Primary peritoneal cancers, or PPCs, are cancers that primarily present in the peritoneal tissues or the individual organs of the peritoneum before invading or metastisizing elsewhere. The peritoneal cavity is the largest potential space in the human body, allowing for the free movement of cells and fluid which results in a higher than normal diffusion rate that aids the spread of cancer cells. Two of the main types of PPCs are malignant mesothelioma and a unique type of ovarian cancer.
The Peritoneum and the Peritoneal Cavity
The peritoneum is a smooth serous membrane consisting of a thin layer of mesothelium cells that secrete serous fluid. The peritoneum lines the abdominal cavity and covers many of the abdominal organs. Its purpose is to support the organs and keep them lubricated so that they can move freely without friction.
The peritoneum consists of the parietal peritoneum, which lines the abdominal walls and the visceral peritoneum, which covers the outer layer of most abdominal organs. The space between these two layers is called the peritoneal cavity. Organs within the peritoneum include the pelvis, stomach, spleen, liver, gallbladder and the intestines. In women, it also includes the uterus, the fallopian tubes and the ovaries.
Malignant Mesothelioma
Malignant mesothelioma is a rare but increasing aggressive type of cancer that is found within the lining of the chest or abdomen. Twenty to 30% of mesotheliomas arise from the peritoneum. Malignant peritoneal mesothelioma associated with asbestos exposure is as high as 83% and peritoneal mesothelioma is the second most common form observed. (Emedicine.com, accessed Apr. 11, 2010)
According to Asbestos.com, of the 2,000-3,000 new cases of malignant mesothelioma diagnosed annually, 10-20% of them are peritoneal. (Accessed Apr. 11, 2010). This type of cancer develops when asbestos fibers travel between the peritoneal layers and divide and multiply into tumors. The large peritoneal cavity promotes free movement and so cancer cells can spread rapidly and invade other organs, also known as mestastisizing. There is no cure at present for peritoneal mesothelioma.
Ovarian Cancer not in the Ovaries
Another primary peritoneal cancer is extraovarian primary peritoneal cancer (EOPPC). It is not typical ovarian cancer because it barely touches the ovaries and can occur several years after a bilateral oophorectomy (the removal of both ovaries).
This cancer does imitate ovarian cancer in presentation, appearance, how it spreads and prognosis. This type of cancer is sometimes referred to as “ovarian cancer not in the ovaries.” Healthresource.com (Accessed Apr. 11, 2010). About 7-10% of ovarian cancer diagnoses are actually EOPPCs, however ovarian cancer can also spread to the peritoneum.
Primary Peritoneal Cancers
The causes of PPCs is unknown. Outside of asbestos exposure, PPC is more common in women than men. Symptoms may include:
- nausea or a feeling of indigestion and bloating
- loss of appetite but unexpected weight gain
- changes in bowel and bladder habits
- lower abdominal pain
- swollen stomach from fluid retention (ascites)
PPC may not have the exposure of other forms of cancer because of its rarity. Its aggressive nature and few warning signs (until the later stages), makes this cancer a force to be reckoned with. According to the Primary Peritoneal Cancer Foundation, PPC affects between 2,000-10,000 women every year and because it is indisguishable from ovarian cancer and may develop years after the removal of tubes and ovaries, education and awareness of PPC needs to be stepped up.
Elizabeth Batt - Elizabeth Batt is a former large animal nurse, certified NREMT, lover of equines and conservationist.
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