Chemotherapy is the use of drugs to kill cancer cells. Unlike ]]>radiation]]> and surgery, which are localized treatments, chemotherapy is a systemic treatment, meaning the drugs travel throughout the entire body. This means chemotherapy may reach every cell in the body.

Many people with MDS do not require chemotherapy treatment other than supportive treatments such as intermittent transfusions. However, at times chemotherapy may be required if no other options exist.

Chemotherapy Drugs Used for MDS

Standard Chemotherapy

There are three combinations of chemotherapy drugs used to treat MDS. These combinations include:

Hypomethylating Agents

Hypomethylating agents are drugs that slow down the growth of cells, and include:

Immunomodulating Therapy

Immunomodulating drugs change the immune system, and include:

Immunosuppression Agents

Immunosupression agents suppress the immune system, and include:

These agents have been used alone, in combination with other anticancer drugs, and with drugs in other categories, such as hematopoietic growth factors.

Thalidomide was initially used to treat MDS but has been replaced with lenalidomide (Revlimid) because of fewer side effects. Lenalidomide has been successful in reducing the number of transfusions needed by patients with low-grade MDS.

Effectiveness of Chemotherapy

A number of anti-leukemia chemotherapy regimens have induced short-term remissions in as many as 60% of people with MDS, but at substantial risk. The length of these intensive treatment regimens may run between six and nine months. Aggressive anti-leukemia treatment schedules produce a mortality rate up to 30%. Less aggressive programs are suitable for some patients, but again the responses are brief.

The only cure for MDS is a ]]>stem cell transplant (SCT)]]>. A SCT starts with high-dose ]]>chemotherapy]]> to kill the bone marrow, and is then followed by an injection of healthy stem cells. The stem cells used can come from the blood or bone marrow.

There are two types of SCT. The less common one is called an autologous SCT, and occurs when the patient is injected with his or her own cells after high-dose chemotherapy. The more common method is called allogeneic and occurs when the patient gets donor cells after high-dose chemotherapy.

Low-dose chemotherapy treatment may briefly benefit certain classes of patients, such as the elderly, by exposing them to lower risk.

Side Effects and Possible Complications

Side effects of chemotherapy for MDS are identical to those seen in ]]>leukemia]]> and other forms of ]]>cancer]]> . The only unique aspect of treating MDS is the advanced age of the patients, which makes many side effects more likely and more dangerous.