4 toxicity that was observed was grade 4 neutropenia in one patient and grade 3 neutropenia in two patients.

Conclusions

mFOLFOX6 might be an effective and tolerable treatment option for patients with unresectable PMP. To our knowledge, this is the first case series of mFOLFOX6 in patients with unresectable PMP and the first case series of systemic chemotherapy for Asian patients with unresectable PMP.

Electronic supplementary material

The online version of this article (10.1007/s10147-019-01592-x) contains supplementary material, which is available to authorized users.

Preoperative Risk Score for Predicting Incomplete Cytoreduction: A 12-Institution Study from the US HIPEC Collaborative

BACKGROUND

For patients with peritoneal carcinomatosis undergoing cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC), incomplete cytoreduction (CCR2/3) confers morbidity without survival benefit. The aim of this study is to identify preoperative factors which predict CCR2/3.

METHODS

All patients who underwent curative-intent CRS/HIPEC of low/high-grade appendiceal, colorectal, or peritoneal mesothelioma cancers in the 12-institution US HIPEC Collaborative from 2000 to 2017 were included (n = 2027). The primary aim is to create an incomplete-cytoreduction risk score (ICRS) to predict CCR2/3 CRS utilizing preoperative data. ICRS was created from a randomly selected cohort of 50% of patients (derivation cohort) and verified on the remaining patients (validation cohort).

RESULTS

Within our derivation cohort (n = 998), histology was low-grade appendiceal neoplasms in 30%, high-grade appendiceal tumor in 41%, colorectal tumor in 22%, and peritoneal mesothelioma in 8%. CCR0/1 was achieved in 816 patients and CCR 2/3 in 116 patients. On multivariable analysis, preoperative factors associated with incomplete cytoreduction were male gender [odds ratio (OR) 3.4, p = 0.007], presence of ascites (OR 2.8, p = 0.028), cancer antigen (CA)-125 ≥ 40 U/mL (OR 3.4, p = 0.012), and carcinoembryonic antigen (CEA) ≥ 4.2 ng/mL (OR 3.2, p = 0.029). Each preoperative factor was assigned a score of 0 or 1 to form an ICRS from 0 to 4. Scores were grouped as zero (0), low (1-2), or high (3-4). Incidence of CCR2/3 progressively increased by risk group from 1.6% in zero to 13% in low and 39% in high. When ICRS was applied to the validation cohort (n = 1029), this relationship was maintained.

CONCLUSION

The incomplete cytoreduction risk score incorporates preoperative factors to accurately stratify the risk of CCR2/3 resection in CRS/HIPEC. This score should not be used in isolation, however, to exclude patients from surgery.

Liver scalloping: Pseudomyxoma peritonei liver compression

Pseudomyxoma peritonei is a rare tumor characterized by the presence of mucous disseminated throughout the peritoneal cavity generally arising from the rupture of an appendicular mucocele. Liver scalloping is a highly suggestive image of pseudomyxoma and corresponds to the indentation of the liver compressed by the gelatinous mucin.

Abdominal hernia and the unexpected final diagnosis

Mucinous neoplasm of the appendix are rare entities, among these, mucinous cystadenomas contribute to 31–34%. Cystadenomas often produce extensive dilatation of the appendix with epithelial atypia. Spontaneous perforation often occurs in 20%, leading to mucin distribution throughout the peritoneal cavity. Half of the patients are completely asymptomatic and are detected as an incidental diagnosis, others symptoms include a palpable mass, hernias, weight loss, peritonism or even intestinal obstruction. We present a case of a 71-year-old female, she presented with a palpable mass in the upper abdomen. A ventral hernia was the most likely diagnosis and hernioplasty was planned. At surgery, a mucinous mass was discovered and mucous material was found free en the peritoneal cavity. Also, a perforated appendix and a mass in the cecum was found. Patient underwent full recovery. Pathology reported pseudomyxoma peritonei as the final diagnosis.