Can a Benefit be Expected from Surgical Debulking of Unresectable Pseudomyxoma Peritonei?

Two-stage cytoreductive surgery for 'extensive' pseudomyxoma peritonei: A legitimate alternative or salvage strategy?

BACKGROUND AND AIM

Two-stage cytoreductive surgery (CRS) has been proposed as an alternative to one-stage surgery in patients who have 'extensive' pseudomyxoma peritonei (PMP) and/or are unfit for very extensive surgery, to reduce morbidity. We review current evidence on two-stage CRS focusing on patient selection, interval between procedures, extent of surgery, use of HIPEC, perioperative and oncological outcomes.

METHODS

This is a narrative review. A literature search on PubMed and Embase was performed using keywords- 'Two-stage cytoreductive surgery', 'pseudomyxoma peritonei', 'high-volume PMP', 'huge PMP', 'cytoreductive surgery', 'HIPEC', 'staged surgery' and 'extensive pseudomyxoma peritonei'.

RESULTS

Five studies reported outcomes in a total of 114 patients. The indications for two-stage CRS were: in two studies, patients undergoing an incomplete cytoreduction due to undue surgical risk were reevaluated for a second surgery during routine surveillance; severe comorbidities in one; extensive disease with PCI>28 in another and in one, only HIPEC was performed as a second procedure due to intraoperative hemodynamic instability (the two-stage procedure was performed in interest of patient's safety). Major morbidity ranged from 0 to 37.5 % (first-stage) and 25%-38.9 % (second-stage). Short term follow-up demonstrated equivalent short-term oncological outcomes compared to historical data. Long term follow-up and quality-of-life data were not available.

CONCLUSIONS

The published studies showed different interpretations and applications of the two-stage CRS concept. The reported morbidity was similar to that after single-stage CRS for extensive PMP. Though short-term survival outcomes are acceptable, long-term follow-up is needed. Planned two-stage CRS should currently be reserved for highly selected clinical situations.

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.

Progress in Biological Research and Treatment of Pseudomyxoma Peritonei

Pseudomyxoma peritonei (PMP) is a rare disease characterized by extensive peritoneal implantation and mass secretion of mucus after primary mucinous tumors of the appendix or other organ ruptures. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is currently the preferred treatment, with excellent efficacy and safety, and is associated with breakthrough progress in long-term disease control and prolonged survival. However, the high recurrence rate of PMP is the key challenge in its treatment, which limits the clinical application of multiple rounds of CRS-HIPEC and does not benefit from conventional systemic chemotherapy. Therefore, the development of alternative therapies for patients with refractory or relapsing PMP is critical. The literature related to PMP research progress and treatment was searched in the Web of Science, PubMed, and Google Scholar databases, and a literature review was conducted. The overview of the biological research, treatment status, potential therapeutic strategies, current research limitations, and future directions associated with PMP are presented, focuses on CRS-HIPEC therapy and alternative or combination therapy strategies, and emphasizes the clinical transformation prospects of potential therapeutic strategies such as mucolytic agents and targeted therapy. It provides a theoretical reference for the treatment of PMP and the main directions for future research.

[Surgical treatment for recurrent intra-abdominal mucinous neoplasms]

BACKGROUND

The gold standard in the treatment of mucinous intra-abdominal neoplasms is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Despite complete cytoreduction up to 45% of patients develop recurrences.

METHOD

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

RESULTS

There is still controversy regarding the best treatment strategy for patients with recurrent pseudomyxoma peritonei (PMP) after CRS and HIPEC. The clinical management of these patients depends on many factors, such as the site and volume of recurrence, histological subtype and symptoms. Treatment options range from repeated surgery with curative intent with or without HIPEC to watch and wait strategies. In selected patients redo surgery is feasible and safe with low morbidity and mortality. Iterative complete CRS can result in a median 5‑year overall survival of more than 80%. Debulking surgery leads to a prolonged survival and to symptom control fora period with of nearly 2 years.

CONCLUSION

Repeated complete cytoreduction of recurrent PMP can result in long-term survival. Tumor debulking surgery may be particularly beneficial for symptomatic patients.

