Prognostic significance of single isolated cells with decreased E-cadherin expression in pseudomyxoma peritonei

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.

Role of Epithelial-Mesenchymal Plasticity in Pseudomyxoma Peritonei: Implications for Locoregional Treatments

The mechanisms by which neoplastic cells disseminate from the primary tumor to metastatic sites, so-called metastatic organotropism, remain poorly understood. Epithelial-mesenchymal transition (EMT) plays a role in cancer development and progression by converting static epithelial cells into the migratory and microenvironment-interacting mesenchymal cells, and by the modulation of chemoresistance and stemness of tumor cells. Several findings highlight that pathways involved in EMT and its reverse process (mesenchymal-epithelial transition, MET), now collectively called epithelial-mesenchymal plasticity (EMP), play a role in peritoneal metastases. So far, the relevance of factors linked to EMP in a unique peritoneal malignancy such as pseudomyxoma peritonei (PMP) has not been fully elucidated. In this review, we focus on the role of epithelial-mesenchymal dynamics in the metastatic process involving mucinous neoplastic dissemination in the peritoneum. In particular, we discuss the role of expression profiles and phenotypic transitions found in PMP in light of the recent concept of EMP. A better understanding of EMP-associated mechanisms driving peritoneal metastasis will help to provide a more targeted approach for PMP patients selected for locoregional interventions involving cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Outcome and surgical strategy in critical sites in cases of psuedomyxoma peritonei

BACKGROUND

For a long time peritoneal neoplasms were considered beyond surgical intervention and beyond cure, till the concept of cytoreductive surgery (CRS) and adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC) was introduced. However this surgical intervention is technically demanding and associated with considerable postoperative morbidity.

OBJECTIVE

To describe the surgical strategy in resection of critical sites loaded by heavy tumor deposits and to evaluate short and long term results of CRS and HIPEC, in a cohort of Egyptian patients with pseudomyxoma peritonei (PMP) from appendiceal origin.

PATIENTS AND METHODS

21 patients with PMP, age ranged from 40 to 63years, 12 males and 9 females. All were recruited from the department of surgery at the National Cancer Institute (NCI), Cairo University over the period from February 2011 to February 2016. They were subjected to CRS and HIPEC with mitomycin-C.

RESULTS

The median peritoneal carcinoma index (PCI) was 22 (range: 10-39). Optimal cytoreduction (CCR-0/1) was achieved in 19 patients (90.4%) of whom 17 patients (80.9%) had a complete cytoreduction (CCR-0). The median follow up period was 51.5months (range: 0.07-82.3months). The cumulative overall survival was 85.7% while the cumulative disease free survival was 76.9%.

CONCLUSION

To the best of our knowledge, this is the first study reporting five years postoperative outcome of CRS and HIPEC in Egyptian patients with PMP from appendiceal origin. Our results support that although technically demanding this treatment modality is safe and associated with favorable outcome.