Fibrosarcoma and malignant fibrous hystiocytoma (MFH) of the bone
This section gives information about two rare types of sarcoma of the bone called fibrosarcoma and malignant fibrous hystiocytoma (MFH). These two types of sarcoma of the bone are rare and different, but both are types of sarcoma known as spindle cell sarcoma. As these tumours start in the bone they are primary bone cancers. They often share similar signs and symptoms and treatment options.
We hope that the information will answer any questions that you may have about these conditions. It should ideally be read with the section on primary bone cancer which gives more information and puts this section into context.
- Malignant fibrous histiocytoma (MFH)
- Causes of fibrosarcoma and MFH
- Signs and symptoms
- How it is diagnosed
- Further tests
- Grading and staging
- Clinical trials
- Your feelings and support
Fibrosarcomas develop from fibrous (connective) tissue cells called fibrocytes. Fibrosarcoma occurs most commonly in adults, particularly during middle age. The most common site is the thigh bone (femur) and the knee.
As well as being a type of primary bone cancer, fibrosarcomas can develop in the soft tissues of the body. Soft tissue fibrosarcomas are very uncommon and include sclerosing epithelioid fibrosarcomas (SEF), desmoid tumours and dermato-fibrosarcoma protuberans (DFSP).
Malignant fibrous histiocytoma (MFH)
This is a very rare type of bone cancer that occurs in adults. It is usually found in the arms or legs, especially around the knee joint. These cancers start in fibrous tissue cells called histiocytes. This type of sarcoma tends to occur in older people (aged 40–80 years).
Malignant fibrous histiocytomas (MFH) can also develop in the soft tissues of the body, such as muscle. These tumours include storiformpleomorphic, myxoid, giant cell, inflammatory and angiomatoid MFH.
This section only discusses fibrosarcomas and malignant fibrous histiocytomas of the bone. If your cancer is one of the other types listed above, the nurses at CancerBACUP can give you further information about these.
Causes of fibrosarcoma and MFH
The exact causes of primary bone cancer are unknown. However, adults who have a bone condition known as Paget’s disease or who have been exposed to high doses of radiotherapy may have a slightly increased risk of developing bone cancer. Rarely, some bone cancers may occur in people from families where there is an inherited faulty gene that increases the risk of developing particular types of cancer.
Signs and symptoms
Pain is the most common symptom of bone cancer. However, symptoms may vary depending on the location and size of the cancer. There may be some swelling in the affected area and it may become tender to touch.
Occasionally a fever (high temperature) also develops. Primary bone cancer is sometimes discovered when a bone that has been weakened by cancer, breaks after the person has had a minor fall or accident.
Many of the symptoms described above are common to conditions other than cancer. However, any persistent bone pain, particularly if it occurs at night, should be checked by your doctor.
How it is diagnosed
Usually you begin by seeing your family doctor (GP), who will examine you and may arrange any tests or x-rays, which may be necessary. Your GP will probably refer you to a specialist surgeon (called an orthopaedic surgeon) who can carry out further investigations and decided if you need a referral to a specialist hospital or bone tumour centre for tests. Many of the specific tests for diagnosing bone tumours, such as the biopsy, require experience and specialist techniques.
The doctor at the hospital will take your full medical history before doing a physical examination. This will include an examination of the painful bone to check for any swelling or tenderness. You will probably have a blood test done to check your general health.
This involves the use of energy beams to show the structure of the bone.
MRI (magnetic resonance imaging) scan
This is a specialist scan that uses magnetism to build up cross-sectional pictures of your body. Some people are given an injection of dye into a vein in the arm to improve the image.
During the test you will be asked to lie very still on a couch inside a long chamber for up to an hour. This can be unpleasant if you don’t like enclosed spaces, so it may help to mention this to the doctor working the machine. The machine is also very noisy and you will be given earplugs or headphones to wear.
This is a more sensitive test than the simple x-ray and shows up any abnormal areas of bone more clearly. For this test, a small amount of a mildly radioactive substance is injected into a vein, usually in your arm. Abnormal bone absorbs more radioactivity than normal bone so these areas are highlighted and picked up by the scanner as `hot spots’.
For this test a small sample of the tumour is taken from the affected bone. The doctor will look at the sample under a microscope to identify the exact type of tumour that you may have.
This type of biopsy is not often used, as the needle biopsy is much quicker and simpler. In an open biopsy a small piece of bone is removed during a minor operation while you are under a general anaesthetic. It may be necessary to do this if a needle biopsy can’t be done or doesn’t give a clear diagnosis.
