Liposarcoma

Liposarcoma is a rare type of cancer that begins in fat cells and can develop anywhere in the body, though it most commonly appears in the muscles of the limbs or deep within the belly.

Table of contents

• What is Liposarcoma?
• Types of Liposarcoma
• Who is Affected?
• Signs and Symptoms
• Causes and Risk Factors
• How is Liposarcoma Diagnosed?
• Treatment Options
• Living with Liposarcoma

What is Liposarcoma?

Liposarcoma is a rare type of cancer that starts in the fat cells of the body^[1]. It belongs to a group of cancers called soft tissue sarcomas, which develop in the body’s connective tissues^[1]. While liposarcoma can begin in fat cells anywhere in the body, it most often develops as a growth of cells in the belly, arms, and leg muscles^[1].

This cancer is quite uncommon. Liposarcoma affects about 1 in 100,000 people in the United States each year^[2]. It represents the most common type of soft tissue sarcoma, making up less than 20% of all soft tissue sarcomas^[4].

Most liposarcomas grow very slowly and rarely cause pain^[2]. You may not notice any changes in your body unless you see a large bump on your arm or leg that doesn’t go away or gets larger over time^[2]. The cancer may cause pain if it presses on a nerve or affects nearby organs^[2].

Types of Liposarcoma

There are several types of liposarcoma, and each type behaves differently. The type of liposarcoma you have is very important because it affects your treatment plan and what to expect from the disease^[2].

Well-differentiated liposarcoma is the most common type, making up 30% to 50% of all liposarcomas^[2]. These are slow-growing, painless tumors that may appear in the arms, legs, or trunk^[2]. When this type of tumor develops in the back of the abdomen, it is specifically called a well-differentiated liposarcoma^[2]. Doctors sometimes call these tumors atypical lipomatous tumors^[2]. These tumors are generally slow-growing with a low risk of spreading to other parts of the body^[4].

Myxoid liposarcoma and round cell liposarcoma are the second most common types, accounting for about 30% of all liposarcomas^[2]. Unlike other types, myxoid liposarcoma may affect people between ages 35 and 55^[2]. Tumors of this type usually develop in the legs^[2]. This cancer can spread to nearby soft tissue, including muscle and skin, and can also appear in bones such as the pelvic bones or spine, or organs such as the heart, lungs, or esophagus^[2]. The term “round cell” refers to how tumor cells look when viewed under a microscope, and round cell liposarcomas are an aggressive form of the disease^[2].

Dedifferentiated liposarcoma can develop in people who already have well-differentiated liposarcoma^[2]. Unlike the well-differentiated type, this is usually a fast-growing tumor^[2]. It is much more common in the back of the abdomen, known as the retroperitoneum^[4].

Pleomorphic liposarcoma is a rare, fast-growing tumor that can be very aggressive^[2]. It can grow very fast and quickly spread from where it started to other areas of the body^[2].

Who is Affected?

Liposarcoma typically affects more men than women^[2]. It is most often found in men between ages 50 and 65, though one type of liposarcoma affects people ages 35 to 55^[2]. The average age of diagnosis is 50 years^[4].

Although liposarcoma happens most often in older adults, it can happen at any age^[1]. There have been case reports of childhood-onset, though this is very rare^[4]. There is no significant association with race or gender, though a slight male predominance has been reported in some studies^[4].

Signs and Symptoms

Liposarcoma symptoms depend on the part of the body where the cancer forms^[1]. At an early stage, liposarcoma typically does not show any symptoms and frequently goes unnoticed^[6]. It usually stays undetected until the tumor in the affected area is large enough to press on neighboring tissue, causing pain or decreased function^[6].

When liposarcoma develops in the arms and legs, it can cause several symptoms. You may notice a growing lump of tissue under the skin^[1]. The affected area may become painful or swollen^[1]. You might also experience weakness of the affected limb^[1]. Sometimes the tumor can be detected as a deep-seated mass to the touch^[6].

When liposarcoma forms in the belly, it can cause a different set of symptoms. You may experience abdominal pain or swelling^[1]. Some people feel full sooner when eating than they used to^[1]. Other symptoms can include constipation and blood in the stool^[1]. Tumors in the belly can get quite big before they cause problems^[9].

In some cases, liposarcoma can cause general symptoms that are not specific to any one location. These may include bloody vomit, nausea, unintended weight loss, fevers, chills, fatigue, and night sweats^[6].

Causes and Risk Factors

The exact cause of liposarcoma is still unknown^[4]. The prevailing opinion is that the disease starts when a type of fat cell called an adipocyte progenitor stops developing normally^[11]. The cancer occurs when cells in the body change and grow out of control^[4].

It is important to note that liposarcomas do not develop from lipomas, which are completely benign fatty lumps^[4]. No specific genetic causes have been identified for liposarcoma^[6].

