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

Abstract

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.

Comprehensive Understanding and Evolutional Therapeutic Schemes for Pseudomyxoma Peritonei

“…In 2020, Chicago Consensus Working Group (CCWG) came to an agreement with the HIPEC regimen with 4 method: (1) Mitomycin, 30 mg at time 0 minutes and 10 mg at time 60 minutes, 90 minutes; (2) Mitomycin at 30 mg/m 2 for 90 to 120 minutes; (3) Mitomycin 15 mg/ m 2 +doxorubicin 15 mg/m 2 , 90 minutes; (4) Oxaliplatin 300 mg/ m 2 , 30 minutes. 50 Since the combination of CRS and HIPEC was pioneered, it has been broadly accepted and has become a standard therapeutic scheme for PMP. According to a young peritoneal center, median OS for observed cases was 100 months, a lower recurrence rate of 18.6% after receiving CRS and HIPEC in contrast to other researches that have covered recrudescence rate in 26.4% to 46%, with a 71% 5-year and 42% 10-year survival.…”

“…Ideal neoadjuvant chemotherapy should be comprised of an alkylating associated with a fluoropyrimidine for around 6 months. 50 But practical experience turns out that neoadjuvant chemotherapy fails to achieve the assumed effect regardless of low-grade or high-grade histology, and additionally put off the time for standard remedy. 60 For conditions that are unresectable or relapse, the chief target for palliative chemotherapy is to delay disease progression and manage symptoms.…”

“…Other intracavitary chemotherapeutic drugs like mitomycin C (MMC), 5-fluorouracil, taxanes are also frequently used. In 2020, Chicago Consensus Working Group (CCWG) came to an agreement with the HIPEC regimen with 4 method: (1) Mitomycin, 30 mg at time 0 minutes and 10 mg at time 60 minutes, 90 minutes; (2) Mitomycin at 30 mg/m 2 for 90 to 120 minutes; (3) Mitomycin 15 mg/m 2 +doxorubicin 15 mg/m 2 , 90 minutes; (4) Oxaliplatin 300 mg/m 2 , 30 minutes 50…”

Prolonged Exposure to Oxaliplatin during HIPEC Improves Effectiveness in a Preclinical Micrometastasis Model

“…The most frequent indication for this treatment has been peritoneal metastasis originating from ovarian cancer or CRC as well as pseudomyxoma peritonei. Accordingly, CRS and HIPEC has recently been shown to improve overall survival in a large cohort study in patients with pseudomyxoma peritonei [ 4 ] and can be considered the standard of care in this rare malignant syndrome [ 5 ]. In spite of long-standing practice, evidence from RCTs was lacking that could confirm survival benefits for adding HIPEC treatment to CRS alone.…”

Tumor-stroma ratio as a new prognosticator for pseudomyxoma peritonei: a comprehensive clinicopathological and immunohistochemical study

“…As a rare clinical tumor syndrome with an indolent clinical course and lack of pathognomonic symptoms, PMP is difficult to diagnose in the early stage, leading to missed diagnosis and misdiagnosis. In addition, the Peritoneal Surface Oncology Group International (PSOGI) consensus on the pathological types of PMP in 2016 ended the controversy and set standards on pathological classification and diagnostic terms of PMP [ 3 , 4 ].…”