Marrow is the soft, spongy central portion of bones. Bone marrow consists of stem cells that give rise to the different types of blood cells. Uncontrolled proliferation of these stem cells leads to bone marrow cancer, which includes leukaemias and plasma cell neoplasms. Although leukaemias can affect individuals of any age, it is the most common cancer in children. Per statistics, in adults, leukaemia affects individuals above 55 years of age, while in children it is observed in those below 15 years.
Leukaemia may be acute or chronic, and prognosis/overall survival rate depends upon the type of disease. White blood cells are commonly affected in leukaemia. On the other hand, plasma cell neoplasm affects the plasma cells- blood cells that make antibodies to fight infections. There are several types of plasma cell neoplasms namely Monoclonal gammopathy of undetermined significance (MGUS), Plasmacytoma, Multiple myelomas. One interesting aspect of plasma cell neoplasms is that it may be benign or malignant.
MGUS is a benign form, wherein less than 10% of the bone marrow is made up of abnormal plasma cells. In this condition, there is the production of M protein, an antibody not required by the body to fight infections, which accumulates in the marrow causing blood to thicken and ultimately damage the kidneys.
If detected at an early stage, this condition is treatable and is associated with good prognosis. Multiple myelomas are considered relatively more serious as it prevents the formation of healthy blood cells. Moreover, tumours may form in several bones in the body, causing generalized symptoms. As the stage of multiple myeloma advances, production of all blood cells- RBCs, WBCs, and platelets is affected. This results in reduced oxygen supply to tissues and organs, predisposition to infections, and increased tendency to bleed.
The chief concern with plasma cell neoplasms is that they result in amyloidosis, which refers to the accumulation of protein in various organs of the body. Prognosis depends on the type of plasma cell neoplasm, stage of the disease, presence of a certain immunoglobulin (antibody), genetic changes, and extent of kidney damage.
It is important to consider the response of the cancers to treatment and recurrence, as this determines the outcome of subsequent treatments. Concerning the life expectancy of individuals suffering from bone marrow cancer, recent studies have reported that the 5-year survival rate for leukaemia is 61.4%. Owing to advances in treatment and absence of co-morbid conditions, the survival rate is higher in young patients.
- In contrast, plasma cell neoplasms (especially multiple myeloma) is not considered “curable,” as the symptoms tend to wax and wane with time. These neoplasms are associated with recurrence; however, the period of dormancy of cancer may last for years.
- As previously mentioned, the time of diagnosis and stage of the condition play a major role in determining the outcomes. Early stages of multiple myeloma are associated with approximately 5 years survival rate, whereas advanced stage/stage 3 is associated with 2-3 years survival. Please bear in mind that survival rates are calculated from the time treatments to begin; therefore, may differ in each individual.
- Nonetheless, with rapid advances in screening, diagnosis, as well as novel therapeutic approaches, individuals with cancers of the bone marrow now live longer with a lower rate of side effects and improved quality of life.
(Inputs by Dr Pradeep Mahajan, Regenerative Medicine Researcher)
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