Peritoneal Surface Cancer

What Is Peritoneal Surface Cancer?

Peritoneal surface cancer is a rare type of cancer that develops in the peritoneum, the thin layer of tissue lining the inside of the abdomen and covering most abdominal organs. Even though it starts outside the ovaries, it behaves very similarly to advanced ovarian cancer and is often treated in the same way.

This cancer can spread across the abdominal cavity rather than forming a single solid tumour. Because of this pattern, symptoms tend to be vague in the early stages and may not immediately point to a specific cause.

In many cases, peritoneal surface cancer is diagnosed at a later stage, not because it grows silently, but because its symptoms can mimic common digestive or abdominal issues.

Types of Peritoneal Surface Cancer

Peritoneal cancers are usually classified based on the type of cells involved:

• Primary peritoneal carcinoma: The most common form, closely related to epithelial ovarian cancer.

• Peritoneal mesothelioma: A rare type arising from mesothelial cells lining the peritoneum.

• Secondary peritoneal cancer (peritoneal metastasis): Cancer that has spread from other organs, such as the colon, stomach, or ovaries. Cancer that spreads from other organs such as the colon, stomach, ovaries, and other abdominal organs to the peritoneum is also considered a form of peritoneal surface cancer. Earlier, these cases were often considered inoperable. However, with advanced cytoreductive surgery and HIPEC, selected patients, especially younger patients with good performance status, may still be offered curative treatment. This is one of the most important advances in modern peritoneal cancer treatment.

Each type may require a slightly different treatment approach, although there is significant overlap.

Signs and Symptoms of Peritoneal Surface Cancer

Symptoms are often subtle at first and may gradually worsen over time. Many people initially think they are dealing with digestive issues.

Common symptoms include:

• Persistent abdominal bloating

• Increase in abdominal size due to fluid (ascites)

• Feeling full quickly while eating

• Loss of appetite

• Abdominal discomfort or pain

• Nausea or indigestion

• Unexplained weight loss or, sometimes, weight gain due to fluid retention

• Fatigue

• Blood in stool

• Changes in bowel habits, such as constipation

Because these symptoms are nonspecific, they are sometimes overlooked or treated symptomatically before deeper evaluation is done. Symptoms persisting for more than 2 weeks should never be ignored. Early evaluation can significantly improve treatment options and outcomes.

Why Does Peritoneal Surface Cancer Develop?

The exact cause is not always clear, but it develops when cells in the peritoneal lining undergo genetic changes that lead to uncontrolled growth. Peritoneal surface cancer may also develop when cancers from other organs such as the colon, stomach, or ovaries spread to the peritoneum.

Risk factors may include:

• Genetic mutations such as BRCA1 or BRCA2

• Family history of ovarian or related cancers

• Increasing age

• Previous history of ovarian cancer

• Chronic inflammation of the abdominal lining

• Exposure to asbestos (linked to peritoneal mesothelioma)

In many individuals, there is no clear identifiable cause.

Diagnosis of Peritoneal Surface Cancer

Diagnosis can be challenging because symptoms are not specific, and imaging findings may overlap with other conditions.

A combination of tests is usually required:

• Physical examination: May reveal abdominal swelling or fluid buildup.

• Ultrasound: Often the first imaging test to detect fluid or masses.

• CT scan or MRI: Provides detailed images of the abdomen and helps assess disease spread.

• PET CT scan: Very important for understanding the full extent of disease spread and planning treatment. 

• Blood tests: Including tumour markers such as Including tumour markers such as CA-125, CEA, and CA 19-9 in some cases.

• If cancer is suspected to arise from the colon, a colonoscopy may be needed.

• If stomach cancer is suspected, an upper GI endoscopy may be required.

• Paracentesis: Fluid from the abdomen is removed and examined for cancer cells.

• Biopsy: A tissue sample is taken often via laparoscopy or through Ultrasound-guided peritoneal biopsy and CT-guided peritoneal biopsy to confirm the diagnosis.

• Diagnostic laparoscopy: If lesions are very small or difficult to access, a diagnostic laparoscopy with biopsy may be needed for confirmation.

A biopsy remains essential to confirm the diagnosis and determine the exact cancer type.

Treatment Options for Peritoneal Surface Cancer

Treatment usually involves a combination approach and is tailored based on how extensive the disease is and the patient’s overall condition.

Cytoreductive surgery (debulking): 

Cytoreductive surgery is a major surgery that aims to remove all visible tumour from the abdominal cavity.

This surgery can last for 8 to 10 hours and may include:

• Total peritonectomy 

• Total omentectomy 

• Multiple organ resections 

• Removal of involved abdominal structures depending on disease spread 

The goal is to remove all grossly visible disease that can be seen during surgery.

This is one of the most important steps in treatment.

• HIPEC (Hyperthermic Intraperitoneal Chemotherapy): 

HIPEC is almost always performed after successful cytoreductive surgery, especially when gross visible disease has been removed.

It involves:

• Delivering heated chemotherapy directly into the abdominal cavity 

• Done during the same anaesthesia immediately after surgery 

• Duration usually ranges from 60 to 90 minutes 

This helps destroy microscopic cancer cells that may remain after surgery and reduces the risk of recurrence.

HIPEC has significantly improved outcomes in selected patients.

Systemic chemotherapy:

Systemic chemotherapy is chemotherapy given through the bloodstream and may be recommended after surgery depending on the disease type and stage.

Targeted therapy and Immunotherapy: 

These may be used depending on:

• Genetic markers such as BRCA mutations 

• Tumour biology 

• Disease stage

• PIPAC / PIPEC

• PIPAC (Pressurised Intraperitoneal Aerosol Chemotherapy), also referred to as PIPEC in some settings, is an advanced treatment option used in selected cases after systemic therapy.

It is especially useful when complete curative surgery is not possible and helps improve disease control and symptom management. The combination of surgery and HIPEC has significantly improved outcomes in selected patients.

Recovery and Follow-Up

Recovery depends on the extent of surgery and the type of treatment received. Cytoreductive surgery with HIPEC is a major procedure and requires a longer recovery period compared to less invasive treatments.

Follow-up care may include:

• Regular imaging scans

• Monitoring tumor markers

• Nutritional support

• Management of fatigue and digestive symptoms

• Ongoing evaluation for recurrence

• Psychological and emotional support

Living with or beyond this condition often requires a multidisciplinary approach, including oncologists, surgeons, dietitians, and support teams.

Watching for Recurrence After Treatment

Instead of only focusing on early symptoms, patients should remain watchful for signs of recurrence after completing treatment.

Seek medical review if there is:

• Return of abdominal bloating 

• New abdominal swelling or fluid buildup 

• Persistent digestive symptoms 

• Unexplained weight changes 

• New pain or worsening fatigue 

• Regular follow-up is extremely important for long-term care.