Liposarcoma is a rare type of sarcomacancer arising from bones and/or soft tissue that develops from lipocytes (fat cellsthe basic structural and functional unit of all living things). It can occur in any part of the body, but is most commonly found in the muscles of the limbs (arms and legs) or in the abdomenstomach, stomach area, belly. Liposarcoma is the most common type of soft tissuetissue/the material that joins, holds up or surrounds inside body parts such as fat, muscle, ligaments and lining around joints sarcoma in adults.
Liposarcoma is more common in males, and is generally diagnosed between the ages of 40-60. However, it can develop at any age. Paediatric cases of liposarcoma are generally diagnosed in a patients’ teen years or in their early 20’s.
Types of Liposarcoma
There are four types of liposarcoma, which are classified by their cellular appearance under the microscope, and the genetic mutations involved.
Well-differentiated liposarcoma
The well-differentiated subtype is the most common type of liposarcoma. This type generally forms in the limbs or in the retroperitoneuma space located behind the abdomen that contains many important bodily structures, such as the kidneys, and is often associated with a mutation on chromosome 12. It is usually low-grade and less aggressive than other types of liposarcomas.
Dedifferentiated liposarcoma
Dedifferentiated liposarcomas are the second most common subtype of liposarcoma. It often develops as the result of a well-differentiated liposarcoma, and usually occurs in the limbs or retroperitoneum. It tends to be more aggressive than the well-differentiated subtype, and has a higher metastasiswhen the cancer has spread to other parts of the body, also known as mets rate.
Myxoid liposarcoma
Myxoid liposarcoma is a less common form of liposarcoma. It is often the result of a genetic mutation that affects chromosomes 12-16. Myxoid liposarcomas are more common in the paediatric age groups, and usually develops in the limbs. It is usually a low-grade cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs.
Round cell liposarcoma
Round cell liposarcoma is a high-grade form of myxoid liposarcoma. This type generally forms in the leg. This subtype is generally more aggressive and may have a less favourable prognosisto predict how a disease/condition may progress and what the outcome might be.
Pleomorphic liposarcoma
Pleomorphicmany forms; cells that have different size, shape etc. liposarcomas are the rarest form of liposarcomas. This subtype usually develops in the limbs, and is more common in older populations. It is often high-grade with high recurrenceto occur or happen again and metastasis rates, and often spreads to the lungs. It is associated with mutations in the RB (retinoblastoma) tumoura tissue mass that forms from groups of unhealthy cells suppressor gene.
Treatment
If liposarcoma is detected, it will be staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissuea group of cells that work together to perform a function.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health. In adult patients, your tumour will be staged and graded to help determine the best treatment option for you. There is currently no standard staging system for children with liposarcomas.
The treatment options for adults and children with liposarcomas are similar. These options may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Tumour resectionsurgical removal of tissue or part/all of an organ (depending on the location).
- Amputationcomplete or partial removal of a limb (in extreme cases only).
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Targeted therapymedication that targets specific molecular features of cancer cells.
- Immunotherapya treatment that uses a person's immune system to fight cancer.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Some of the riskthe possibility that something bad will happen factors associated with liposarcoma include:
- Prior radiation treatment.
- A family history of cancer.
- Prior damage to the lymphatic systema network of tissues and organs that help our bodies fight infection and disease.
- Exposure to certain hazardous chemicals, such as vinyl chloride.
- Certain genetic syndromes.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
In the early stages of liposarcoma, there may be no signs of the disease. As the cancer progresses, some of the following symptoms may appear.
Symptoms of liposarcoma in the limbs include:
- A growing lump under the skin.
- Pain and swelling in the affected region.
- Weakness of the affected limb.
- Numbness in the affected region.
Symptoms of liposarcoma in the abdomen include:
- Abdominal pain, cramping and/or swelling.
- Loss of appetite/feeling full after little food.
- Constipationa condition where a person has difficulty passing faeces/stools.
- Bloodthe red bodily fluid that transports oxygen and other nutrients around the body in stoolwaste product from the bowel sent to the anus for removal; also known as faeces or poo.
- Black/tarry stool.
- Unexplained weight loss.
- Blood in vomit.
Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.
Diagnosis
If your doctor suspects you have a liposarcoma, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- X-raya type of medical imaging that uses x-ray beams to create detailed images of the body .
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
