Acute leukemia is an aggressive condition that needs rapid diagnosis and treatment within a few days after detection.
Usually a multi-disciplinary team is employed to treat ALL. The team includes:
- an oncologist (cancer specialist)
- an haematologist (one who specializes in blood and related disorders)
- a pathologist
- a radiotherapist
- a neurologist (if there is involvement of the central nervous system)
- a paediatrician (childhood disease specialists since ALL is common among children)
- a social worker
- a clinical oncology nurse
- a counsellor
Three phases of treatment
Treatment is given in three main phases. These include:-
- Induction – this forms the initial phase of treatment and is employed to kill the leukaemia cells within the bone marrow. This helps the cells of the blood to normalize and relives symptoms of the cancer.
- Consolidation – this phase kills the remaining leukemia cells that have remained after an aggressive induction phase.
- Maintenance – this is the final phase that involves regular chemotherapy pills to be taken orally to prevent a relapse of the leukemia. Maintenance phase is effective only in ALL and is not used in AML.
Therapy used in Induction phase
The induction stage of treatment is provided in a hospital set up. Usually a combination of oral and intravenous chemotherapy drugs are administered. These drugs carry the risk of lowering blood counts further and more severely. This may lead to severe anemia, infections and risk of uncontrolled bleeding.
Patients may require blood transfusions and supportive therapy to combat these severe side effects of the chemotherapy drugs.
More than one chemotherapy agent is used in the induction phase. The most commonly used drugs include:-
- Vincristine (Oncovin®)
- Daunorubicin (daunomycin or Cerubidine®) or doxorubicin (Adriamycin®)
- Cytarabine (cytosine arabinoside, ara-C, or Cytosar®)
- L-asparaginase or PEG-L-asparaginase
- Etoposide (VP-16)
- 6-mercaptopurine (6-MP)
- Dexamethasone etc.
An intravenous tube may be inserted into a large vein near the heart to deliver the chemotherapy drugs. This is known as a central line. This reduces the number of painful injections.
Chemotherapy may also be administered into the spine and cerebrospinal fluid using lumbar puncture. This is used in patients in whom the cancer has spread to the central nervous system.
Chemotherapy leads to several other side effects that resolve on completion of therapy. This includes nausea, vomiting, diarrhea, loss of appetite, mouth sores, fatigue, rashes, hair loss etc.
These are agents that can be used in selected patients with specific cytogentic patterns.
For example, in patients with the Philadelphia chromosome (t9:22), agents called tyrosine kinase inhibitors like Imatinib may help. Imatinib works by blocking signals that tell the cancer cells to grow. Imatinib may be taken orally.
Other agents include Dasatinib, Nilotinib etc.
Therapy used in Consolidation phase
After removal of the majority of cancer cells from the body in the induction phase, the consolidation phase is started. The aim of this phase is to remove and kill any residual cancer cell within the body.
Treatment involves receiving regular injections of chemotherapy medication. Unlike induction phase, this phase can be conducted on an outpatient or daycare basis. This phase may last several months.
Therapy used in the maintenance phase
The maintenance phase aims to prevent the cancer from returning. It involves taking regular doses of chemotherapy tablets along with regular follow ups and check-ups. The maintenance phase can often last for two years.
Other treatments that may be used in ALL:-
- Radiation therapy – radiotherapy may be used in some special cases of ALL. It helps in killing off the cancer cells. It is useful in advanced cases of ALL that has spread to the brain or central nervous system or before a bone marrow transplant.
- Bone marrow and stem cell transplants – the introduction of bone marrow and stem cell transplants have revolutionized treatment of leukemias like ALL. The treatment basically involves use of very high dose aggressive chemotherapy to kill of all the cancer cells and some of the healthy cells of the bone marrow. Following this healthy bone marrow or stem cells are transfused to replace the destroyed cells of the bone marrow.
The fresh marrow that replaces the destroyed cancerous bone marrow can be taken from the patient himself/herself (in case of an autologous bome marrow transplant) or from a related and genetically matched donor. The best candidate to provide a donation is usually a brother or sister with the same tissue type.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)