peritoneal-based-malignancies

Peritoneal based Malignancies - What it is

The peritoneum is a thin membrane that lines the abdominal and pelvic cavities. It covers most of the abdominal organs including liver, spleen, small and large intestines, stomach and pelvic organs. The peritoneum provides support and serves as a conduit for blood, lymph vessels and nerves.

Peritoneal based malignancies refer to cancers that either originate from the peritoneum or have spread to involve the peritoneal lining.

Tumours that arise from the peritoneum:

Malignant peritoneal mesothelioma
Primary Peritoneal Cancer

Tumours that may spread to the peritoneal lining:

Ovarian Cancer
Colorectal Cancer
Stomach Cancer
Pancreatic Cancer
Gallbladder Cancer
Appendiceal Cancer

Peritoneal based Malignancies - Symptoms

Peritoneal based malignancies may not always cause any symptoms, if it does, symptoms may include:

Abdominal pain
Bloating or abdominal swelling
Change in bowel habits, such as recurrent diarrhoea, constipation or rectal bleeding
Abnormal bleeding from the vagina
Unexplained weight loss
Loss of appetite

When to see a doctor

The symptoms above can be caused by a number of health complications and may not indicate the presence of cancer. However, make an appointment with your doctor if you have any signs or symptoms that worry you.

Peritoneal based Malignancies - How to prevent?

Currently there are no proven preventive strategies for peritoneal based malignancies. However, adopting a healthy lifestyle may help to prevent disease by:

Quitting or not starting smoking.
Eating a diet rich in fruits and vegetables.
Limiting alcohol consumption.
Regularly exercising and maintaining a healthy weight.

Peritoneal based Malignancies - Causes and Risk Factors

Factors that can increase the risk of peritoneal based malignancies:

Older age – Peritoneal based malignancies are often diagnosed in people aged 50 years and above. However, increasingly younger people are also being diagnosed with the cancer.
Gender – There is no gender predisposition to peritoneal based malignancies.
Personal history of ovarian, colorectal, stomach, pancreatic, gallbladder, or appendiceal cancer.
Family history of peritoneal, fallopian tube, or ovarian cancer.
Genetic mutations such as BRCA1 AND BRCA2.
Having endometriosis.

Peritoneal based Malignancies - Diagnosis

Diagnostic tests include:

Imaging tests

Ultrasound, MRI or CT scans may be used to produce detailed pictures that may indicate the presence of cancer.

Blood tests

A blood test that measures levels of a chemical called CA-125, Ca19-9, CEA in the blood may indicate

the presence of peritoneal based malignancies. However, these markers are not specific and high levels may be present for other reasons. If your health screen shows high levels of these markers, please head to your nearest clinic for a referral to a tertiary centre for further workup.

Lower GI series or barium enema

During this procedure, the colon and rectum are filled with a white liquid called barium, that helps x-rays show details in the large intestines, making it possible to spot tumours or other abnormalities.

Upper GI series

In this procedure, barium is swallowed so that the x-rays can show details of the oesophagus, stomach and duodenum (first part of the small intestine).

Endoscopy

A scope is used to provide direct visualisation of the lining of both the stomach and large intestine. This procedure is usually done under sedation and is generally safe. Any suspicious lesions can be biopsied for histological diagnosis.

Laparoscopy

A thin tube is passed through a small incision in the abdomen so that organs inside the abdomen can be examined. If necessary, a biopsy (a small sample of tissue) may be taken for examination and testing in the laboratory to confirm a cancer diagnosis.

Paracentesis

In cases where a biopsy is not possible or if it is suspected that the fluid build-up (called ascites) that is characteristic of peritoneal based malignancies, is due to other causes, a doctor may remove fluid from the abdomen so that it can be examined under microscope to indicate which type of cancer is present.

Peritoneal based Malignancies - Treatments

An individual with peritoneal based malignancies should be assessed by a multi-disciplinary team of specialists to determine which modality of treatment is best suited for them. All cases seen at SingHealth institutions are reviewed at a weekly multi-disciplinary tumour board, where decisions on treatment are made following discussions, so that care is holistically managed.

