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Biomedicines Jul 2023In pseudomyxoma peritonei (PMP), and mutations are frequent. We hypothesized that these mutations may contribute to the suppression of antitumor immunity: may induce...
In pseudomyxoma peritonei (PMP), and mutations are frequent. We hypothesized that these mutations may contribute to the suppression of antitumor immunity: may induce GMCSF expression, while may enhance the expression of cyclic adenosine monophosphate and A2AR signaling. This study aimed to explore possible mechanisms facilitated by and mutations for escaping immune surveillance. Additionally, we looked for new potential therapeutic and prognostic targets in this rare disease which is poorly characterized at the molecular level. GM-CSF, A2AR, CD73, CD39, and PD-L1 expression was investigated by immunohistochemistry in 40 PMPs characterized for and mutational status. Immune cell populations were studied by immunohistochemistry and nanostring nCounter. Following the criteria of a prognostic nomogram reported for PMP, we stratified the patients into two different risk groups, with 28 "low-risk" and 12 "high-risk" patients. We observed the expression of GM-CSF (74%); CD39 (37%); CD73 (53%); A2AR (74%); and PD-L1 (16%) which was unrelated to or status. The tumor microenvironment showed the presence of CD4+ T cells (86%); CD8+ T cells (27%); CD20+ B (67%); CD15+ cells (86%); and CD163+ M2 macrophages (67%), while CD56+ NK cells were absent. CD163 expression (27%) in PMP tumor cells was associated with poor prognosis. mutation and A2AR expression were not associated with a specific immune transcriptional signature. However, the expression assay revealed 21 genes associated with prognosis. The "high-risk" patients exhibited worse progression-free survival (HR = 2.3, CI 95%: 1.1-5.1, = 0.034) and significant downregulation of , , , , , and . In conclusion, we documented the presence of immunosuppressive factors such as GM-CSF, A2AR, and PD-L1 in PMP. These factors were not associated with and status and could be explored as therapeutic molecular targets. Additionally, a set of potential prognostic biomarkers, including CD163 expression in tumor cells, deserve further investigation.
PubMed: 37509688
DOI: 10.3390/biomedicines11072049 -
Current Oncology (Toronto, Ont.) May 2022Pseudomyxoma peritonei (PMP) is a rare clinical syndrome. It originates from neoplasms of the appendix and leads to the formation of peritoneal implants and the... (Review)
Review
Pseudomyxoma peritonei (PMP) is a rare clinical syndrome. It originates from neoplasms of the appendix and leads to the formation of peritoneal implants and the accumulation of mucinous ascites. PMP represents a spectrum of low to high-grade disease. Despite aggressive management, many PMP patients recur, leading to debilitating symptoms and few treatment options. Therefore, scientists have continued to look for ways to improve treatment and further understand disease pathogenesis. Microorganisms were previously hypothesized to play a role in PMP progression and development. Hence, antibacterial treatment was suggested by some authors, but the data were limited. In this paper, we review the current data on the role of bacteria in PMP, discuss the significance, and suggest possible solutions to the inherent challenges in these studies. Given the limitations of the discussed studies, we remain skeptical about introducing novel antibacterial treatment into clinical practice at this time; however, the available data are valuable and indicate that more research into the molecular mechanisms of PMP is needed.
Topics: Appendiceal Neoplasms; Appendix; Humans; Neoplasm Recurrence, Local; Peritoneal Neoplasms; Pseudomyxoma Peritonei
PubMed: 35621679
DOI: 10.3390/curroncol29050289 -
Cancer Management and Research 2021Excessive mucus secretion is the most prominent feature of pseudomyxoma peritonei (PMP), which often leads to significant increase in abdominal circumference,... (Review)
Review
Excessive mucus secretion is the most prominent feature of pseudomyxoma peritonei (PMP), which often leads to significant increase in abdominal circumference, intractable abdominal pain, progressive intestinal obstruction, abdominal organ adhesions, and cachexia. Excessive mucus secretion is also the main cause of death. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is the recommended treatment for PMP. However, recurrence is frequently observed even after CRS and HIPEC, presenting similar clinical manifestations. Mucin 2 (MUC2) is the main type of mucin in PMP and plays a key role in the progressive sclerosis of mucus. To comprehensively demonstrate the biosynthetic process and molecular features of MUC2 and to provide new directions for the development of PMP mucolytic strategies, this review systematically summarizes the molecular biology of MUC2, including gene structure, transcription, translation, post-translational modification, tertiary structure, and factors regulating mucus viscoelasticity. The results show that MUC2 is a highly glycosylated protein, with glycan accounts for 80% to 90% of the dry weight. The assembly pattern of MUC2 is highly complicated, presenting a bead-like filament. Salt concentration, pH, mucin concentration and trefoil factor family may contribute to the increase in mucus viscoelasticity and sclerosis, which could be used to develop drugs to soften or even dissolve mucus in the future.