CT (computerised tomography) scan
A CT scan is a specialised type of x-ray. A number of pictures are taken from different angles and fed into a computer that shows detailed pictures of the inside of the body. A CT scan can show whether the cancer has spread to other parts of the body. The scan is painless and takes 10–30 minutes.
In some people with fibrosarcoma or MFH the cancer may spread to the lungs. A chest x-ray is usually done to check whether there is any sign of cancer cells in the lungs.
Grading and staging
Grading refers to the appearance of the cancer cells under the microscope and gives an idea of how quickly the cancer may develop. Low grade means that the cancer cells look very like the normal cells and they are usually slowly growing and are less likely to spread. In high-grade tumours the cells look very abnormal and are likely to grow more quickly and are more likely to spread.
Fibrosarcomas are graded from 1 to 4. Grades 1 and 2 are a low-grade cancer and grades 3 and 4 are high-grade cancer.
MFH are graded from 1 to 3. Grade 1 indicates a low-grade cancer and grades 2 and 3 are high-grade cancer.
The stage of a cancer is a term used to describe its size and whether it has spread beyond its original site. Knowing the particular type and the stage of the cancer helps the doctors to decide on the most appropriate treatment.
Most patients are grouped depending on whether cancer is found in only one part of the body, which is known as localised disease, or whether the cancer has spread from one part of the body to another (metastatic disease).
- Stage 1A The cancer is low grade and is completely contained within the hard coating of the bone.
- Stage 1B A low-grade cancer extending outside the bone into the soft tissue spaces, which contain nerves and blood vessels.
- Stage 2A The cancer is high grade and is completely contained within the hard coating of the bone.
- Stage 2B A high-grade cancer extending outside the bone into the soft tissue spaces, which contain nerves and blood vessels.
- Stage 3 The cancer can be low grade or high-grade and it is found either within the bone or extending outside the bone. The cancer has spread to other parts of the body, or to other bones not directly connected to the bone in which the tumour started.
If the cancer comes back after initial treatment, this is known as recurrent cancer.
The type of treatment you are given will depend on a number of things, including the position within the body of the cancer and its size, whether it has spread, the grade of the cancer and your general health.
As fibrosarcomas and MFH are very uncommon they are usually treated at specialist hospitals by a team of doctors and other health professionals. This means that you may have to travel some distance to have your treatment.
Most people with either a fibrosarcoma or a malignant fibrous histiocytoma will need a combination of different treatments. The treatments that may be used are surgery (where this is possible), chemotherapy and radiotherapy.
Surgery is a very important part of treatment and is used to remove the tumour from the bone. If surgery is not possible, then radiotherapy may be used instead. Chemotherapy is not commonly used as a treatment for fibrosarcoma, however it may be helpful in some situations. In MFH it may sometimes be used to shrink the tumour before surgery.
Major improvements have been made in surgery for bone cancer. In the past, it was often necessary to remove the limb if bone cancer was found. Now, however, it is often possible just to remove the affected part of the bone and some of the healthy tissue around it. The bone is then replaced with a specially designed metal replacement (prosthesis) or a bone graft (bone taken from another part of the body). If the cancer affects a bone in or near a joint the whole joint can often be replaced with an artificial one. These operations are known as limb-sparing surgery.
Unfortunately, it is not always possible to use limb-sparing surgery and sometimes removing the whole affected limb (amputation) may be the only way to treat the cancer. This is often the case if the cancer has spread from the bone into the nerves and blood vessels around it.
The type of surgery you have will depend on a number of factors. Your surgeon will discuss the different types of surgery with you in detail before any decision is made about your treatment.
It is often helpful to talk to someone who has had the same operation as you are going to have. The medical and nursing staff will be able to arrange this for you. On some wards a special counsellor may be available to discuss any worries you may have.
Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. This type of treatment is not commonly used to treat fibrosarcoma, although in certain situations it may be helpful.
People with a malignant fibrous histiocytoma may be offered chemotherapy to reduce to size of the tumour before surgery.
Chemotherapy can make you feel better by relieving the symptom but it can sometimes have unpleasant side effects. Any side effects that do occur can often be well controlled with medicine.
Radiotherapy treats cancer by using high-energy rays, which destroy the cancer cells, while doing as little harm as possible to normal cells. With fibrosarcoma, radiotherapy may be given to destroy any remaining cancer cells after surgery and can help to control the disease.
Radiotherapy is not often used to treat MFH, although it is still helpful in certain situations.
Radiotherapy can cause general side effects such as feeling sick (nausea) and tiredness. These side effects can be mild or more troublesome, depending on the strength of the radiotherapy dose and the length of your treatment. The radiotherapist will be able to advise you what to expect.
