Liposarcoma Metastatic
Liposarcoma metastatic is a rare and serious condition where liposarcoma, a cancer that begins in fat cells, spreads from its original location to other parts of the body. Understanding the behavior of different liposarcoma types, their patterns of spread, and available treatment options is crucial for patients facing this challenging diagnosis.
Table of contents
- What is liposarcoma and how does it spread
- Types of liposarcoma and their metastatic potential
- Where liposarcoma spreads
- Outlook and survival
- Treatment approaches for metastatic disease
What is liposarcoma and how does it spread
Liposarcoma is a rare type of cancer that starts in fat cells and belongs to a group of cancers called soft tissue sarcomas, which develop in the body’s connective tissues[1]. This cancer most often begins in the deep soft tissues of the body, including the belly (also called the abdomen), arms, and legs[2][3].
Liposarcoma is one of the most common types of soft tissue sarcoma in adults, accounting for about 20% of all sarcomas[2][5]. It typically affects people between the ages of 50 and 65, with a slight preference for men, though it can occur at any age[2][4].
When liposarcoma spreads beyond its original location to other parts of the body, it is called metastatic liposarcoma. The ability of liposarcoma to spread depends significantly on its specific type or subtype. Some forms grow slowly and rarely spread, while others are aggressive and can spread early to distant organs[4][5].
Types of liposarcoma and their metastatic potential
Liposarcoma is not a single disease but rather a group of different cancers with varying behaviors and risks of spreading. Understanding which type you have is essential because it affects treatment decisions and expected outcomes[4].
Well-differentiated liposarcoma is the most common type, making up 30% to 50% of all liposarcomas. These are slow-growing tumors that typically appear in the arms, legs, or trunk. Importantly, pure well-differentiated liposarcoma is locally aggressive but does not have the ability to spread to distant parts of the body[4][5]. However, it can come back after treatment in the same area, especially when it occurs in the back of the abdomen[2].
Dedifferentiated liposarcoma can develop from well-differentiated liposarcoma and represents a more aggressive form. Unlike its counterpart, dedifferentiated liposarcoma is capable of spreading to distant sites, primarily to the lungs[5][8]. This type has a greater chance of both local recurrence and metastasis compared to other subtypes. Studies show that recurrence occurs in 40 to 75% of cases, and metastasis happens in about 10 to 15% of cases[8].
Myxoid liposarcoma and round cell liposarcoma together account for about 30% of all liposarcomas. These types usually develop in the legs and typically affect people between ages 35 and 55[4]. Myxoid liposarcoma has an unusual pattern of spread. Unlike most sarcomas that spread primarily to the lungs, myxoid liposarcoma can spread to unusual locations such as the spine, soft tissues in other parts of the body, bones including the pelvis and spine, and organs like the heart and lungs[4][6]. The metastatic potential occurs on a spectrum, with round cell features indicating more aggressive behavior[11].
Pleomorphic liposarcoma is the most aggressive subtype. It grows very fast and spreads early, with a very poor outlook for patients[4][5].
Where liposarcoma spreads
The pattern of metastasis varies significantly depending on the liposarcoma subtype. Understanding where the cancer is likely to spread helps doctors monitor patients more effectively and plan appropriate treatment[5].
For most sarcomas, including many liposarcomas, the lungs are the most common site of metastasis. About 50% of patients with high-grade soft tissue sarcomas eventually develop lung metastases, and in approximately 70% of these patients, the lungs remain the only organ with metastatic disease[19].
Dedifferentiated liposarcoma typically spreads to the lungs[5]. Recent research suggests that the spread of well-differentiated and dedifferentiated liposarcoma may be aided by tiny packages called extracellular vesicles, which contain active genetic material. These vesicles can prepare both the local tumor environment and distant sites to support tumor growth[5].
Myxoid and round cell liposarcomas show a unique metastatic pattern compared to other sarcomas. These types can spread to the spine, areas of fat tissue in the armpits and around the body, and the fat tissue at the back of the abdomen[5][6]. This unusual pattern of spread requires different monitoring strategies than for other liposarcoma types.
