Dermatofibrosarcoma protuberans (DFSP): Diagnosis and treatment
How do dermatologists diagnose dermatofibrosarcoma protuberans (DFSP)?
Your dermatologist will closely examine your skin. If your dermatologist suspects you have DFSP, you will need a skin biopsy. This is the only way to diagnose skin cancer. Your dermatologist can safely perform a skin biopsy during an office visit.
To perform a skin biopsy, your dermatologist will remove some of the tumor. What your dermatologist removes will be examined under a microscope. This magnified view allows a doctor to look for cancer cells.
Sometimes, a second skin biopsy is necessary to diagnose DFSP.
How do dermatologists treat DFSP?
If the diagnosis is DFSP, you will need a thorough physical exam. You may also need some medical tests. These tests provide the information necessary to create a treatment plan for DFSP.
Your dermatologist may create the treatment plan. Sometimes, doctors from different medical specialties team up to create the treatment plan. The doctors may include a dermatologist, surgical oncologist (cancer specialist), and plastic surgeon.
Most treatment plans include surgery to remove the cancer. Because DFSP can grow deep, other treatment may be necessary. A treatment plan for DFSP usually includes one of more of the following treatments:
Excision (surgery): During this surgery, the surgeon removes the tumor(s) and some surrounding tissue that looks healthy. Removing this tissue helps to catch cancer that may have traveled to an area that still looks healthy.
Mohs surgery: For many DFSP patients, Mohs (pronounced "Moes") surgery may be recommended. This specialized surgery is only used to treat skin cancer. This surgery allows the Mohs surgeon to remove less tissue than is removed during excision (the surgery described above.)
During Mohs surgery, the Mohs surgeon cuts out the tumor plus a very small amount of healthy-looking tissue surrounding the tumor. While the patient waits, the Mohs surgeon uses a microscope to look at what was removed. The surgeon is looking for cancer cells.
If the Mohs surgeon finds cancer cells at the edge of the removed tissue, the surgeon will remove another small amount of tissue and look at it under the microscope. This process continues until the surgeon no longer sees cancer cells along the edge of the removed tissue. Your Mohs surgeon may refer to this edge as the “margin.” When the Mohs surgeon no longer sees cancer cells along the edges, the surgeon may tell you that the “margins look clear.”
Reducing the risk of DFSP returning
When DFSP grows into the lower layer of skin, the cancer often spreads out like the roots of a plant. This root-like growth can make it difficult to remove all of the cancer.
To reduce the risk of DFSP returning after surgery, your dermatologist may include a second treatment. The second treatment helps to kill cancer cells.
Dermatologists also are studying new treatment options. One way to reduce DFSP from returning may be to treat patients with both excision and Mohs surgery. In one small study, the cancer did not return when patients received both excision and Mohs.
More research is needed to find out whether this can reduce the risk of DFSP returning.
Reconstructive surgery: DFSP can grow deep, so some patients need reconstructive surgery to repair the wound caused by the surgery.
Radiation treatments: After surgery, some patients receive radiation treatments. These treatments can destroy cancer cells. Because of the long-term risks involved in getting radiation treatments, doctors carefully consider the benefits and the risks of this treatment.
The results from a small study show that radiation may reduce the risk of DFSP from returning. Researchers followed 14 patients who received radiation treatments, mostly after surgery. Most patients, 86%, remained cancer-free. The average follow-up period exceeded 10 years.
When surgery is not possible
Some patients cannot undergo surgery. When this happens, other treatment options are used. Some patients have radiation treatments. Other options include:
Imatinib mesylate: This is a chemotherapy medicine. The U.S. Food and Drug Administration (FDA) has approved this medicine to treat DFSP in adults when the cancer:
- Cannot be treated with surgery.
- Returns after treatment.
- Has spread to other parts of the body.
Some chemotherapy medicines kill both cancerous and healthy cells. Imatinib mesylate works differently. It is designed to target specific cancer-causing molecules. This gives it the power to kill cancer cells while preventing serious damage to non-cancerous cells.
This medicine is not right for every patient who has DFSP. For this medicine to work, patients must have certain DNA. Testing is required to find out whether a patient has that DNA.
If your doctor prescribes imatinib mesylate, you will need to be carefully supervised.
After taking imatinib mesylate, some patients are able to have surgery because the drug shrinks the DFSP enough so that the cancer can be surgically removed.
Clinical trial: Some patients are encouraged to join a clinical trial. A clinical trial is a type of research study. This study tests how well new a treatment or a new way of treating a disease works. For some patients, joining a clinical trial may be the best treatment option.
What is the outcome (prognosis) for patients with DFSP?
This skin cancer rarely spreads to other parts of the body, so people often live for many years after treatment.
Lifelong follow-up with your doctors is essential though. DFSP can return after treatment. If DFSP returns, it is often treated with one of the surgeries described above. Some patients receive radiation treatments after surgery. Taking the drug imatinib mesylate may be an option for some patients.
It is very important to keep all follow-up appointments.
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