Research into new ways of treating fibrosarcoma and MFH is going on all the time. Cancer doctors use clinical trials to assess new treatments. These are especially important for finding improvements in treatments for rare cancers. Before any trial is allowed to take place, it must have been approved by an ethics committee, which protects the interests of patients taking part.
Your doctor or a research nurse must discuss the treatment with you so that you have full understanding of the trial and what it means to take part. You may decide not to take part or withdraw from a trial at any stage and will then receive the best standard treatment available.
The section on understanding cancer research trials explains clinical trials in more detail.
After your treatment is completed, you will have regular check-ups and possible scans or x-rays. These will probably continue for several years. If you have any problems, or notice any new symptoms in between these times, let your doctor know as soon as possible.
For people whose treatment is over apart from regular check-ups, the section on adjusting to life after cancer, gives useful advice on how to keep healthy and readjust to life.
Your feelings and support
The need for practical and emotional support will, of course, be individual and may depend on the treatment you receive and any side effects the treatment may cause. Your specialist will inform you of any potential side effects and how to deal with them before you agree to treatment.
Many different emotions may affect you. Anger, guilt, anxiety and fear are some of the most common feelings that people have. You may find yourself tearful, restless and unable to sleep. You may have feelings of hopelessness and depression. These are all normal reactions, but it is often difficult and distressing to admit to them.
You do not have to cope with these feelings on your own and there are people available to help you. You may find it helpful to talk to your family and friends about how you are feeling.
Some hospitals have their own emotional support services with specially trained staff and some of the nurses on the ward will have received training in counselling. You may feel more comfortable talking to a counsellor outside the hospital environment or a religious leader.
CancerBACUP can put you in touch with counselling services in your area. You nmay also find the section on how to deal with the emotional effects of cancer helpful.
For more information contact CancerBACUP’s Cancer Support Service.
This section has been compiled using information from a number of reliable sources including;
- Oxford Textbook of Oncology (2nd edition). Eds. Souhami et al. Oxford University Press, 2002.
- Textbook of Uncommon Cancer (2nd edition). Eds. Raghavan et al. Wiley Publishers, 1999.
- Pathology and Genetics of Tumours of Soft Tissue and Bone – World Health Organization Classification of Tumours. Fletcher et al. Oxford University Press, 2002.
For futher references, please see general bibliography.
I am going to have a course of radiotherapy to treat my cancer. The doctors took a blood test today and when I asked about this they said it was important to make sure I wasn’t anaemic before I had the treatment? Why is this?
Radiotherapy uses a type of radiation, called ionising radiation, to destroy cancer cells. There are several types of ionising radiation including x-rays, gamma rays and beta rays. Most radiotherapy treatment for cancer use x-rays.
Ionising radiation works by releasing chemicals in the nucleus of cells. These chemicals, called free radicals, damage the DNA, the genetic material that is vital for the cell to multiply. If the DNA is sufficiently damaged by the radiation then it will not be able to divide and will die off.
In order for the radiotherapy to release the free radicals that damage the DNA there needs to be a good supply of oxygen in the cells. If the cells are starved of oxygen then this actually protects them against the effects of the x-rays and makes treatment less effective.
Oxygen is carried to the tissues and cells in our bodies by the haemoglobin in the red blood cells. If we are anaemic then the haemoglobin level in the blood is low, and so the amount of oxygen carried by the blood to our cells is reduced.
So in order to get the best results from a course of radiotherapy it is important to be sure that you are not very anaemic before you start treatment.
If you are anaemic then your doctors may well suggest a blood transfusion before you start your treatment. This will boost your haemoglobin level and will increase the oxygen in your blood, which will increase the chances of success from your radiotherapy treatment.
I have recently finished treatment for a cancer. My doctors have given me the all clear but how can I be sure I am cured and the cancer won’t come back?
Very often when a cancer is treated the treatment will take away all evidence of that cancer: symptoms will disappear, physical examination and special tests (like blood tests and scans) will all go back to normal. All the appearances will suggest that the problem has been cured.
But sometimes there will be microscopic traces of the cancer left behind. Because they are so tiny these traces will not cause any symptoms and they will be too small to show up on even the most careful of examinations and most sensitive of special tests. These tiny clusters of cancer cells may lie dormant for months or years but may eventually grow and the cancer may come back.
Since these minute cells that might have been left behind cannot be detected in any way it is impossible to give an absolute guarantee that a cancer has been cured after treatment.
Having said this, very many people are cured of their cancer by modern day treatment. The chances of getting a cure depend on the type of cancer that someone has, how advanced (how large it was and how far it had spread) at the time it was first discovered (this is sometimes known as the ‘stage’ of the cancer) and how well that cancer responds to treatment.
