Peritoneal mesothelioma is a cancer affecting the abdominal lining, or peritoneum, and is sometimes referred to as abdominal mesothelioma. This membrane supports and covers the organs of the abdomen. Malignant peritoneal mesothelioma is an extremely rare condition; only 100 to 500 cases are diagnosed in the US each year, making up less than 20% of all mesothelioma cases.
The peritoneum is made of two parts, the visceral and parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. The parietal peritoneum covers the abdominal cavity. Cells in these linings secrete a fluid which allows organs to move against one another. The cells of the mesothelium are designed to create fluid, but the cancer causes them to overproduce, creating a build up of excess fluid in the abdominal cavity. Because pleural mesothelioma is more common and often spreads to the peritoneal cavity, it is important to determine if pleural mesothelioma is the primary cancer.
Treatment of Peritoneal Mesothelioma
In the February 2008 edition of the American Journal of Clinical Oncology, researchers from Columbia University reported that combined resection, intraperitoneal chemotherapy, and whole abdominal radiation therapy and found it to be an effective treatment for malignant peritoneal mesothelioma.
The latency period for abdominal mesothelioma appears to be 20-30 years, which is shorter than the time it takes to develop pleural mesothelioma in the lungs and it is much less common, making up less than 20% of all cases.
The Columbia University study involved 27 patients with malignant peritoneal mesothelioma and followed a regimen involving several steps:
- Surgical debulking followed by four intraperitoneal courses of cisplatin alternated with four intraperitoneal courses of doxorubicin
- Four doses of intraperitoneal gamma interferon
- Laparotomy with resection of residual disease
- Intraoperative hyperthermic administration of intraperitoneal mitomycin
- Cisplatin followed by whole abdominal radiation therapy.
The multimodality of therapy proved effective, showing a median survival of 70 months and a three-year survival of 67%. It is interesting to note that seven patients in the study went a full 17 months before seeing any evidence of the disease.