Blood cancer treatment and its side effects

Blood cancers also known as Leukemia, occur in the bone marrow which is the production house of blood in our body. Blood cancer occurs due to the growth of abnormal blood cells in our body. These abnormal cells are cancerous and lead to excessive production of white blood cells in the body which leads to the symptoms.

Around 1 Lakh people are diagnosed with blood cancers in India out of which around 20,000 occur in children themselves. Any age group can be affected starting from pediatric to geriatric. Acute Leukemias are more common in the pediatric age group compared to chronic Leukemia which is more common in adulthood.

Nobody knows what causes leukaemia. But. it is caused by certain unusual chromosomes, but the chromosomes do not cause leukaemia. Leukaemia cannot be prevented, but certain factors can set it off. Though, some people who are addicted might be at a greater risk of contracting the disease. Those who are addicted to smoking, who get exposed to a lot of radiation or certain chemicals, have received radiation therapy or chemotherapy to treat cancer, have a family history of leukaemia, have a genetic defect, like Down syndrome.

Blood cancers can be diagnosed by a simple complete blood count and peripheral smear examination however, bone marrow evaluation is required to confirm the subtype of Leukemia. Along with bone marrow evaluation, a Cerebrospinal fluid examination is required to determine whether the leukaemia has spread to the central nervous system or not.

The treatment depends upon the type of Leukemia. For example, in acute lymphoblastic leukaemia (ALL) the treatment in children usually consists of 3 phases of therapy Induction that usually lasts for 1 month, consolidation that lasts for about 5-6 months and maintenance that lasts for a total duration of 2 years. Similarly, the treatment of Acute Myeloid Leukemia also spans for approximately about 4-5 months duration.

The treatment of cancers generally requires multimodality therapy which includes chemotherapy, radiotherapy, surgery, stem cell transplant, and in recent years Immunotherapy and cell therapies. Generally, most patients require chemotherapy alone with only a small percentage requiring radiotherapy to prevent central nervous system leukaemia. Stem cell transplant is a type of therapy where high dose chemotherapy is given to remove the tumour cells and later stem cells are infused from self (auto) or from a donor (allo) to recover the blood cells. Stem cell transplant is indicated in many types of acute myeloid Leukemia and relapsed Leukemias.

In recent years Immunotherapy and cell therapies have shown to be very promising and are likely to replace chemotherapy in the next two decades.

Patients who undergo these therapies also suffer from various side effects. The side effects of blood cancer treatment could be classified into Acute (on treatment) or late (after treatment). Acute Side effects are mostly due to the ongoing therapy and are secondary to chemotherapy administration which includes nausea and vomiting, fever, hyperglycemia and hypertension, thrombosis, bleeding, extravasation, mucositis, and constipation or diarrhoea.

Late side effects usually occur once the therapy has been completed and are again secondary to the treatment given. Late effects include Cardiomyopathy secondary to chemotherapy agent (Anthracycline), Second malignancies Neurocognitive impairment (If cranial Radiotherapy is used), and Metabolic syndrome.

(Both the authors work at Kasturba Medical College, Manipal. While Dr Vasudeva Bhat K is Associate Professor and In-charge Head, Division of Paediatric Hematology & Oncology, Dr Karthik Udupa is Professor and HOD, Department of Medical Oncology)