What is blood cancer?
A cancer that affects the production and function of blood cells. Most of these cancers start in bone marrow, where blood is produced. In most blood cancers, the normal blood cell development process is interrupted by uncontrolled growth of an abnormal type of blood cell. These abnormal blood cells, or cancerous cells, prevent blood from performing its functions resulting into serious infections, bleeding and/or anemia.
Burden of blood cancer in India
India has witnessed rising growth of cancer cases including blood cancer in the last decade, this has become a major public health concern for this developing nation. As per Globocon 2018 data, about 1 lakh patients were diagnosed with blood cancer in India in 2018. Studies suggest that India ranks third highest in incidence of blood cancer after US and China.
What causes blood cancer?
No causative factor is established yet but some risk factors have close link to blood cancer like ionizing radiation, past history of treatment with certain chemotherapeutic agents, some viruses and genetic condition like Down’s syndrome.
Types of blood cancer
There are three main types of blood cancers: Leukemia, Lymphoma and Myeloma.
There are different types of leukemia. Some types grow slowly (Chronic Leukemias), while others grow much faster (Acute Leukemias)
What are the symptoms of leukemia?
Feeling very tired and weak (anemia)
Bleeding more easily than normal (low platelets)
Getting sick from infections more easily than normal (low WBC)
What are the tests for leukemia?
Blood tests- Complete blood count with peripheral smear (Figure 1)
Bone marrow aspiration and biopsy
Some special and molecular tests like Immunophenotyping, Cytogenetics and FISH studies etc according to the type of cancer
How is leukemia treated?
Acute leukemias are treated right away on urgent basis. Some chronic leukemias might need only single oral drug and even some which are slow-growing and not causing symptoms, close monitoring is done until treatment is needed.
Treatment for leukemia can include combination of one or more of the following:
Chemotherapy, Targeted therapy, Radiation therapy and Bone marrow transplant depending on the type of leukemia, age and co-morbidities of patient.
Revolution in the treatment of blood cancers:
Revolution in treatment of ALL (Acute Lymphoblastic leukemia)
Before 1960s, there was hardly any treatment available for ALL (Acute Lymphoblastic leukemia) – a type of leukemia more common in children and young adults, due to which most of patients of ALL used to die. Currently, with the availability of better multi-drug regimens and diagnostic modalities and with better understanding of the disease, the survival of ALL has reached upto more than 90 percent specially in pediatric age group. (Figure 2)
Minimal Residual Disease (MRD) testing is now changing the treatment paradigm in ALL
MRD testing with latest techniques like multicolor flow cytometry is prognostic as well as it guides for further decision making whether to go for stem cell transplant or not and for escalation and de-escalation of treatment.
Revolution in treatment of chronic myeloid leukemia (CML)
In 2001, the advent of imatinib- a Tyrosine Kinase Inhibitor (TKI) in CML revolutionized the field of oncology with the new concept of targeted therapy/precision medicine- that can selectively kill the cancer cells but leave the healthy cells intact. It has immensely changed the outcome that it took the once dying patients out of bed and made them do their routine chores with a single oral pill.
Other revolutions in blood cancer treatment
The revolution is ongoing with more and more targeted therapies being available in blood cancers now like second generation TKIs in CML, Ibrutinib in CLL; Daratumubab, Elotuzumab in multiple myeloma; Rituximab and Obinituzumab in NHL and newer therapies like CAR-T cell in ALL. The list is very long including the recent advances in stem cell transplant and the numbers in list are increasing day by day.
Still a wide gap remains…
While we have gained more knowledge and expertise in treating and dealing with blood malignancies, we have our own challenges specific to a developing country due to lack of sensitization for each symptom, lack of awareness and education as well as lack of holistic and affordable health care, especially in rural areas.
Minimizing the gap with good team work involving patient‘s family, physicians, pediatricians, hemato-oncologist, radiation oncologist and pathologist can make the unbeatable a beatable one.