Peritoneal cancer affects the peritoneal cavity, a part of the abdomen. Some types of peritoneal cancers affect females, whereas others are common in males. There are some risk factors for this cancer, such as genetic mutations and hormone replacement therapy.
This article is about peritoneal cancer and will describe and compare this cancer to ovarian cancer. It will then provide further information about this condition, including the risk factors, symptoms, treatment, and prognosis of peritoneal cancers.
A note about sex and gender
Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.
The boundaries of the peritoneal cavity
- anterior abdominal muscles
- vertebrae — bones of the spine
- pelvic floor — a group of muscles and ligaments that support the:
- diaphragm — the thin muscle below the lungs and heart that separates the chest from the abdomen
What the cavity contains?
The peritoneal cavity contains the:
- omentum — a fold of the peritoneum, the thin tissue that lines the abdomen, surrounding the stomach and other abdominal organs
- ligaments — connect bones to other bones
- mesentery — composed of two thin layers of tissue, which surround and contain the vascular (blood) and lymphatic (lymph nodes) structures supplying either the small intestine or colon
In peritoneal cancer, cancer cells grow within the serous membrane, a component of the peritoneal cavity.
There are two main types of peritoneal cancer: primary and secondary.
Primary peritoneal cancer (PPC) is when cancer originates in the peritoneal cavity itself. Secondary peritoneal cancer is when cancer spreads from a different body part to the peritoneal cavity.
PPC is rare. Data collected in the Czech Republic for a 2021 study suggests that this peritoneal cancer may affect around
Vs. ovarian cancer
Ovarian cancer can also cause secondary peritoneal cancer. Indeed, in
There are several risk factors for peritoneal cancer, and the
- a family history of peritoneal cancer
- certain inherited genetic mutations of the BRCA genes, such as BRCA1 and BRCA2 mutations
- postmenopausal hormone replacement therapy
- a high BMI
- greater height, in some cases
Who else is affected?
Researchers remain uncertain about all of the possible causes of peritoneal cancer. However, scientific work has uncovered some possible causes or contributing factors.
Many things can cause primary peritoneal cancers. EOPPC may arise due to genetic mutations. Scientists found a BRCA1 gene mutation in around
A secondary peritoneal cancer has the same cause as whichever cancer it came from. For example, if someone develops peritoneal cancer from ovarian cancer, both cancers will have the same cause. Several genetic mutations, such as those in the KRAS and BRAF genes, are
Anyone experiencing symptoms of peritoneal cancer should seek a doctor’s advice.
Doctors only have two stages for primary peritoneal cancers — stages 3 and 4. At stage 3, the tumor solely exists within the peritoneal cavity. At stage 4, cancer has metastasized to other body parts.
These stages also have sub-divisions:
- Stage 3A: Cancer exists within the pelvic organs and the abdomen’s lymph nodes.
- Stage 3B: Cancer exists within the peritoneum outside the pelvis and within the lymph nodes outside the peritoneum. The tumor is 2 centimeters (cm) or less.
- Stage 3C: This is similar to stage 3B, except the tumor is more than 2 cm.
- Stage 4A: There is a buildup of fluid around the lungs.
- Stage 4B: Cancer has spread to body parts beyond the peritoneal cavity, such as the lungs, liver, or groin lymph nodes.
By contrast, secondary peritoneal cancers have five stages:
- Stage 0: Any existing cancer is microscopic.
- Stage 1: A tumor exists in one part of the abdomen. It is less than 5 millimeters (mm).
- Stage 2: The tumor is still less than 5 mm. However, it begins to affect the whole abdomen.
- Stage 3: Several tumors exist, and they are larger than 5 mm but smaller than 2 cm.
- Stage 4: Several larger tumors exist, and they are larger than 2 cm.
Outlook based on stage
The survival rate for primary peritoneal cancers is around
Secondary peritoneal cancers of stages 0–2 have a survival rate of 5–10 months. Later stages have a survival rate of 2–3.9 months.
Scientists continue to improve cancer treatment options, and the outlook varies based on cancer stage and treatments available.
To diagnose cancer, doctors biopsy tissue samples or perform a paracentesis — a body fluid sampling procedure.
Scientists also have
- Imaging techniques: Technologies such as CT, PET, and MRI scans can help doctors find tumors within the peritoneum.
- Paracentesis: The removal of fluid samples from the abdomen. Doctors can test those samples for cancer cells.
- Laparoscopy: This involves using keyhole surgery to remove tiny samples of suspected tumors. Doctors can then test these samples in the laboratory.
In some cases, doctors may need to use several diagnostic techniques for one person.
Treatment options for peritoneal cancer will vary from person to person. However, studies show that combined approaches tend to be the
A combined approach will include surgery to remove tumors and treatments
Peritoneal cancer affects the peritoneal cavity. It can arise for many reasons, most of which are unknown but can include a combination of medical, genetic, or lifestyle factors. Doctors will use various imaging methods and invasive procedures to diagnose this type of cancer.
Scientists continue to improve treatment options for people with peritoneal cancer to improve their general outlook.