Surgical Options for Peritoneal Surface Metastases from Digestive Malignancies-A Comprehensive Review

The peritoneum is a common site for the dissemination of digestive malignancies, particularly gastric, colorectal, appendix, or pancreatic cancer. Other tumors such as cholangiocarcinomas, digestive neuroendocrine tumors, or gastrointestinal stromal tumors (GIST) may also associate with peritoneal surface metastases (PSM). Peritoneal dissemination is proven to worsen the prognosis of these patients. Cytoreductive surgery (CRS), along with systemic chemotherapy, have been shown to constitute a survival benefit in selected patients with PSM. Furthermore, the association of CRS with hyperthermic intraperitoneal chemotherapy (HIPEC) seems to significantly improve the prognosis of patients with certain types of digestive malignancies associated with PSM. However, the benefit of CRS with HIPEC is still controversial, especially due to the significant morbidity associated with this procedure. According to the results of the PRODIGE 7 trial, CRS for PSM from colorectal cancer (CRC) achieved overall survival (OS) rates higher than 40 months, but the addition of oxaliplatin-based HIPEC failed to improve the long-term outcomes. Furthermore, the PROPHYLOCHIP and COLOPEC trials failed to demonstrate the effectiveness of oxaliplatin-based HIPEC for preventing peritoneal metastases development in high-risk patients operated for CRC. In this review, we discuss the limitations of these studies and the reasons why these results are not sufficient to refute this technique, until future well-designed trials evaluate the impact of different HIPEC regimens. In contrast, in pseudomyxoma peritonei, CRS plus HIPEC represents the gold standard therapy, which is able to achieve 10-year OS rates ranging between 70 and 80%. For patients with PSM from gastric carcinoma, CRS plus HIPEC achieved median OS rates higher than 40 months after complete cytoreduction in patients with a peritoneal cancer index (PCI) ≤6. However, the data have not yet been validated in randomized clinical trials. In this review, we discuss the controversies regarding the most efficient drugs that should be used for HIPEC and the duration of the procedure. We also discuss the current evidence and controversies related to the benefit of CRS (and HIPEC) in patients with PSM from other digestive malignancies. Although it is a palliative treatment, pressurized intraperitoneal aerosolized chemotherapy (PIPAC) significantly increases OS in patients with unresectable PSM from gastric cancer and represents a promising approach for patients with PSM from other digestive cancers.

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.

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.

Two-step cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei with high peritoneal carcinomatosis index

BACKGROUND

Complete cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is the only curative treatment for pseudomyxoma peritonei (PMP) arising from the appendix. High peritoneal carcinomatosis index (PCI) is associated with an increased risk of surgical complications. The objective of this study was to present the results of a planned two-step surgical strategy to decrease postoperative morbidity and improve resectability of patients with very high PCI.

METHODS

All consecutive patients who underwent a planned two-step surgical approach for PMP between January 2012 and March 2020 were retrospectively included. This approach was offered for patients with low-grade PMP with PCI > 28 for which feasibility of a complete CRS in one operation was uncertain. The first surgery included a complete CRS of the inframesocolic compartment and omentectomy. HIPEC was delivered at the second surgery, after complete CRS of the supramesocolic compartment. Postoperative morbidity was assessed using the Clavien-Dindo classification and survival results were also collected.

RESULTS

Eight patients underwent the two-step approach. The median PCI was 33 (29-39) and the median time between the two procedures was 111 days (90-212 days). One patient was deemed unresectable at the second surgery. The rate of major morbidity was 0% for the first step and 25% for the second step, with no mortality. Median follow-up was 53.8 months (3-73 months).

CONCLUSION

A two-step surgical management for low-grade PMP patients with very high PCI is safe and feasible, with acceptable postoperative morbidity and no compromise on oncological outcomes.

Evidence-Based Strategies for the Treatment of Peritoneal Malignancies during Health Care Resource Restriction: The COVID-19 Pandemic

Background: The COVID-19 pandemic has put enormous pressure on hospital resources, and has affected all aspects of patient care. As operative volumes decrease, cancer surgeries must be triaged and prioritized with careful thought and attention to ensure maximal benefit for the maximum number of patients. Peritoneal malignancies present a unique challenge, as surgical management can be resource intensive, but patients have limited non-surgical treatment options. This review summarizes current data on outcomes and resource utilization to help inform decision-making and case prioritization in times of constrained health care resources. Methods: A rapid literature review was performed, examining surgical and non-surgical outcomes data for peritoneal malignancies. Narrative data synthesis was cross-referenced with relevant societal guidelines. Peritoneal malignancy surgeons and medical oncologists reviewed recommendations to establish a national perspective on case triage and mitigating treatment strategies. Results and Conclusions: Triage of peritoneal malignancies during this time of restricted health care resource is nuanced and requires multidisciplinary discussion with consideration of individual patient factors. Prioritization should be given to patients where delay may compromise resectability of disease, and where alternative treatment options are lacking. Mitigating strategies such as systemic chemotherapy and/or surgical deferral may be utilized with close surveillance for disease stability or progression, which may affect surgical urgency. Unique hospital capacity, and ability to manage the complex post-operative course for these patients must also be considered to ensure patient and system needs are aligned.