PubMed: 34703312
DOI: 10.2147/CMAR.S324982 -
Indian Journal of Pathology &... 2022Low-grade appendiceal mucinous neoplasms (LAMN) of the appendix have bland cytological features and well-differentiated morphology. Despite this, they may cause a...
BACKGROUND
Low-grade appendiceal mucinous neoplasms (LAMN) of the appendix have bland cytological features and well-differentiated morphology. Despite this, they may cause a pseudomyxoma peritonei (PMP) disease characterized by mucinous deposits in the peritoneal cavity and may exhibit malignant behavior.
AIMS AND OBJECTIVES
In this study, we evaluated the clinical course and histopathological findings of LAMN. The rate of progression to PMP, factors affecting its development, and the clinical course of cases with PMP were investigated.
MATERIALS AND METHODS
Twelve thousand and forty-seven cases who underwent appendectomy were reviewed, and 71 mucinous lesions cases whose slides are in our archive were included in the study. Histopathological findings were re-evaluated. Morphological findings that guide the differential diagnosis, the clinical course of the patients, and factors affecting PMP development were determined.
RESULTS
The cases were divided into group 1 non-neoplastic (9.9%), group 2 benign (18.3%), group 3 LAMN (60.6), and group 4 malignant neoplasms (11.3%). Age, gender, appendix diameter, gross appearance, epithelial characteristics, and presence of microcalcification were significantly different between the patient groups. The presence of mucin in the ileocecal region was found to be significant in the development of PMP. It was observed that the additional procedure performed after the appendectomy did not prevent a recurrence.
CONCLUSION
LAMNs are lesions with characteristic findings and different behaviors. The only method to distinguish from the lesions included in the differential diagnosis is to interpret the histopathological findings correctly. Additional operations after appendectomy do not contribute to preventing recurrence.
Topics: Appendiceal Neoplasms; Diagnosis, Differential; Humans; Neoplasms, Glandular and Epithelial; Peritoneal Neoplasms; Prognosis; Pseudomyxoma Peritonei
PubMed: 35900483
DOI: 10.4103/ijpm.ijpm_827_21 -
Cancers Apr 2024Pseudomyxoma peritonei (PMP) is a rare disease characterized by extensive peritoneal implantation and mass secretion of mucus after primary mucinous tumors of the... (Review)
Review
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.
PubMed: 38611084
DOI: 10.3390/cancers16071406 -
Journal of Gastrointestinal Oncology Apr 2021Pathology is central to the management of peritoneal surface malignancy. This article highlights some recent advances that have had an impact on patient management or... (Review)
Review
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 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.
PubMed: 33968439
DOI: 10.21037/jgo-2020-01 -
Journal of Cancer Research and Clinical... Sep 2020Pseudomyxoma peritonei (PMP) is a rare clinical malignancy syndrome characterized by the uncontrollable accumulation of copious mucinous ascites in the peritoneal... (Review)
Review
PURPOSE
Pseudomyxoma peritonei (PMP) is a rare clinical malignancy syndrome characterized by the uncontrollable accumulation of copious mucinous ascites in the peritoneal cavity, resulting in "jelly belly". The mechanism of tumor progression and mucin hypersecretion remains largely unknown, but GNAS mutation is a promising contributor. This review is to systemically summarize the biological background and variant features of GNAS, as well as the impacts of GNAS mutations on mucin expression, tumor cell proliferation, clinical-pathological characteristics, and prognosis of PMP.
METHODS
NCBI PubMed database (in English) and WAN FANG DATA (in Chinese) were used for literature search. And NCBI Gene and Protein databases, Ensembl Genome Browser, COSMIC, UniProt, and RCSB PDB database were used for gene and protein review.
RESULTS
GNAS encodes guanine nucleotide-binding protein α subunit (Gsα). The mutation sites of GNAS mutation in PMP are relatively stable, usually at Chr20: 57,484,420 (base pair: C-G) and Chr20: 57,484,421 (base pair: G-C). Typical GNAS mutation results in the reduction of GTP enzyme activity in Gsα, causing failure to hydrolyze GTP and release phosphoric acid, and eventually the continuous binding of GTP to Gsα. The activated Gsα could thus continuously promote mucin secretion through stimulating the cAMP-PKA signaling pathway, which is a possible mechanism leading to elevated mucin secretion in PMP.