Outlook and survival
The outlook for patients with metastatic liposarcoma varies considerably depending on several factors, including the specific subtype, the extent of spread, and how well the cancer responds to treatment.
Overall, patients with metastasized soft tissue sarcomas generally have a difficult prognosis, with a median survival of 12 months reported in earlier studies[19]. However, more recent clinical trials have shown improved outcomes, with median overall survival reaching 16 to 17 months after systemic treatment[9].
The specific type of liposarcoma significantly impacts survival. Well-differentiated liposarcoma, which cannot spread to distant sites, generally has a good prognosis when completely removed[5]. In contrast, pleomorphic liposarcoma, which metastasizes early, has a very poor prognosis[5].
Several factors can affect how well a patient does, including the tumor’s grade (how abnormal the cancer cells look under a microscope), whether the tumor was completely removed with clear margins, the presence of metastasis, and whether the cancer has come back locally[6]. The predominant cause of death in sarcoma patients is often local recurrence rather than distant metastasis[5].
Treatment approaches for metastatic disease
Treatment for metastatic liposarcoma requires a comprehensive approach, often involving multiple types of therapy. The specific treatment plan depends on the subtype of liposarcoma, where it has spread, previous treatments received, and the patient’s overall health.
For patients with metastatic or unresectable (cannot be removed by surgery) liposarcoma, systemic therapy is the main treatment approach. Systemic therapy means treatments that travel throughout the body to reach cancer cells wherever they may be[9].
Chemotherapy remains the current mainstay of treatment for patients with metastatic or unresectable liposarcoma. The standard first-line treatment is doxorubicin, which belongs to a group of drugs called anthracyclines. Sometimes doxorubicin is combined with another chemotherapy drug called ifosfamide[9]. Adding ifosfamide can lead to higher tumor response rates and longer time before the cancer grows, but it also causes more side effects. Doctors carefully weigh the expected benefits against the anticipated side effects when deciding whether to add ifosfamide[19].
The response to chemotherapy varies among different liposarcoma subtypes. Research suggests that myxoid liposarcoma is relatively more sensitive to chemotherapy compared to other liposarcomas, particularly dedifferentiated and well-differentiated tumors. Well-differentiated liposarcoma generally shows poor response to chemotherapy[11].
Two newer drugs have been approved specifically for liposarcoma. Trabectedin was approved in November 2015 for unresectable or metastatic liposarcoma in patients who have already received an anthracycline-containing treatment. It works by binding to DNA in cancer cells. In clinical trials, trabectedin showed statistically significant improvement in preventing cancer growth compared to another chemotherapy drug, though it did not improve overall survival[11].
Eribulin was approved in January 2016 for unresectable or metastatic liposarcoma in patients who received a prior anthracycline-containing treatment. Eribulin works by interfering with structures inside cells called microtubules. In the liposarcoma subgroup of a clinical trial, results showed a 7-month improvement in survival compared to another chemotherapy drug. However, eribulin was more toxic, with side effects including low white blood cell counts, fever, nerve damage causing numbness or tingling, and hair loss[11].
In some cases, doctors may also consider radiation therapy as a valuable addition to treatment, especially for certain types like myxoid variant liposarcoma[11]. Radiation therapy in sometimes used in patients with dedifferentiated liposarcoma when the tumor was not completely removed during surgery[8].
For select patients with limited metastatic disease, particularly lung metastases, surgery to remove the metastases may be considered as part of a comprehensive treatment approach[19].
Looking toward the future, ongoing research into the distinct genetic and molecular changes in different liposarcoma subtypes has led to the development of several novel therapies. Comprehensive genetic testing of individual tumors may help guide targeted therapy for specific patients in the future[11][12].
Treatment decisions should be made through careful discussion between patients and their healthcare team, considering the specific characteristics of the cancer, the patient’s overall health and preferences, and the latest research findings.
