Pseudomyxoma peritonei (PMP)
Pseudomyxoma peritonei (PMP) is a rare, usually slow-growing, cancer of the appendix.
We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you are having your treatment.
Pseudomyxoma peritonei (PMP) usually begins as a slow-growing tumour in the appendix, called a Low-Grade Mucinous Appendiceal Neoplasm (LAMN). Rarely, PMP starts in other parts of the bowel, ovary or bladder.
Over time, the tumour produces a jelly-like substance called mucin. This can cause the appendix to swell up like a balloon. The tumour can then break through the wall of the appendix and spread tumour cells into the lining of the tummy (the peritoneum).
The tumour cells and mucin build up in the lining of the tummy, putting pressure on the bowel and causing symptoms. It can be many years before symptoms become obvious. Unlike other cancers, PMP rarely spreads via the lymphatic system or the bloodstream. It usually remains inside the tummy, spreading along its internal surfaces.
Causes of pseudomyxoma peritonei
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The cause of PMP is unknown.
Signs and symptoms of pseudomyxoma peritonei
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Most people don't have any symptoms for a long time. When symptoms occur they may include any of the following:
slow increase in waist size
hernia (a swelling on the abdomen)
loss of appetite
unexplained weight gain
abdominal or pelvic pain
changes in bowel habits
Most people with these symptoms won't have PMP, but it's important to have any symptoms checked by your doctor.
How pseudomyxoma peritonei is diagnosed
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PMP can be difficult to diagnose. It may be found during investigations into abdominal symptoms, or it may be discovered during an operation for another problem.
CT (computerised tomography) scan
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the body. The scan is painless. It can help to find where the tumour started and check whether it has spread within the abdomen. It usually takes 10-30 minutes. CT scans use a small amount of radiation, which is very unlikely to harm you and won't harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. For a few minutes, this may make you feel hot all over. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it's important to let your doctor know beforehand.
Sometimes the pictures from the CT scan are enough to make the diagnosis, but sometimes biopsies or an operation are needed to be sure of the diagnosis of PMP.
The treatment of PMP depends on a number of factors. These include how far the tumour has spread and your general health. Some of the standard cancer treatments, such as radiotherapy, aren't suitable for treating PMP. This is because PMP cells aren't sensitive to radiotherapy and they are often spread over too large an area for this treatment.
You may be offered surgery to treat this kind of cancer. There are two types of surgery:
Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).
Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC)
This may be an option for some people. It‘s an intensive treatment that aims to remove the tumour to try to cure PMP. It is also known as the Sugarbaker technique (named after the surgeon who first developed it). It involves removing the lining of the abdomen or organs such as the bowel, omentum (fatty tissue in the tummy) and gallbladder. In women, the womb (uterus) and ovaries may also be removed. About half (50%) of people who have a Sugarbaker operation will need a stoma (colostomy). Most of the stomas are temporary and will be reversed after about six months.
Once the surgeon has removed all or most of the tumour, a heated chemotherapy drug is put in the tummy (hyperthermic intraperitoneal chemotherapy) for 90 minutes during the operation. The combination of the chemotherapy drug and heat aims to kill any tumour cells that are left behind.
This is a major operation and may take up to 10 hours. Afterwards, you’ll be nursed in a critical care unit for several days and will stay in hospital for about 2 weeks. This operation has potentially serious complications and the surgeon will discuss these with you.
The National Institute for Health and Clinical Excellence (NICE) is an organisation that currently advises doctors on treatments for all types of illness. It has produced guidelines about this type of surgery with intraperitoneal chemotherapy. You can read the guidelines on the NICE website.
It's very important to discuss this operation with specialist doctors, as the Sugarbaker technique is a very complicated procedure and isn't suitable for everyone. It should only be carried out at a specialist centre. There are two in the UK:
This is done when it’s not possible to have cytoreductive surgery. It aims to remove as much of the tumour as possible to reduce the symptoms of the cancer. This may involve removing the omentum (fatty tissue in the tummy) and part of the bowel. In women, the womb (uterus) and ovaries may also be removed.
Unfortunately, this surgery will not take away all the tumour cells and the PMP is likely to grow back. Further debulking operations may be needed. However, each operation becomes more difficult to do, with less benefit and more risks of complications each time.
Sometimes, a permanent stoma is needed after debulking surgery. It can help to prevent the bowel from becoming blocked (obstructed). Your specialist nurse can give you more information about looking after a stoma.
Chemotherapy can be used to treat PMP. Some people who can’t have surgery may benefit from chemotherapy. It does not cure the cancer but can be used to slow it down. Research into other treatments for PMP is ongoing and advances are being made. Cancer specialists use clinical trials to assess new treatments. You may be asked to take part in a clinical trial. Your doctor must discuss the treatment with you so that you have a full understanding of the trial and what it means to take part.
For some people, the risks of treatment may outweigh the potential benefits, especially as this can be a slow-growing cancer. If you're in this situation, your specialist may suggest watchful waiting. This involves being monitored closely with regular check-ups. Only if the PMP begins to cause you problems will your specialist discuss starting treatment.
During diagnosis and treatment you may experience many different emotions including anger, resentment, guilt, anxiety and fear. These are all normal reactions and are part of the process many people go through in trying to come to terms with their illness.
Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it. You may wish to contact our cancer support specialists for information about counselling in your area.
It can be difficult to find support if you have a rare cancer. Some people find it helpful to share their experiences at a local cancer support group. Others may want to contact people with the same condition. Internet support groups provide resources and support to people with rare intestinal cancers like PMP. One such support group is Pseudomyxoma Survivor. This is a UK charity that aims to raise awareness of the condition and to provide emotional and practical support.
The two national treatment centres for PMP (see above) can also provide contact details for people who are happy to speak to others who are newly diagnosed, or who are about to start treatment.
This information has been compiled using information from a number of reliable sources, including:
Sugarbaker PH. New standard of care for appendiceal epithelial neoplasms and pseudomyxoma peritonei syndrome. Lancet Oncology. 2006. (7): 69–76.
Bryant J, et al. Systematic review of the Sugarbaker procedure for pseudomyxoma peritonei. British Journal of Surgery. 2005. 92: 153–158.
Miner TJ, et al. Long-term Survival Following Treatment of Pseudomyxoma Peritonei. Annals of Surgery. 2005. (241) 2: 300–308.
Complete cytoreduction for pseudomyxoma peritonei (Sugarbaker technique). April 2004. National Institute for Health and Clinical Excellence (NICE).
Christie Hospital NHS Trust. Pseudomyxoma Peritonei (PMP) Information Sheet. 2006. www.christie.nhs.uk/patientinfo/booklets/Textbooklets/pmp/pmp.htm (accessed January 2009).
Sugarbaker Oncology Associates. Sugarbaker Oncology Associates Speciality Section for the Treatment of Pseudomyxoma Peritonei Syndrome. www.surgicaloncology.com (accessed January 2009).
www.cancerresearchuk.org (last accessed February 2013).
www.uptodate.com (last accessed February 2013).
With thanks to Mr Paul Fulford, Consultant Colorectal Surgeon; and the people affected by cancer who reviewed this edition.
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