Pseudomyxoma peritonei (PMP) is a type of tumor characterized by the progressive dissemination of jelly-like ascites and mucinous tumor in the peritoneum. PMP is a rare disease with an approximate annual occurrence of 0.5 to 1 cases in every 100,000 people.
The term pseudomyxoma peritonei was first coined by Werth in 1884. Frankel was the first person to represent the case as related to the appendix sac in 1901. Normally, PMP is acquired from different types of unknown signs and symptoms, which include swelling, abdominal pain, or blockade in the bowel movements.
Research Based on the Nature of PMP
In September 2002, UCLA School of Medicine, USA, published an article analyzing the causes of pseudomyxoma peritonei. In this study the author inspected the special mucin cDNA and similar antibodies to determine a typical marker for the PMP.
Finally, it was found that the genes MUC2 and MUC5AC have the chemical property of having a jelly form that exhibits PMP. Among the two types of mucin, MUC2 expression is more familiar, because it contains the average cell ratio of mucin at 10:1.
On October 22, 2008, seven authors came together to analyze the relation of microbial agents with the progression of PMP. In this study, an experiment was conducted using ultra-structural immunohistochemical technique with a sample tissue taken from a PMCA patient.
Testing showed the presence of bacteria expressed in PMP. It was also found that the malignant stage of PMP occurs due to the presence of an increased amount of bacterial density and gene MUC2. Thus, it was confirmed that bacteria play an important role in developing PMP.
A research was published titled “Molecular profiles of high-grade and low-grade pseudomyxoma peritonei” in October 2015. In this study was analyzed 18 PMP tumors consisting of 10 DPAMs and 8 PMCAs. After examining the extracted DNAs from the tumors, a total number of 35 somatic mutations in 10 genes were detected.
Drawing the conclusion, the researchers suggested that the common hereditary characteristic of PMP is KRAS, and/or GNAS mutations, in TP53, or genes which are related to PI3K-AKT tract that may cause malignant transformation to PMP. This identification may be widely used in knowing the features of tumors and help to develop the therapies.
Research on “Development of Treatment”
In May 1991, eight authors gathered to research the possible treatments for cure of PMP completely. They concluded that the blockade caused by intestinal compression is only relieved by a treatment known as surgical debulking.
This is followed by secondary treatment such as chemotherapy, immunotherapy, and radiotherapy, which produces various responses. Thus, till date there is no available suitable secondary treatment for cure of PMP.
Three researchers namely, Arijit Mukherjee, Shubhayu Banerjee, and Brendan J Moran conducted a study to find the possible treatment for cure of PMP during 2004. Here, the authors found that surgery combined with intraperitoneal chemotherapy gives a good feeling to the patient. So they concluded that complete removal of tumor is possible.
The study titled “Cytoreductive surgery and perioperative intraperitoneal chemotherapy for pseudomyxoma peritonei from appendiceal mucinous neoplasms” was researched by six authors for providing long-term survival for the PMP affected patient. The objective of this study was to investigate the treatment that is related to prognostic molecular markers in patients who have taken CRS with PIC surgery for PMP.
In November 2008, there was a case study undertaken on a 55-year old man suffering from PMP, determined by CT scan. The study explained that he could take 10 cycles of general chemotherapy with FOLFOX4 regimen after the operation. It showed excellent response for 21 months. This study brought up the new possibility of chemotherapy treatment for this rare disease.
In June 2013, a study was conducted regarding the development of antibiotics for killing the bacteria present in the mucin. The investigation processed by giving an antibiotic to 14 patients with either DPMA or PMCA. The results obtained showed that the PMCA patients receiving antibiotics have lesser bacterial density, but this is not so in DPMA patients. Cell membrane and catenin were increased in both the categories. So the researchers suggested that the antibiotic provides better protection across the cell separation and cellular dispersion. Yet, better discovery was needed.
A study conducted in 2017, which inspected 41 patients of an average age of 65 years, found that patients who had already undergone appendectomy may not need a reoperation, but a continuous follow-up with CT scan is enough.
The study was based on the records of patients who had the primary surgery and identified with LAMN, mostly determined by the histology results collected during the period from 2007 to 2013. The diagnosis of LAMN with CT scan every six months for continuously two years till 2015 was done.
Reviewed by Afsaneh Khetrapal BSc (Hons)