Peritoneal metastases in breast cancer

Most often peritoneal metastases occur as a result of cancer in the abdominal cavity. However, they can also occur as a result of breast cancer. If metastases occur in breast cancer, the breast cancer is generally considered to be incurable.

Nevertheless, this is not the end of the medical measures, a doctor can still be there for the patient and alleviate symptoms. About 30% of women with breast cancer develop metastases because the cancer cells can spread throughout the body via the blood or lymph channels. In order to prevent metastases or to detect them at an early stage, patients suffering from cancer should have regular check-ups. In general, peritoneal metastases are not typical for breast cancer, but occur rather rarely. More frequent are bone, liver, brain and lung metastases.

Peritoneal metastases in ovarian cancer

Ovarian cancer is divided into four stages. FIGO I and II describe a cancer that affects either only the ovaries or the pelvis. Unfortunately, ovarian cancer is often diagnosed late, which is why ovarian cancer has sometimes already spread to the adjacent peritoneum.

The presence of peritoneal metastases thus classifies a tumour as FIGO III. Only in the further course of the disease does the cancer metastasise beyond the neighbouring body and metastases can also be found in the lungs or lymphatic system. In this advanced stage, surgical therapy includes the removal of the ovaries, fallopian tube, uterus and peritoneum.

If the peritoneal metastases have already spread to other abdominal organs, such as the liver or intestines, it may also be necessary to remove them. Chemotherapy is then started to fight the cancer cells in the blood. The survival time of patients with ovarian cancer varies depending on the original classification. Patients with peritoneal metastases can still have a good prognosis if it is possible to remove the tumour and metastases completely.

Peritoneal metastases in gastric cancer

In the case of extensive growth, which breaks through the stomach walls, a tumour of the stomach can also spread to the adjacent peritoneum and lead to peritoneal metastases. It can then infiltrate the lymph nodes, lymph channels and blood vessels. Common metastasis sites in gastric cancer are the peritoneum, liver, surrounding lymph nodes and lungs.

In the case of peritoneal metastases, there is no cure for stomach cancer. Nevertheless, it may be useful to perform surgery to relieve severe symptoms caused by the tumour and the metastases. An important part of the therapy is then chemotherapy, which can cause the cancer and metastases to regress or stagnate.

The therapy of peritoneal metastases proves to be extremely difficult. In general, these only occur in the late stages of cancer. Often metastases (metastases or filae) of the original tumour (primary tumour) are then found in other parts of the body, and the metastases are usually numerous and advanced in size.

In the case of a metastatic infection of the peritoneum, this often occurs over a large area. A recurrence of a tumour in the peritoneal cavity or peritoneum is also not unusual. In such cases, the tumour has often already developed resistance to the previously used chemotherapeutic agents, which makes therapy even more difficult.

In addition, the peritoneum is a region of the body with poor blood supply and chemotherapeutic drugs cannot easily reach metastases located there via the bloodstream. In summary, the therapy of peritoneal metastases is difficult because they are often limited in size and blurred and are pharmacologically difficult to reach via the bloodstream. If the patient and treating physician then decide, despite a moderate chance of success, not for a palliative therapy, but for one that aims at healing (curative approach), a complex, interdisciplinary intervention is usually necessary.

This consists of a surgical removal of the peritoneum (peritonealectomy) with subsequent irrigation of the abdominal cavity with chemotherapy. In order to increase the effectiveness of this intraoperative chemotherapy, it is routinely warmed up – thus promoting local blood circulation. If the irrigation is carried out with a fluid, the specialist speaks of hyperthermic intraperitoneal chemoperfusion (HIPEC). Alternatively, the drug can also be nebulized by a small pump directly in the abdominal cavity, allowing the chemotherapeutic agent to reach the most remote areas even better. This procedure is called Pressurized Intraperitoneal Aerosol Chermotherapy and is abbreviated to PIPAC.