Liposarcoma – Diagnostics – Overview of Information and Clinical Research

Diagnosing liposarcoma requires careful evaluation and specialized testing, as these rare cancers that develop in fat cells often grow slowly without causing early symptoms. Understanding when to seek medical attention and what diagnostic tests to expect can help patients navigate the process more confidently and ensure accurate identification of this uncommon cancer.

Introduction: When to Seek Diagnostic Evaluation

Liposarcoma is a very rare cancer that begins in fat cells, and knowing when to get checked is an important first step. Because these tumors often grow quietly without causing pain, many people don’t realize something is wrong until the growth becomes large enough to affect nearby tissues or organs. If you notice a lump under your skin that doesn’t go away, especially if it keeps getting bigger, it’s time to talk to a doctor. This is particularly important if the lump appears on your arms, legs, or in the belly area, where liposarcomas most commonly develop.^[1]

You should make an appointment with a healthcare professional if you experience any unusual symptoms that persist and worry you. For instance, if you have a growing mass in your arm or leg that causes swelling, pain, or weakness in that limb, these could be warning signs worth investigating. In the abdomen, symptoms might include persistent pain, swelling, feeling full too quickly when eating, constipation, or finding blood in your stool.^[1] These symptoms can be caused by many different conditions, so it’s essential to have them properly evaluated rather than assuming the worst or ignoring them.

Most liposarcomas grow very slowly and rarely cause pain initially, which means they can remain undetected for quite some time. You may not notice any changes in your body unless you spot a large bump on your arm or leg that refuses to disappear or continues to enlarge. Pain typically only develops when the tumor presses on a nerve or begins affecting nearby organs.^[2] For example, a liposarcoma in the lungs might make breathing difficult, while one in the belly might interfere with digestion.

⚠️ Important

Liposarcoma is not the same as a lipoma, even though both involve fatty tissue. Lipomas are benign, non-cancerous fatty lumps that are much more common, affecting about two out of every 1,000 people. They typically feel soft and rubbery, form just below the skin, and are usually no larger than 2 inches across. Liposarcomas, on the other hand, are firmer, grow deeper in the tissues, and can become much larger, especially in areas like the abdomen.^[6]

The typical person affected by liposarcoma is between 50 and 65 years old, though it can occur at any age, including rarely in children during adolescence. Men are slightly more likely to develop these tumors than women.^[2] If you fall into this age group and notice any persistent lumps or unexplained symptoms, seeking medical evaluation is a wise decision. Early detection can make a significant difference in treatment options and outcomes.

Classic Diagnostic Methods

Once you’ve discussed your symptoms with a doctor, the next step is a series of tests designed to determine whether you have liposarcoma and, if so, what type it is. The diagnostic process typically begins with imaging tests, which create detailed pictures of the inside of your body. These tests help doctors see the size and location of any suspicious masses. Common imaging tests include X-rays, which provide basic images of bones and some soft tissues; CT scans (computed tomography), which use X-rays and computers to create cross-sectional images of your body; and MRI scans (magnetic resonance imaging), which use magnets and radio waves to produce detailed images of soft tissues.^[9]

Sometimes a positron emission tomography scan, also called a PET scan, may be needed. This test uses a small amount of radioactive material to help identify areas where cells are more active than normal, which can indicate cancer. Ultrasound, which uses sound waves to create images, might also be used, particularly for examining lumps in the abdomen or limbs.^[9] These imaging tests are painless and help your medical team understand what they’re dealing with before taking the next diagnostic step.

However, imaging alone cannot definitively tell whether a lump is cancerous. To make an accurate diagnosis, doctors need to examine actual tissue from the suspicious area. This is done through a procedure called a biopsy, which involves removing a small sample of cells or tissue for testing. There are different ways to perform a biopsy depending on where the tumor is located. One common method is a needle biopsy, where a needle is inserted through the skin to extract tissue. In some cases, the biopsy sample might be taken during surgery to remove the cancer entirely.^[9]

Once the biopsy sample is collected, it goes to a laboratory where specialists called pathologists examine it under a microscope. These doctors look at the cells to determine whether they are cancerous and, if they are, what specific type of liposarcoma is present. This is a crucial step because liposarcoma comes in several different subtypes, including well-differentiated liposarcoma, dedifferentiated liposarcoma, myxoid liposarcoma, round cell liposarcoma, and pleomorphic liposarcoma. Each type behaves differently, grows at different rates, and requires different treatment approaches.^[2]

Determining the exact type of liposarcoma is extremely important and requires special expertise. Sometimes, standard microscopic examination isn’t enough, and additional testing is needed. DNA testing or other advanced laboratory techniques might be used to look for specific genetic changes in the cancer cells. This helps pathologists distinguish one type of liposarcoma from another and from other types of soft tissue tumors.^[14] Getting the diagnosis right is essential because it directly affects your treatment plan and expected outcomes.

After confirming that you have liposarcoma and identifying its subtype, your healthcare team will want to learn more about the extent of the cancer. This process is called staging, and it helps determine how much cancer is in your body and whether it has spread beyond its original location. Staging typically involves additional imaging tests to check whether the cancer has moved to other areas, such as the lymph nodes, lungs, or other organs.^[9] The stage of your cancer is one of the most important factors in deciding how to treat it.

⚠️ Important

A biopsy is always required to make a definitive and accurate diagnosis of liposarcoma. While scans can give doctors an idea of what a mass might be, only examination of actual tissue under a microscope can confirm whether it is cancer.^[14] Never skip this step, even if imaging tests suggest what the problem might be, as many conditions can look similar on scans but require very different treatments.