The American Cancer Society has identified some apparent risk factors for soft tissue sarcomas like liposarcoma. These include exposure to radiation, especially radiation therapy used to treat other cancers^[4]. Certain family cancer syndromes, such as neurofibromatosis and Li-Fraumeni syndrome, may increase risk^[4]. Damage or trauma to the lymphatic system and exposure to toxic chemicals have also been identified as possible risk factors^[4]. However, multiple cases exist where patients have no apparent risk factors for the disease^[4].

How is Liposarcoma Diagnosed?

If you have symptoms that worry you and don’t go away, you should make an appointment with a doctor or other health care professional^[1]. Your healthcare provider will ask you about your health history, symptoms, risk factors, and family history of disease, and will perform a physical exam^[4].

Several tests and procedures are used to diagnose liposarcoma. Imaging tests create pictures of the inside of the body and help show the size of the liposarcoma^[9]. These tests may include X-ray, CT scan, and MRI^[9]. Sometimes a positron emission tomography scan, also called a PET scan, is needed^[9].

A procedure to remove some cells for testing is called a biopsy^[9]. A biopsy is always required to make a definitive and accurate diagnosis^[14]. The sample might be removed with a needle put through the skin, or the sample might be taken during surgery to remove the cancer^[9]. The type of biopsy depends on the cancer’s location^[9].

The biopsy sample goes to a lab for testing. Doctors who specialize in analyzing blood and body tissue, called pathologists, test the cells to see if they’re cancerous^[9]. Other special tests give more details^[9]. Determining which type of liposarcoma a patient has is extremely important and requires special expertise; sometimes DNA testing is also required^[14].

After a diagnosis of liposarcoma, you’ll likely need other tests to help your healthcare providers learn more about the cancer and determine the stage^[4]. The stage is how much and how far the cancer has spread in your body and is one of the most important things to know when deciding how to treat the cancer^[4].

Treatment Options

Treatment for liposarcoma usually involves surgery to remove the cancer^[1]. The goal of surgery is to remove all of the cancer cells^[9]. Whenever possible, surgeons work to remove the entire liposarcoma without damaging any surrounding organs^[9].

If a liposarcoma grows to involve nearby organs, removal of the entire tumor may not be possible^[9]. In those situations, your health care team may recommend other treatments to shrink the liposarcoma, making it easier to remove during an operation^[9].

Radiation therapy uses powerful energy beams to kill cancer cells^[9]. The energy can come from X-rays, protons, or other sources^[9]. Radiation may be used after surgery to kill any cancer cells that might be left behind^[9]. It may also be used before surgery to shrink the tumor^[9]. Radiation therapy may be a valuable addition to surgery, especially for the myxoid variant of liposarcoma^[12].

Chemotherapy uses drugs to kill cancer cells^[9]. The use of chemotherapy in liposarcomas remains experimental, though patients with large high-grade liposarcomas may benefit from treatment that combines chemotherapy with radiation^[12]. Research suggests that myxoid liposarcoma is relatively chemosensitive compared to other types of liposarcoma, particularly dedifferentiated and well-differentiated tumors^[12].

Two medications have been specifically approved for unresectable or metastatic liposarcoma in patients who have received prior treatment. Trabectedin was approved in 2015, and eribulin was approved in 2016 for this purpose^[12].

Some types of liposarcoma may come back after treatment, requiring additional treatment and long-term follow-up to catch new tumors before they can spread^[2]. Even well-differentiated types that are slow-growing have a high local recurrence rate of 10%, even up to 25 years after removal^[4].

Living with Liposarcoma

After treatment for liposarcoma, it’s important to keep in close contact with your doctor^[17]. The side effects you experience depend on the type of treatment you have^[17].

All surgery has risks, including reaction to anesthesia, pain, bleeding, blood clots, damage to organs close to the surgery area, infection, and swelling of your arm or leg^[17]. How long it takes you to recover depends on the type of surgery you have^[17].

If you receive radiation therapy, your side effects depend on where the radiation is focused^[17]. You might notice problems like redness, blistering, or peeling at the area of the radiation, fatigue, or nausea and vomiting^[17]. Most radiation side effects go away after treatment stops^[17].

If you get chemotherapy, you may experience side effects such as nausea and vomiting, loss of appetite, hair loss, mouth sores, and fatigue^[17]. Most side effects from chemotherapy go away after you stop treatment^[17].

Fear of recurrence is a major concern for many people living with liposarcoma, especially given the high recurrence rates for some types like dedifferentiated liposarcoma^[21]. Balancing fear with wellness and resilience is a constant effort^[21]. Many people find it helpful to focus on what they can control, practicing meditation, mindfulness, and breathing techniques to maintain a positive mindset^[21].

Exercise can play an important role in cancer recovery. Research shows that exercise reduces inflammation, boosts energy, improves mental health, and helps manage weight—factors that may reduce recurrence risk^[21]. Today, exercise for cancer survivors focuses less on appearance and more on building mental and emotional resilience, functionality, and control^[21].

In terms of nutrition, focusing on nutrient-dense foods and staying well hydrated is important^[21]. Enjoying life is part of healing, so maintaining balance and including foods you enjoy can be part of a healthy approach^[21].