There are now masses of statistics which doctors can use as a guide to predicting the chances of a cure for any particular cancer at any particular stage. These show that for some of the more curable types of cancer the chances of the cancer coming back after treatment are very small indeed, particularly if it was discovered at an early stage. Whereas for other types or cancers diagnosed when they were more advanced, the outcome is likely to be poorer.
These figures are only ‘statistics’ which means they cannot absolutely predict what will happen to an individual but they do give a good idea of the ‘chances’ of whether, or not, someone will be cured. So doctors rely on these figures for deciding what the likely outcome is for each person at the end of their treatment.
These days many many people are cured of their cancers. So if your doctors have given you the ‘all clear’, although there is no absolute way of proving they are right and guaranteeing you are cured, they obviously think your chances of success are excellent and you should look forward to the future with confidence.
My mother is having treatment for a cancer. The doctors have said she cannot be cured but have told her that because of treatment her condition is now stable. What does this mean?
Despite the advances that have been made in the treatment of cancer there are still many tumours that cannot be cured. In these situations it often possible for different treatments to stop the growth and spread of the cancer, or even to shrink it for a period of time.
Depending on the type of cancer and treatment which has been given this period of time when the tumour is no longer growing may last from a few weeks to a number of years.During this time the tumour is said to be under control or ‘stable’.
Other phrases which are sometimes used to describe this situation are ‘static disease’ and ‘ISQ’ (in status quo). If the cancer has shrunk by at least 50% before the period of ‘stabilisation’ this may be referred to as a ‘partial remission’ or ‘partial regression’ or ‘partial response’ (all three terms mean the same thing).
Small changes in tumour size, either recorded by direct measurement or by looking at images on x-rays or scans are difficult to assess precisely. Therefore there is general agreement among cancer specialists that in order for a cancer to show signs of progression, or a relapse, there must be a greater than 25% change in the measurements that have been used to assess it. So provided that any change is less then this level, and assuming there has been no other evidence to suggest the disease is becoming active again), then the condition will still recorded as being ‘stable’.
I have cancer and have been told I will need radiotherapy. I am so frightened that the radiotherapy will burn me. I have heard such a lot of stories about this. What can I do?
In the early days of radiotherapy treatment, skin burns during treatment and sometimes permanent damage or scarring of the skin, was common.
This changed during the late 1950s and 1960s as two new types of
machine were introduced to give the radiotherapy treatment. These are
called Linear Accelerators and Cobalt Units. These machines produce
irradiating rays of a much greater energy than the previous machines.
This higher energy of the rays give the treatments greater accuracy and
greater penetration of the tissues (allowing treatment of cancers deep
inside the body and also reduce skin damage. This is because the high
energy rays pass through the first centimetre or two of the first tissue
they meet, before they actually begin to give out any radiation.
Skin problems are uncommon with modern radiotherapy treatment. Occasionally skin problems can occur because of the location of the cancer and the area of the body treated. Usually this will cause no more than some temporary pinkness or redness of the skin for a week or two after treatment. If any soreness does develop it will only last a short time and can usually be eased with creams or lotions, which you will be given at the hospital. Severe or permanent skin damage is rare indeed.
The fact that skin damage was common forty or fifty years ago means that people can remember friends or relatives who had bad experiences with their radiotherapy treatments which probably account for the stories you have heard. Nowadays the situation is very different and things have improved enormously.
I am about to have a course of radiotherapy following an operation for cancer. If I go on holiday in a few months from now, will I be able to go out in the sun?
Radiotherapy is almost always a local treatment, limited to a particular part of the body. Only the skin in that area will be irradiated and the skin elsewhere will not be affected.
The doses of radiotherapy used can vary but even with quite high doses modern radiotherapy machines usually cause a little skin irritation. Even so this does mean that the skin which has been irradiated will be more sensitive to sunlight than your normal skin.
The degree of sensitivity will vary from person to person. The increased sensitivity also reduces gradually with time but probably never disappears completely.
Having had radiotherapy does not mean you must avoid the sun completely but you should take care over exposing the treated skin. It is very important to cover the treated area for at least the first year after radiotherapy. Wear clothing made of cotton or natural fibres which have a closer weave and offer more protection against the sun. Even after this time the area treated will be more delicate, so extra care should be given. You should also use a high factor sunscreen (of at least factor 15). Remember, too much sunbathing does carry the risk of leading to skin cancer and should be avoided.
Very occasionally radiotherapy is given to the whole body. In this situation the doses are normally quite low but you should still take precautions in exposure to strong sunlight. Seek advice from your doctors if you are having this type of treatment.