CONCLUSION
GNAS mutation is one of the most important molecular biological features in PMP, with major functions to promote mucin hypersecretion.
Topics: Biomarkers, Tumor; Cell Proliferation; Chromogranins; GTP-Binding Protein alpha Subunits, Gs; Humans; Mucins; Mutation; Peritoneal Neoplasms; Prognosis; Pseudomyxoma Peritonei; Signal Transduction
PubMed: 32700107
DOI: 10.1007/s00432-020-03321-8 -
Journal of Cancer Research and... Jan 2024Pseudomyxoma peritonei (PMP) is an unusual clinical condition typically presenting with widespread mucinous neoplastic lesions within the peritoneum resulting in gelatin...
BACKGROUND
Pseudomyxoma peritonei (PMP) is an unusual clinical condition typically presenting with widespread mucinous neoplastic lesions within the peritoneum resulting in gelatin material-rich ascites. It was first described by Werth in 1884. Ever since, its clinical presentation, definition, site of origin, and prognosis have been a subject of debate. However, many histopathologic, immunohistochemical, and genetic studies have attempted to locate the primary lesion in the appendix in both genders.
OBJECTIVES
To analyze the histological origin and survival outcomes of pseudomyxoma peritonei in patients treated at a regional cancer center.
MATERIALS AND METHODS
Fifteen cases of PMP were diagnosed during the five-year study period. The demographic and clinicopathological details were retrieved; the slides were reviewed and histological parameters reassessed. Descriptive statistics were used to express proportions. Continuous variables were recorded as mean (SD) or median (IQR). Kaplan-Meier (KM) curve was used to estimate overall survival.
RESULTS
Mean age for PMP was found to be 47.5 years for low grade Mucinous Carcinoma Peritonei (MCP), 54.2 years for high grade MCP, and 58 years for high grade MCP with signet ring cells. Most common overall presentation was abdominal distension in 53.3% (8/15) of cases, followed by acute appendicitis in 20% (3/15) cases. PMP was detected synchronous with the primary tumor in 9/15 cases (60%). Primary lesion in the appendix was grossly identified in 7/15 cases, while it was not explored in the remaining eight cases. Yet, by combined clinical, radiological, histopathological, and immunohistochemical analysis, we identified that most of the cases (14/15) had an appendiceal origin (93.3%). The overall survival for 12 months was 50% and for 18 months was 37%.
CONCLUSION
The surgeon and radiologist may well bear in mind the most common possibility of an appendiceal origin for PMP and resect the appendix, irrespective of the presence of a grossly or radiologically detectable lesions. We emphasize that immunohistochemistry helped to detect the site of origin even when the primary was occult.
PubMed: 38261429
DOI: 10.4103/jcrt.jcrt_191_23 -
World Journal of Gastrointestinal... May 2024We recently read with great interest a study by Zhang in the W. In our practice, we focus specifically on examining appendiceal mucinous neoplasms (AMNs) with...
We recently read with great interest a study by Zhang in the W. In our practice, we focus specifically on examining appendiceal mucinous neoplasms (AMNs) with endoscopic ultrasound (EUS) using different scopes. AMNs are rare neoplastic lesions characterized by an accumulation of mucin inside a cystic dilatation of the appendix. Clinically, they can present as nonspecific acute appendicitis. AMNs can turn into a life-threatening condition, termed pseudomyxoma peritonei, in which the ruptured appendix causes accumulation of mucin in the abdomen. Therefore, accurate and rapid diagnosis of AMN is essential. EUS is able to confirm and stage AMNs; although, EUS examination was once limited to the rectal and anal regions due to the conventional oblique-view scopes. With the emergence of new forward-view linear echoendoscopes and instruments like EUS miniprobes and overtubes, the scope of examination is changing. Herein, we discuss the feasibility of using the curved linear array echoendoscopes to examine cecal and appendiceal orifice lesions.
PubMed: 38813577
DOI: 10.4253/wjge.v16.i5.232 -
World Journal of Gastrointestinal... Sep 2019Pseudomyxoma peritonei (PMP) is a disease surrounded by misunderstanding and controversies. Knowledge about the etymology of pseudomyxoma is useful to remove the... (Review)
Review
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.
PubMed: 31572561
DOI: 10.4240/wjgs.v11.i9.358