Peritoneal Mesothelioma: An Uncommon Cancer of the Abdominal Lining

Fig 1. The peritoneum is the membrane lining the abdominal cavity and covering the abdominal organs.

Peritoneal mesothelioma (PM) is a uncommon and aggressive cancer that affects the peritoneum, the membrane which lines the abdominal cavity and covers the abdominal organs. Its symptoms are often non-specific, leading to delayed diagnosis. However, recent advances in multimodality treatment, particularly cytoreductive surgery combined with heated chemotherapy, have significantly improved the prognosis for selected patients.

Causes and risk factors

The only suspected cause of peritoneal mesothelioma is asbestos exposure. This is because pleural mesothelioma, which affects the lining of the lungs has been strongly linked to asbestos. However, the majority of PM cases do not have a documented history of exposure.

Other potential risk factors include genetic mutations, prior radiation therapy, and chronic inflammation of the abdomen.

Signs and symptoms

The early symptoms of peritoneal mesothelioma are non-specific and vague, resulting in delays in diagnosis. As the disease often remains confined to the abdomen, patients gradually develop symptoms of abdominal distension and bloatedness.

Common symptoms include:

• Abdominal pain and swelling.

• Nausea and vomiting.

• Unexplained weight loss.

• Loss of appetite or feeling full easily.

• Changes in bowel habits, such as constipation or diarrhoea.

  
  

Diagnosis

A diagnosis of PM is tricky and often requires proper evaluation by a specialist experienced treating the condition. Often it is overlooked as patients with PM have vague and non specific symptoms.

When suspected to have PM, patients usually have to undergo procedures that include:

• Imaging: A computed tomography (CT) scan of the chest, abdomen, and pelvis is the most common test. It can show signs such as peritoneal thickening, nodules, and ascites. An MRI or PET-CT may sometimes be used for more details.

  
  

• Biopsy: The best way to confirm the diagnosis of PM is through a biopsy. Often, a laparoscopic biopsy offers the higher diagnostic yield. Specialized staining of the tissue sample will be performed to distinguish PM from other cancers that can look similar under the microscope.

Treatment options

Treatment for peritoneal mesothelioma has evolved from primarily palliative care to a multimodality approach that can offer significant long-term survival for patients.

Key treatments include:

• Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC): This is the standard of care for operable disease.

  • CRS: Surgery is used to remove all visible tumours within the abdominal cavity.

  • HIPEC: Immediately after surgery, a heated, high-dose chemotherapy solution is circulated throughout the abdomen to kill any remaining microscopic tumour cells.

    
    

• Systemic therapy: For patients who are suitable for surgery, systemic therapy (drugs given orally or intravenously) can help slow the cancer's growth and manage symptoms. This can be a combination of chemotherapy and immunotherapy. If there is good response to the therapy, patients can be evaluated for the feasibility of CRS and HIPEC.

Prognosis and outlook

The prognosis for PM is highly dependent on factors such as the stage of the cancer, the tumor type, and the response to systemic treatment.

• Overall outlook: In the past, the median survival was less than a year without treatment. However, advances in therapy, especially with CRS and HIPEC, have dramatically improved outcomes.

• Impact of CRS-HIPEC: For patients suitable for and undergoing CRS-HIPEC treatment, the median survival has improved, with five-year survival rates ranging from 40% to over 60% in some cases.

• Tumour type: The epithelioid subtype, the most common type, is associated with a better prognosis than the sarcomatoid or mixed subtypes.

• Gender: Some studies have shown that women with peritoneal mesothelioma tend to have a better prognosis than men.

  
  

At Melissa Teo Surgery and The Surgical Oncology Clinic, our specialists have the experience in treating Peritoneal Mesothelioma. We believe that the current care and treatment strategies are improving the treatment of this rare condition, resulting in a growing number of patients achieving long-term survival and an good quality of life.

Please feel free to contact our clinic if you have any questions on Peritoneal Mesothelioma. 

References:

1. GHC Tan, M Cheung, J Chanyaputhipong et al. Ann Acad Med Singapore 2013;42:291-6 https://doi.org/10.47102/annals-acadmedsg.V42N6p291

2. Kim J, Bhagwandin S, Labow DM. Malignant peritoneal mesothelioma: a review. Ann Transl Med. 2017 Jun;5(11):236.