Peritoneal Cancer: Symptoms, Causes & Treatment

Peritoneal cancer is a rare malignant tumor that develops in the tissue that lines the inside of the abdomen and covers the abdominal organs. It can cause symptoms such as abdominal pain, nausea, bloating, and unexplained weight loss.

This type of cancer can start in the peritoneum itself and is more common in postmenopausal women. It can also happen when other cancers spread to the peritoneum, such as ovarian, gastrointestinal, or mediastinal cancer.

Treatment for peritoneal cancer is guided by an oncologist. It may include surgery to remove tumor deposits, chemotherapy, radiation therapy, immunotherapy, or targeted therapy.

Main symptoms

The main symptoms of peritoneal cancer are:

• Abdominal bloating

• Nausea or indigestion

• Abdominal or back pain

• Constipation or diarrhea

• Fatigue and general malaise

• Loss of appetite

• Unexplained weight loss

Symptoms of peritoneal cancer vary depending on where the tumor is located and how extensive it is, meaning the number of tumor deposits in the peritoneum.

In addition, if the disease is found at a more advanced stage, the person may develop ascites, which is a buildup of fluid inside the abdominal cavity.

This fluid can press on the lungs and cause shortness of breath or difficulty breathing.

Confirming a diagnosis

A diagnosis of peritoneal cancer may be suspected by a primary care provider, gastroenterologist, or gynecologist based on symptoms, health history, a physical exam, lab tests, and imaging tests.

The doctor may order an abdominal ultrasound, CT scan, MRI, PET scan, urine tests, blood tests, and tumor marker tests.

In addition, the doctor may perform a laparoscopy or laparotomy, which are surgical procedures that allow the inside of the peritoneal cavity to be seen.

After the diagnosis is confirmed, the person is referred to an oncologist to start treatment.

Possible causes

The exact cause of peritoneal cancer is not fully known. However, it is thought to develop when DNA mutations cause cells to grow and multiply abnormally.

According to the National Cancer Institute, inherited BRCA1 or BRCA2 gene mutations are associated with a higher risk of primary peritoneal cancer, as well as ovarian and fallopian tube cancer.

Other factors that may increase the risk of peritoneal cancer include:

• Family history of breast cancer

• Hormone replacement therapy (HRT) during menopause

• Endometriosis

• Obesity

• Exposure to asbestos

In addition, peritoneal cancer can be caused by metastasis from other types of cancer, such as stomach, ovarian, uterine, breast, lung, intestinal, appendix, or gallbladder cancer.

Rare tumors or tumor-like conditions, such as disseminated peritoneal leiomyomatosis, leiomyosarcoma, and desmoplastic small round cell tumor, can also affect the peritoneum.

Main types

The main types of peritoneal cancer are:

1. Primary peritoneal cancer

Primary peritoneal cancer starts in the peritoneum itself. It is a rare type of tumor that has similarities to epithelial ovarian cancer and can cause symptoms similar to ovarian cancer.

This type of tumor mainly affects postmenopausal women and is rare in men.

The peritoneum is a membrane that lines the abdominal wall and the organs in the abdomen, such as the ovaries, liver, spleen, stomach, intestines, and rectum, helping to protect these organs.

2. Secondary peritoneal cancer

Secondary peritoneal cancer happens when other cancers spread to the peritoneum. It can occur with cancers that affect abdominal organs, such as the stomach, intestines, ovaries, bladder, or appendix.

Treatment options

Treatment for peritoneal cancer should be guided by an oncologist and varies depending on the stage of the tumor, as well as its size and location. According to the National Cancer Institute, ovarian epithelial, fallopian tube, and primary peritoneal cancers are treated in similar ways.

The main treatments for peritoneal cancer include:

1. Surgery

Surgery for peritoneal cancer, called cytoreductive surgery, is performed by a surgical oncologist to remove all visible tumor deposits from the layers of the peritoneum.

In addition, if the doctor finds tumors in organs or tissues within the abdominal cavity, these may also be removed.

2. Intraperitoneal chemotherapy

Intraperitoneal chemotherapy is given directly into the peritoneal cavity through a catheter placed under the skin during surgery.

This type of chemotherapy lasts from 30 minutes to 3 hours. After it is finished, the person is usually advised to lie down and change position every 15 minutes so the chemotherapy drug can reach all organs in the abdominal cavity.

Examples of chemotherapy drugs that may be given intraperitoneally include cisplatin, paclitaxel, or doxorubicin.

3. Hyperthermic chemotherapy

Hyperthermic chemotherapy is also given directly into the abdominal cavity. However, it is done during surgery to help destroy any cancer cells that may remain.

In this type of chemotherapy, the medication is heated to a temperature between 105.8°F and 109.4°F (41°C to 43°C) to help improve its effect on tumor cells.

Examples of chemotherapy drugs that may be used in hyperthermic chemotherapy include mitomycin C, doxorubicin, cisplatin, or oxaliplatin.

4. Intravenous chemotherapy

Intravenous chemotherapy is given through a vein. It may be recommended before surgery to help shrink the tumor and make it easier to remove.

This type of chemotherapy is not usually used as standard treatment for peritoneal cancer because tumor cells may be resistant to several commonly used chemotherapy drugs.

5. Radiation therapy

Radiation therapy uses radiation to destroy cells that cause peritoneal cancer. It is applied with a machine that sends radiation directly to the area where the tumor is located.

This treatment is rarely used. However, it may be recommended before surgery to reduce the size of the tumor in the peritoneum, or after surgery to help destroy remaining cancer cells.

6. Targeted therapy

Targeted therapy for peritoneal cancer may be recommended for tumors that have spread to the peritoneum.

These medications help target cancer cells more specifically, causing fewer effects on normal cells in the body.

Examples of targeted therapy drugs that may be used include olaparib, rucaparib, or niraparib, especially for ovarian cancer.

7. Immunotherapy

Like targeted therapy, immunotherapy may be used to treat cancer that has spread to the peritoneum and formed metastases.

This type of treatment increases the immune system’s response against cancer cells, which may help shrink the tumor or slow its growth.

Is peritoneal cancer curable?

Peritoneal cancer is very difficult to cure. The goal of treatment is usually to help the person live longer while improving quality of life and physical, mental, and social well-being.

In more severe cases, when peritoneal cancer is advanced and has spread to other organs, palliative care may be important to help relieve pain and significant discomfort.