Doctors stage peritoneal cancer depending on the size and position of the cancer, where it has spread from, and how fast it can spread. There are two stages of primary peritoneal cancer and five stages of secondary peritoneal cancer.
Peritoneal cancer is a type of cancer that develops in the epithelial cells that line the peritoneum, which is the inside of the abdominal wall. The peritoneum surrounds and protects the organs in the abdomen, such as the bladder, intestines, uterus, and ovaries.
This article looks at how staging works for peritoneal cancer and what the treatment and outlook are for each stage of peritoneal cancer. It also answers some frequently asked questions.
Primary peritoneal cancer (PPC) is a
Doctors diagnose stage 3 peritoneal cancer if the tumor developed inside the peritoneal cavity and has not spread to any other areas of the body.
Stage 3 is further divided into the following:
- Stage 3A: The cancer is in the pelvic organs and has reached nearby lymph nodes in the abdomen.
- Stage 3B: The tumor is 2 centimeters (cm) or smaller, and the cancer is in both the peritoneum outside the pelvis and the lymph nodes outside the peritoneum.
- Stage 3C: As with stage 3B, the cancer is in the peritoneum outside the pelvis and the lymph nodes outside the peritoneum. However, the tumor is larger than 2 cm.
Doctors will categorize PPC as stage 4 if the cancer has metastasized, or spread, to other areas of the body. Doctors further divide stage 4 PPC into the following:
- Stage 4A: There are cancer cells in fluid that has built up around the lungs.
- Stage 4B: The cancer has spread to other areas of the body, such as the liver, lungs, or distant lymph nodes.
Doctors diagnose secondary peritoneal cancer when a primary tumor — usually within the abdomen, from either the gastrointestinal tract, female reproductive organs, or genitourinary organs — spreads to the peritoneum.
This type of peritoneal cancer is
- Stage 0: There is a microscopic amount of cancer.
- Stage 1: There is a tumor smaller than 5 millimeters (mm) in only one area of the abdomen.
- Stage 2: There is a tumor smaller than 5 mm, but it has started to affect the entire abdomen.
- Stage 3: There are several tumors that are smaller than 2 cm but larger than 5 mm.
- Stage 4: There are several tumors present that are larger than 2 cm.
Doctors may diagnose and stage peritoneal cancer with a series of tests, which may
- pelvic exam
- medical history and physical exam
- blood tests
- CT scan
- PET scan
- MRI scan
Doctors will treat peritoneal cancer using a combination of surgery, targeted therapy, and chemotherapy.
Doctors will initially try to remove as much of the tumor as possible through surgery. They may also perform a hysterectomy and remove the ovaries, fallopian tubes, and uterus.
To determine how to treat the cancer after surgery, doctors will assess the grade of the tumor.
The cells of a low grade tumor appear almost normal. If a doctor has removed a low grade peritoneal tumor, the person may not require further treatment.
High grade tumors pose a higher risk of the cancer spreading further and growing faster. A doctor may decide to monitor the person and delay further treatment, or administer chemotherapy.
Doctors typically treat stage 2 peritoneal cancer with surgery first to debulk and stage the cancer while removing as much of the tumor as possible.
Once surgeons have removed as much of the cancer as possible, doctors will treat the patient with chemotherapy.
At stage 3, doctors will begin by performing surgery to debulk the cancer. They may also perform a hysterectomy. The surgeons will attempt to leave behind no tumor larger than 1 cm.
In some cases, surgery may involve the removal of parts of organs such as the intestine, liver, or bladder.
After surgery, doctors typically administer chemotherapy and the targeted drug bevacizumab (Avastin). Doctors will continue to monitor the person during and after treatment.
If a person is not healthy enough to undergo surgery, doctors may first treat them with chemotherapy, which they will follow with surgery and further cycles of chemotherapy.
Stage 4 peritoneal cancer is difficult to treat, as the cancer has spread to distant areas of the body, such as the lungs, bones, or liver.
Doctors typically begin with surgery to remove as much of the tumor as possible. They usually follow surgery with chemotherapy and, in some cases, the targeted drug bevacizumab (Avastin).
Doctors may opt to administer chemotherapy before surgery to try to shrink the tumor. They generally follow with surgery and further cycles of chemotherapy.
Doctors may treat the person with drugs, such as olaparib, rucaparib, and niraparib, to help stop the cancer from returning.
Doctors may also discuss limiting treatments to include only those that improve the person’s comfort but do not fight the cancer. This is called palliative care.
Primary peritoneal cancer has a median survival of 11–17 months, while the median survival of those with secondary peritoneal cancer differs depending on the stage.
The median survival for those with secondary peritoneal cancer at stages 0, 1, and 2 is 5–10 months. The median survival for peritoneal cancer stages 3 and 4 is 2.3 to 9 months.
The location of the primary tumor within the peritoneum may also affect survival rates:
- A tumor in the colorectal region has a median survival of 6.9 months.
- A tumor in the gastric area has a median survival of 6.5 months.
- A tumor in the pancreatic area has a median survival of 2.9 months.
The following are frequently asked questions about peritoneal cancer.
Is peritoneal cancer aggressive?
Yes, peritoneal cancer is aggressive. Doctors also often diagnose it in the later stages due to a lack of noticeable symptoms, which can lead to treatment being less effective.
Is it possible to survive peritoneal cancer?
A person can survive peritoneal cancer, although the median survival varies wildly and depends on the stage and grade of the cancer, the location of the tumor, the person’s age, and other factors.
What is the average life expectancy for peritoneal cancer?
The average life expectancy of a person with primary peritoneal cancer is
Peritoneal cancer is a rare cancer that develops in the peritoneum, inside the abdomen wall.
Doctors stage peritoneal cancer depending on the position and size of the tumor, where in the body it has spread from, and how fast it is likely to spread.
Primary peritoneal cancer originates in the peritoneum, and doctors stage it as either stage 3 or 4. Secondary peritoneal cancer is more common, and doctors stage it from stages 0–4. This cancer has spread to the peritoneum from another area of the body.
The outlook for those with peritoneal cancer is generally poor. Treatment typically involves surgery to remove as much of the tumor as possible, followed by chemotherapy and targeted therapy.