Liposarcoma - A Primer

Updated March 2016

It was just announced that Rob Ford passed away after being diagnosed with liposarcoma 18 months ago.  My sympathies to his family.

Liposarcomas are a malignancy of fat cells.  They normally appear as a slowly enlarging, relatively painless mass.  Liposarcomas are a relatively rare form of cancer that affects connective tissues in the body and account for 18 percent of all soft-tissue sarcomas.  They can occur throughout the body but around one-third are found in the abdominal cavity and half occur in the thigh.  Tumours in the abdomen are more difficult to find, meaning that they can grow to a larger size before they become symptomatic.  This type of cancer tends to affect adults between the ages of 40 and 60 years with a mean onset age of 50 years..

There are four types of liposarcoma:

1   Well-differentiated liposarcoma is the most common subtype and usually starts as a low grade tumor. Low grade tumor cells look much like normal fat cells under the microscope and tend to grow and change slowly.  This type tends to occur in arms, back, legs or abdomen.

2   Myxoid liposarcoma is an intermediate to high grade tumor. Its cells look less normal under the microscope and may have a high grade component.  This type metastasizes to bones, lungs, brain and liver.

3   Pleomorphic liposarcoma is the rarest subtype and is a high grade tumor with cells that look very different from normal cells.

4   Dedifferentiated liposarcoma occurs when a low grade tumor changes, and the newer cells in the tumor are high grade.

Tumours with a higher grade are more difficult to treat and the risk of metastasis (spreading) and recurrence rises.  From what Mr. Ford's physician said this about this case, Mr. Ford's liposarcoma is of the pleomorphic type.

Here is a photo of a liposarcoma that has been surgically removed:

Surgery and radiation are commonly used in combination and are quite successful at preventing recurrence.  

The five-year survival rates for liposarcoma are as follows:

Well-differentiated liposarcoma - 100 percent

Myxoid liposarcoma - 88 percent

Pleomorphic lipsarcoma - 56 percent.

Because pleomorphic liposarcoma is relatively rare, there have been limited studies with long-term followup information.  Approximately 5000 patients in the United States are diagnosed with soft tissue sarcomas every year with an average annual incidence of 2.5 cases per million persons.  This type of cancer is somewhat more common in men than in women and there is no association with race or geography.  According to the Mount Sinai website, risk factors that can increase one's risk for getting soft tissue sarcomas are:

Exposure to dioxin

Exposure to chemicals in herbicides and wood preservatives

Exposure to radiation

Weakened immune system (i.e. HIV)

Having lost my father to cancer relatively recently, I can only imagine what the Ford family has gone through over the year and a half.

  

References:

Medscape

Sarcomahelp

Nature