Diagnostics for Clinical Trial Qualification

If you’re considering participating in a clinical trial for liposarcoma, you’ll need to undergo specific tests to determine whether you qualify for the study. Clinical trials are research studies that test new treatments or combinations of treatments, and they have strict rules about who can participate. These rules, called eligibility criteria, are designed to ensure patient safety and to make sure the study produces reliable results. The diagnostic tests required for clinical trial enrollment often go beyond the standard tests used for initial diagnosis.

Most clinical trials require complete documentation of your diagnosis, including pathology reports that confirm the type and grade of your liposarcoma. You may need to provide tissue samples from your original biopsy or surgery for additional testing. Some trials require specific molecular or genetic testing of your tumor to look for particular characteristics that the experimental treatment is designed to target. For example, researchers might need to know whether your tumor has certain genetic mutations or expresses specific proteins.^[11]

Imaging tests are also standard requirements for clinical trial participation. Before you can enroll, you’ll likely need recent CT scans, MRI scans, or PET scans to measure the exact size and location of your tumors. These baseline images are crucial because they allow researchers to compare your tumor size before and after treatment to determine whether the experimental therapy is working. The trial protocol will specify exactly which imaging tests are needed and how recently they must have been performed.^[9]

Blood tests are another common requirement for clinical trial qualification. These tests check your overall health and organ function to ensure you’re strong enough to handle the experimental treatment. Typical blood work includes a complete blood count, which measures your red blood cells, white blood cells, and platelets; liver function tests, which check how well your liver is working; and kidney function tests, which assess whether your kidneys are healthy. Some trials have specific requirements about blood counts or organ function levels that must be met before you can participate.^[12]

Depending on the trial, you might also need tests to check your heart function, such as an electrocardiogram (ECG or EKG) or an echocardiogram. These are particularly important if the experimental treatment has the potential to affect the heart. Similarly, lung function tests might be required if the treatment could impact breathing. The goal of all these tests is to establish your baseline health status and ensure that participating in the trial won’t put you at undue risk.

Clinical trials often have strict rules about previous treatments. You may need to document exactly what treatments you’ve already received for your liposarcoma, including surgery, radiation therapy, or chemotherapy. Some trials are only open to patients who have already tried certain standard treatments, while others might only accept patients who haven’t received any treatment yet. Your medical records will need to clearly show your treatment history to determine if you qualify.^[11]

Finally, clinical trials may require regular repeat testing throughout the study period. This means you’ll have imaging scans, blood tests, and other assessments at specific time points during your participation. These repeated tests help researchers track how your cancer responds to the treatment and monitor for any side effects. While this means more frequent medical appointments and tests than you might have with standard treatment, it also means closer monitoring of your health, which many patients find reassuring.

Prognosis and Survival Rate

Prognosis

The outlook for someone with liposarcoma depends heavily on which type they have and where it’s located in the body. Some types, such as well-differentiated liposarcoma, grow slowly and are not typically life-threatening. These tumors can often be successfully removed with surgery, and patients may live for many years without major complications. However, even these slower-growing types can come back after treatment, sometimes many years later. The local recurrence rate can be around 10%, and recurrence has been reported even up to 25 years after the initial surgery, which is why long-term follow-up is essential.^[4]

On the other hand, more aggressive types like dedifferentiated liposarcoma, pleomorphic liposarcoma, and round cell liposarcoma are more likely to spread to other parts of the body or return after treatment. Pleomorphic liposarcoma can be very aggressive, growing quickly and spreading rapidly from its original location to other organs.^[2] When liposarcoma spreads or comes back, it becomes more challenging to treat, though treatment options are still available and can help manage the disease.

Several factors influence how well someone with liposarcoma might do. The tumor’s location matters significantly—liposarcomas in the abdomen, particularly in the area behind the belly organs called the retroperitoneum, tend to be harder to completely remove during surgery and may have a higher chance of coming back. The size of the tumor also plays a role, with larger tumors generally being more difficult to treat successfully. Additionally, whether the tumor has spread to other parts of the body at the time of diagnosis is a critical factor in determining prognosis.^[11]

Survival rate

Specific survival statistics for liposarcoma can vary widely depending on the subtype and individual circumstances, but generally, patients with well-differentiated liposarcoma that is completely removed have a favorable outlook. These tumors rarely spread to distant parts of the body and are not typically life-threatening, though they can recur locally.^[2]

For myxoid liposarcoma, which is the second most common type, outcomes depend on the proportion of round cells present in the tumor. Tumors with a higher percentage of round cells tend to be more aggressive and may have a less favorable prognosis. The presence of a round cell component may be an adverse prognostic sign.^[12]

Dedifferentiated and pleomorphic liposarcomas have a higher risk of spreading to other organs and returning after treatment, which can affect long-term survival. However, many factors influence individual outcomes, including how completely the tumor can be removed during surgery, whether the cancer has spread at diagnosis, and how well it responds to any additional treatments like radiation or chemotherapy. Because liposarcoma is rare and comes in several different forms, survival rates can vary considerably from person to person.

It’s important to remember that statistics are based on groups of people and cannot predict what will happen to any individual patient. Advances in treatment, including new targeted therapies and improved surgical techniques, continue to improve outcomes for people with liposarcoma. Your healthcare team can provide more specific information about your individual prognosis based on your particular situation.

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