The peritoneum is the lining within the abdominal cavity and covers the intra-abdominal organs. It has several components including the outer (parietal) and inner (visceral) layers as well as the greater and lesser omentum.
The peritoneum supports the structure and metabolism of the intra-abdominal organs by providing an important source of blood and lymph circulation. The peritoneum therefore has a significant immunological role in localizing and attacking certain infections.
As the peritoneum is a relatively vascular and lymphoid structure, it can be a potential site of metastases from numerous malignancies, which leads to the diagnosis of PC.
There are several proposed mechanisms of how patients can develop PC. There can be direct extension of the intra-abdominal malignancy into the peritoneum or direct seeding of the peritoneum following tumor rupture.1
The peritoneum can also be seeded during surgery, especially when the abdomen is exposed to the contents of the lymph nodes or blood vessels during surgical exploration.
The clinical data are somewhat variable, however this direct seeding during potentially curative surgeries has been reported to be between 3% and 28%.1
It may be extremely difficult to ascertain when the peritoneum is seeded with malignant cells, as there may be a minute amount of cells that remain relatively undetectable by conventional means. PC has been reported in up to 40% of patients with colorectal cancer (CRC) at any time point within their clinical course.2
Treatment of PC can vary based on the site of the primary malignancy. Most of the recent data and clinical trials have focused on PC associated with CRC.
Older, more traditional treatments in patients with PC secondary to CRC include removal of the omentum, systemic and/or palliative chemotherapy, and palliative surgery. Newer treatment options include cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), and intraperitoneal chemotherapy.