Peritoneal cancer (peritoneal carcinomatosis) refers to the infestation of the lining of the abdominal organs (peritoneum) with malignant cells. In most cases, these are tumor cells.
In most cases, the tumor cells in peritoneal cancer are metastases of another tumor in the abdominal cavity. Very rarely, they originate from a tumor disease of the peritoneum itself.
Infestation and spread of the tumor cells can vary greatly and influence the prognosis and course of the disease. The involvement may be limited to a few nodes in certain areas of the peritoneum (limited peritoneal carcinomatosis).
This usually affects areas in the abdominal cavity where there is little movement of the intestines. The small intestine is one of the most mobile structures, while the large intestine is less mobile. Areas with low motility (ability to move actively) are located, for example, in the cecal area or in the Douglas space.
The prognosis of limited peritoneal carcinomatosis is better than that of diffuse peritoneal carcinomatosis . However, the latter is more common. Typically, larger tumor nodules are scattered throughout the peritoneum and on the surface of the adjacent organ structures (diffuse peritoneal carcinomatosis).
The peritoneum is a thin layer of skin that surrounds most of the organs in the abdominal cavity.
The abdominal cavity contains
The peritoneum produces a fluid, the abdominal fluid. This provides a lubricating layer between the organs and allows them to move easily between each other.
During digestion, for example, the intestinal loops move against each other to transport food. Abdominal fluid also forms in the event of liver damage and inflammation.
Nerves run through the peritoneum. Inflammation can therefore lead to severe pain. The abdominal muscles harden in order to protect the abdomen. This reaction is called defensive tension and is a warning sign from the body that something is wrong in the abdomen.
The peritoneum is a smooth skin that lines the inside of the abdomen @ sakurra /AdobeStock
The tumor can originate from the peritoneum itself (primary peritoneal carcinoma, peritoneal mesothelioma). In most cases, peritoneal cancer is the result of a malignant tumor of another organ in the abdominal cavity.
In this case, the malignant cells spread into and across the peritoneum. Doctors then speak of secondary peritoneal carcinoma because the malignant cells originate from other tissues.
However, secondary peritoneal carcinoma is always an expression of advanced tumor disease from the organ of origin. Gastric cancer and pancreatic cancer in particular are prone to peritoneal carcinomatosis, as are ovarian tumors.
Abdominal fluid promotes the spread of tumors between the individual organs. The tumor cells can spread very easily through the lubricating layer.
Almost every type of tumor that occurs in any way in the abdominal cavity will eventually invade the peritoneum and form metastases there. However, this is already an expression of advanced tumor growth and usually indicates poor prospects of recovery.
Pseudomyxoma peritonei is a rare tumor entity that can also lead to peritoneal cancer. This is a tumor that produces large quantities of mucous masses. The tumor cells migrate from the appendix into the peritoneum.
Even if it is a benign tumor, the course is comparable to that of a slowly growing malignant tumor. At an advanced stage, the entire peritoneum is enriched with gelatinous tissue and tumor masses.
As peritoneal cancer is usually caused by an advanced tumor of an abdominal organ, symptoms depend on the organ affected.
Typical symptoms of stomach cancer are
- Nausea
- loss of appetite and
- stomach pain
- Complaints with tumors of the small intestine tend to be
- Diarrhea
- constipation
- Intestinal obstruction
Infestation of the peritoneum tends to lead to atypical symptoms, which are less likely to prompt a visit to the doctor. They can initially be treated with home remedies.
The increasing expansion of the tumor cells leads to the displacement of adjacent abdominal organs with subsequent functional disorders.
This leads to
- Urinary retention due to the narrowing of the ureters
- Restrictions in bowel function (subileus) up to and including
- complete intestinal obstructions (subileus and ileus) as well as the
- formation of abdominal fluid(ascites)
Impairment of the gastrointestinal tract is often accompanied by the following symptoms:
- Nausea
- a feeling of fullness
- loss of appetite and
- nausea
Doctors often only discoverperitoneal cancer during surgery on the primary tumor. As further examinations (computer tomography (CT) or magnetic resonance imaging (MRI) are carried out, peritoneal cancer is often suspected in advance.
However, a CT or MRI scan only provides reliable information when the tumor in the abdominal cavity is already advanced.
A laparoscopy is considered the safest method for detecting peritoneal cancer. During this examination, the doctor inserts a special endoscope into the abdominal cavity through a small incision in the skin.
This is equipped with a light source and a camera. This allows doctors to view theinside of the abdominal cavity and the abdominal organs via a monitor.
If there are any abnormalities, doctors can and should also take tissue samples at the same time. They then send this sample for histological examination, which confirms or excludes the suspected diagnosis.
Laparoscopy is suitable for diagnosing peritoneal cancer @ Iryna /AdobeStock
If only a small part of the peritoneum is affected by tumor cells, doctors can ideally remove this part completely.
As doctors often only discover peritoneal cancer at a late stage, it is considered difficult to treat and is often no longer curable.
If a cure is no longer possible, doctors can only initiate palliative measures. These are intended to improve the patient's quality of life without fighting the actual tumor disease.
Life expectancy is significantly reduced in such cases. The main aim of all therapeutic measures is to improve the remaining time of life.
Palliative measures include
- Pain therapy
- nutritional therapy
- chemotherapy
- Surgical tumor reduction
- Creation of an artificial bowel outlet
Pain therapy
Pain therapy is generally possible with tablets and/or pain patches and serves to improve the quality of life. In some cases, the pain can only be controlled with infusions. In such cases, pain catheters are used.
Special catheters (so-called port catheters) are inserted under the skin. This means that pain therapy can also be administered outside the hospital. This allows patients to spend the rest of their lives at home with their relatives.
A pain catheter is a thin plastic tube through which the patient receives pain medication @ Gecko Studio /AdobeStock
Nutritional therapy
In some cases, patients with incurable cancer are no longer able to consume sufficient food and fluids. It is not uncommon for them to have a lack of appetite, which is a typical sign of malignant diseases.
On the other hand, tumor diseases are also associated with an increased energy requirement, which often leads to deficiency symptoms and weight loss.
Nutritional infusion therapy can help here and can also be administered via a port catheter. The patient also receives important minerals and vitamins.
Chemotherapy
Chemotherapy can be curative or palliative. Curative means that a cure is possible in principle.
The aim of palliative therapy is to improve quality of life by reducing tumor size or tumor growth.
As all chemotherapy has side effects, doctors should carefully consider whether to carry out palliative chemotherapy.
Ideally, palliative chemotherapy can prolong life expectancy. However, the side effects often lead to a deterioration in quality of life.
Surgical tumor reduction
Removal of the tumor tissue from the peritoneum consists of
- Removal of the primary tumor
In many cases, removal of the directly connected organs (spleen, gall bladder, diaphragm and parts of the intestine)
The patient must be aware of this before the operation and give their written consent. Curative chemotherapy may still be necessary afterwards if the tumor has not been completely removed with certainty.
This is because doctors can remove all visible tumors during the operation. However, individual invisible tumor cells may remain.
- Creation of an artificial bowel outlet
Sometimes the patient is also given an artificial anus. This may be necessary temporarily to relieve the healthy bowel.
This is particularly the case if doctors have removed parts of the bowel and stitched the remaining ends together.
In this case, the upstream insertion of an artificial bowel outlet can relieve the strain on the bowel suture. This in turn reduces the risk of the suture rupturing.