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.

The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis: a systematic review including evidence from Japan

The prognosis of peritoneal carcinomatosis is poor. However, the emergence of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) as a treatment option has prolonged survival and it can even potentially cure patients with peritoneal carcinomatosis. Randomized controlled studies and other observational studies indicated that this combined therapy potentially improved the prognosis of patients with colon, gastric, and ovarian cancers with acceptable morbidity and mortality rates. Even in rarer diseases, such as pseudomyxoma peritonei and malignant peritoneal mesothelioma, CRS + HIPEC markedly improved the prognoses over those with conventional treatment. Based on the accumulated evidence, clinical guidelines recommend CRS + HIPEC for selected patients with peritoneal carcinomatosis. However, several issues still need to be overcome. A standard method for HIPEC has not yet been established. Furthermore, the criteria employed for patient selection need to be clarified to achieve real benefits. The peritoneal cancer index, chemo-sensitivity and several biological markers are considered to be key factors.

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.

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.

History of pseudomyxoma peritonei from its origin to the first decades of the twenty-first century

Pseudomyxoma peritonei (PMP) is a disease surrounded by misunderstanding and controversies. Knowledge about the etymology of pseudomyxoma is useful to remove the ambiguity around that term. The word pseudomyxoma derives from pseudomucin, a type of mucin. PMP was first described in a case of a woman alleged to have a ruptured pseudomucinous cystadenoma of the ovary, a term that has disappeared from today’s classifications of cystic ovarian neoplasms. It is known today that in the majority of cases, the origin for PMP is an appendiceal neoplasm, often of low histological grade. Currently, ovarian tumors are wrongly being considered a significant recognized etiology of PMP. PMP classification continues to be under discussion, and experts’ panels strive for consensus. Malignancy is also under discussion, and it is shown in this review that there is a long-standing historical reason for that. Surgery is the main tool in the treatment armamentarium for PMP, and the only therapy with potential curative option.

Surgical management for peritoneal carcinomatosis of appendiceal origin with a high-tumor burden

PURPOSE

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) is the active treatment for peritoneal carcinomatosis of appendiceal origin. However, surgical management is sometimes difficult in patients with a high-tumor burden.

METHODS

A high-tumor burden was defined as a peritoneal cancer index (PCI) ≥ 28. Among 49 patients receiving CRS + HIPEC, 29 had a PCI ≥ 28.

RESULTS

Complete cytoreduction (CC-0/1) was achieved in 20 of the 29 patients with a PCI ≥ 28 and in all 20 patients with a PCI < 28. Among the patients achieving CC-0/1, gastrectomy or total colectomy was performed more frequently, the hospital stay was longer and postoperative complications were more frequent in those with a PCI ≥ 28 than in those with a PCI < 28. If CC-0/1 was achieved, the overall survival was comparable between patients with a PCI ≥ 28 and a PCI < 28. However, the recurrence-free survival was significantly worse for patients with a PCI ≥ 28 than for those with a PCI < 28 (5-year survival: 73.7% vs. 5.9%). Patients with recurrence who underwent repeat CRS showed a better overall survival than those without repeat CRS. Among patients with a PCI ≥ 28, a performance status (PS) of 2/3 was a significant prognostic factor (hazard ratio = 5.132).

CONCLUSIONS

In patients with a high-tumor burden undergoing CRS + HIPEC, postoperative complications were more frequent, and the recurrence rate was higher than in those without a high-tumor burden. Repeat CRS improved the survival of patients with recurrence. The PS was a key indicator when selecting patients suitable for aggressive resection.

Mucinous appendiceal neoplasms: classification, imaging, and HIPEC

Recent advances, specifically cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), offer advantages compared to the traditional therapeutic approach of systemic chemotherapy in the treatment of peritoneal carcinomatosis from mucinous appendiceal neoplasms (MAN). This review provides an up-to-date, comprehensive summary of the histologic classification of MAN, reviews common imaging findings of mucoceles and pseudomyxoma peritonei, and describes the radiologist's role in the multidisciplinary care team in quantifying disease and in helping select patients for definitive surgery.

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.

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.