In the case of peritoneal based malignancies, not all patients are suitable for surgery. Those who typically are suitable for surgery are:

Patients with tumours that arise from the peritoneum.
Patients who have primary tumours in the ovary, colon and appendix, who have no evidence of distant metastasis.
Patients who are medically fit for surgery and anaesthesia.

Treatment for peritoneal based malignancies includes cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). New treatment in the form of pressurized intraperitoneal aerosolized chemotherapy (PIPAC) has emerged as an option in patients with extensive peritoneal disease that is deemed not suitable for resection.

Cytoreductive surgery (CRS)

CRS aims is to remove all visible tumours in the abdomen. Intra-abdominal organs that have tumours which can be safely removed, will be resected to ensure no disease remains. In addition, surgery to remove the involved peritoneum will be performed.

Hyperthermic intraperitoneal chemotherapy (HIPEC)

Once CRS is completed, HIPEC is administered in the operating room to treat any microscopic tumours that may be present. During this process, the chemotherapy drug is heated and kept at a temperature of 42 degrees Celsius. The heat is used to help increase the penetration of chemotherapy drug into the tissues. The chemotherapy is circulated into the abdominal cavity and then out for a constant flow using a specialised pump that moves the heated chemotherapy solution. This is done over a period of time after which the abdominal cavity is washed and the procedure is completed.

Patients with extensive peritoneal disease that cannot be completely removed may not be suitable for CRS and HIPEC. These patients may be identified pre-operatively after imaging scans or may only be identified during surgery. Disease on the peritoneum may be very small and can be difficult to detect on imaging prior to surgery.

During surgery, the surgeon may decide not to proceed if tumour spread is too extensive or if too much of the bowel has to be removed. In these cases, surgery to remove as many tumours as possible to lessen symptoms, may be an option for some patients.

Pressurized intraperitoneal aerosolized chemotherapy (PIPAC)

PIPAC is another way of introducing chemotherapy into the abdomen for patients with advanced peritoneal based malignancies. It is done with laparoscopy technique under general anaesthesia. No organs are resected during the procedure. Biopsies will be taken prior to infusion of chemotherapy.

This procedure may be repeated multiple times with or without conventional chemotherapy given in between treatment.

Peritoneal based Malignancies - Preparing for surgery

Your surgeon will perform a comprehensive medical work-up including blood tests and scans to see if you are suitable for surgery and advise you on the risks involved. This treatment recommendation is often based on consensus by a group of different specialists' opinions (tumour board), which weighs the pros and cons of every treatment strategy.

Before surgery, the anaesthesia team will also assess your fitness for surgery and advise you on various aspects of general anaesthesia aspects and pain control after surgery.

Specialist nurses will also provide pre-surgery counselling.

Peritoneal based Malignancies - Post-surgery care

As CRS and HIPEC are major procedures, post-surgery recovery has a number of different components.

Stoma

Some patients who undergo CRS will need a temporary stoma (a surgically created opening on the surface of the abdomen to divert the flow of faeces into a disposable bag worn over the stoma). The stoma allows the bowel to heal after surgery. This will be reversed after 2 months’ post-surgery, after discussion with the surgeon and medical oncologist. All patients are seen by specialist stoma nurses before and after the operation, who provide information about stoma care.

Recovery

After recovering from surgery, you will be given regular outpatient appointments to see your team of doctors. These visits may include blood tests and scans to monitor and check if the cancer recurs. It is important to follow your doctor's advice, keep to scheduled clinic visits and do the prescribed tests so that timely treatment can be administered if the cancer or other problems arise.

Peritoneal based Malignancies - Other Information

Some of the possible complications following CRS and HIPEC are listed below. Selected complications are explained in detail below. More information will be provided by your surgeon.

Early postoperative

Anastomotic leak – a serious post-surgery complication that can lead to severe intra-abdominal infection
Postoperative bleeding
Wound infection
Intra-abdominal infection/collections
Deep vein thrombosis (DVT)
Chest infection
Urinary tract infection
Prolonged ileus
Electrolyte disturbances
Immunosuppression

Late postoperative complications

Intra-abdominal infection/collections
Entero-cutaneous fistula – abnormal connection forms between skin and intestines causing discharge of intestinal content through the skin
Intestinal obstruction
Bladder and sexual dysfunction (for pelvic dissection cases)
Stoma-related complications

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