Acute Lymphocytic Leukemia

 Acute lymphoblastic leukemia, also known as acute lymphocytic leukemia or acute lymphoid leukemia (ALL), is an acute form ofleukemia, or cancer of the white blood cells, characterized by the overproduction and accumulation of cancerous, immature white blood cells, known as lymphoblasts.

ALL, lymphoblasts are overproduced in the bone marrow and continuously multiply, causing damage and death by inhibiting the production of normal cells (such as red and white blood cells and platelets) in the bone marrow and by spreading (infiltrating) to other organs. ALL is most common in childhood, with a peak incidence at 2–5 years of age and another peak in old age.

The signs and symptoms of ALL are

• Generalized weakness and fatigue

• Bone pain, joint pain (caused by the spread of "blast" cells to the surface of the bone or into the joint from the marrow cavity)

• Breathlessness

• Enlarged lymph nodes, liver and/or spleen

• Pitting edema (swelling) in the lower limbs and/or abdomen

• Petechiae, which are tiny red spots or lines in the skin due to low platelet levels

Tests and Diagnosis

• Physical examination

• Complete blood count

• Blood smear

• Bone marrow biopsy

• Spinal tap

 Treatment and Medication

Chemotherapy

Remission induction: Combination of prednisolone or dexamethasone, vincristine, asparaginase (better tolerance in pediatric patients), and daunorubicin (used in Adult ALL) is used to induce remission. Central nervous system prophylaxis can be achieved via irradiation, cytarabine and methotrexate, or liposomal cytarabine.In Philadelphia chromosome-positive ALL, the intensity of initial induction treatment may be less than has been traditionally given.

Consolidation: Typical consolidiation protocols use vincristine, cyclophosphamide, cytarabine, daunorubicin, etoposide, thioguanine or mercaptopurine given as blocks in different combinations. For CNS protection, intrathecal methotrexate or cytarabine is usually used combined with or without cranio-spinal irradiation (the use of radiation therapy to the head and spine). Central nervous system relapse is treated with intrathecal administration of hydrocortisone, methotrexate, and cytarabine.

Maintenance therapy: oral mercaptopurine, once weekly oral methotrexate, once monthly 5-day course of intravenous vincristine and oral corticosteroids are usually used. The length of maintenance therapy is 3 years for boys, 2 years for girls and adults.

And the other include

Immunotherapy: Chimeric antigen receptors (CARs) have been developed as a promising therapy for ALL. This technology uses a single chain variable fragment (scFv) designed to recognize the cell surface marker CD19 as a method of treating ALL. CD19 is a molecule found on all B-cells and can be used as a means of distinguishing the potentially malignant B-cell population in the patient.

Biological therapy: ALL, aiming at biological targets such as the proteasome, in combination with chemotherapy, has given promising results in clinical trials.Selection of biological targets on the basis of their combinatorial effects on the leukemic lymphoblasts can lead to clinical trials for improvement in the effects of all treatments.

Radiation therapy: Radiation therapy (or radiotherapy) is used on painful bony areas, in high disease burdens, or as part of the preparations for a bone marrow transplant.

 Statistics

Within a population of 882 million, six thousand children will develop acute lymphoblastic leukemia each year in India. These children come from three socio-economic backgrounds: Profile I (70%) being extremely poor who cannot afford any treatment unless it is provided free, Profile II (25%) from the middle class, and Profile III (5%) who can afford to have the best possible treatment.

Current protocols for childhood ALL range from simple low-cost regimes like UKALL VIII, intermediate intensity regimes like BFM 76/79, and aggressive regimes aimed at increasing cure rates in the high risk groups. Since state resources are limited, the pediatric oncologist in India has to decide on the appropriate treatment protocol for the individual child in each of these profiles.