Peritoneal adenocarcinoma is a type of abdominal cancer that begins within the peritoneum lining — the membrane covering the inner wall of the abdominal cavity — and then spreads to other abdominal and pelvic organs. This cancer originates from epithelial tissue — or tissue forming membranes and linings in the body — and is characterized as epithelial cancer, or carcinoma. It is an extremely rare form of epithelial cancer, however, even though these cancers comprise about 85% of all cancerous malignancies.
Medical references to this disease as a specific type of carcinoma began to appear in the 1950s. These references generally identify peritoneal adenocarcinoma as occurring principally in women, chiefly women past childbearing age who have had their ovaries removed. The cancer has been found to have clinical features similar to carcinoma of the pelvic reproductive organs, such as ovarian cancer, despite an absence of the ovaries. Moreover, it has been generally concluded that the cancer arises from the lining of the pelvis or abdomen instead of the ovaries.
Peritoneal adenocarcinoma has been termed primary peritoneal carcinoma, or PPCa, and it is also known as extraovarian primary peritoneal carcinoma, or EOPPC, as well as primary peritoneal papillary serous adenocarcinoma. The cancer has also been felt to resemble peritoneal mesothelioma, however peritoneal mesothelioma has become more closely identified with a deadly type of cancer associated with asbestos, and EOPPC has not been linked with asbestos exposure.
The causes of peritoneal adenocarcinoma remain unclear. It is a recently recognized form of cancer, with unknown risk factors, and it is still being defined by medical professionals, some of whom believe that it may have been previously misdiagnosed as ovarian cancer. Others believe that it may be increasing. Cancer centers that track statistics on types and prevalence of cancer in the population currently estimate that EOPPC is showing up at a ratio of about 1:10 cases of ovarian cancer, and about 500 reports are on file that identify peritoneal adenocarcinoma as being the cancer type.
Symptoms of peritoneal adenocarcinoma can include those that are similar to many other abdominal disorders, such as pain or discomfort in the abdomen, nausea, or a feeling of fullness. It has also been found that about 85% of patients who were diagnosed with peritoneal adenocarcinoma had ascites, or an unusual amount of fluid in the abdominal area. In lab tests, many of the patients had a high level of a tumor indicator, called CA-125.
Peritoneal adenocarcinoma can rapidly develop into carcinomatosis. This means that it can widely metastasize, or spread throughout the body to regions such as the liver and the brain. Carcinomatosis is treated by an operation called a peritonectomy, which removes parts of the peritoneum, or stomach lining. This has been found to be helpful with regard to survival rates from this type of cancer.