Understanding Multiple Myeloma Cancer

Multiple myeloma is a type of cancer of the bone marrow and blood, specifically, a malignancy of plasma cells found in the bone marrow. Bone marrow is the spongy tissue found within bones and is the site of blood production. These plasma cells are specific types of white cells called B lymphoid cells whose primary function is to secrete antibodies which help in maintaining the body's immune functions and helps prevent and fight infections. In normal circumstances, these cells cannot be detected in the peripheral blood of a healthy individual.

Multiple myeloma, also known as plasma cell myeloma, is a disease spectrum included under the broad category of heterogeneous pathologic conditions called Plasma Cell Dyscrasia (PCD). There are many other diseases included under the umbrella term of PCD, such as Monoclonal Gammopathy of Undetermined Significance (MGUS), AL Amyloidosis, Plasmacytoma, Monoclonal Gammopathy of Renal Significance (MGRS), Waldenstorms Macroglobulinemia (WM), and plasma cells leukaemia (PCL).

Multiple Myeloma Causes

Among these, multiple myeloma is one of the most prevalent diseases. It is primarily detected in the elderly population, with most cases presenting in patients above 60. In this disease, there is an uncontrolled clonal proliferation of plasma cells within the bone marrow, which starts secreting abnormal proteins or immunoglobulins (Ig), which are attempted to be removed by the kidneys. However, due to their larger size and a gradual load of these abnormal proteins, the clearance capacity of the kidneys is compromised. Eventually, they start accumulating within the kidneys causing chronic kidney damage.

Due to the proliferation of these abnormal malignant cells, the normal function of bone marrow also gradually starts getting affected, and the normal hematopoietic elements start getting suppressed. These cumulatively result in a number of haematological and biochemical changes within the body, such as anaemia (low haemoglobin), abnormal kidney function or elevated creatinine, elevated abnormal protein (called globulin), increased blood calcium level, and abnormal Ig. Their fragments are called free light chains and can be detected in the blood and urine. Due to the bones gradually losing calcium, they start getting weak and develop small breakages or lytic lesions, which can be detected by X-rays, PET scans or MRI.

Multiple Myeloma Diagnosis

Main investigations include a complete blood count, blood smear examination, kidney and liver function tests, biochemical parameters such as serum or urine protein electrophoresis, immunofixation and free light chain assays, bone marrow studies, karyotyping/ cytogenetics, next-generation sequencing (NGS), X-ray of bones or PET CT and MRI.

Multiple Myeloma Risk Factors

There are no specific risk factors for acquiring this disease. However, it occurs in a patient with a pre-existing MGUS, which is benign plasma cell dyscrasia. Hence such patients should be monitored frequently to rule out transformation to myeloma. Multiple myeloma is often associated with cytogenic or molecular abnormalities, which along with other biochemical parameters, help stratify the disease into low, intermediate or high risk, which may help decide the subsequent line of therapy.

Multiple Myeloma Symptoms

The main clinical features or symptoms in multiple myeloma will include fatigue and breathing difficulty due to low haemoglobin or anaemia, fever, a tendency to develop frequent infections as a result of low immunity, weight loss, appetite loss, bone pains usually presenting as low back pain, development of pathological fractures with minimum or no trauma, derangement of kidney function and passage of protein in the urine and features of peripheral neuropathy such as numbness, pain or tingling over the extremities. However, the diagnosis of myeloma can often be missed since most patients present with non-specific signs and symptoms, which patients may initially attribute to old age-related symptoms and may delay in seeking a medical opinion.

However, there must be a high level of suspicion for this condition to avoid misdiagnosis, which may result in disease progression and an increased likelihood for subsequent development of PCL, which is a potentially life-threatening condition.

Multiple Myeloma Treatment

The treatment of myeloma is determined by patient-related, disease-related and drug-related factors. Each patient is evaluated on an individual basis, and the appropriate line of therapy is decided by an expert group of doctors, ideally by a multi-disciplinary team approach. The treatment strategies include modalities such as Immunotherapy, Chemotherapy, Monoclonal Antibodies, Targeted therapies and Stem Cell Transplant, mainly the autologous type. However, allogeneic transplants may be used in relapsed or refractory cases in physically fit younger individuals. Moreover, CAR-T cell therapy is now an approved and promising therapeutic modality, which is a highly specialized immunotherapy involving genetically modifying a patient's T cells to attack and fight multiple myeloma.

In eligible patients, including high-risk diseases, an autologous stem cell transplant is usually recommended in keeping with the chronic relapsing nature of the disease, as this therapy may help increase the remission period and reduce the likelihood of relapses.

Conclusion

Overall, multiple myeloma is a haematological malignancy presenting in older age which is treatable via a number of modalities. With current advancements in diagnostic methods, improved individualized therapeutic regimens, better facilities and supportive care, there has been a consistent improvement in the overall survival, progression-free survival and general quality of life in patients suffering from multiple myeloma.