Multiple Myeloma Flashcards
(42 cards)
Multiple myeloma refers to a malignant disorder of … (mature B lymphocytes).
Multiple myeloma refers to a malignant disorder of plasma cells (mature B lymphocytes).
… is the second most common haematological malignancy. It is characterised by excess secretion of a monoclonal antibody. We term it a monoclonal antibody, because it is derived from a single clone of plasma cells that have undergone abnormal proliferation.
Multiple myeloma (MM) is the second most common haematological malignancy. It is characterised by excess secretion of a monoclonal antibody. We term it a monoclonal antibody, because it is derived from a single clone of plasma cells that have undergone abnormal proliferation.
MM accounts for 60-70 cases per 1,000,000 people each year, although the overall prevalence of the condition is increasing due to the improved survival with newer treatments. Unfortunately, it still accounts for 2% of cancer-related deaths and it is associated with a number of severe complications including spinal cord compression, renal impairment and hypercalcaemia,
MM accounts for 60-70 cases per 1,000,000 people each year, although the overall prevalence of the condition is increasing due to the improved survival with newer treatments. Unfortunately, it still accounts for 2% of cancer-related deaths and it is associated with a number of severe complications including spinal cord compression, renal impairment and hypercalcaemia,
severe complications of multiple myeloma
including spinal cord compression, renal impairment and hypercalcaemia
The pathophysiology of MM is still poorly understood but there appears to be a two-step model.
Development of MGUS: almost all cases of MM arise from this premalignant plasma cell disorder. Affects 3% of patients > 50 years old. Initial cytogenetic abnormality occurs (inciting event). Thought to be an abnormal plasma cell response to antigen stimulus. Leads to creation of plasma cell clone that secretes a monoclonal antibody. Most will not develop MM.
Progression from MGUS to MM: rate of progression estimated at 1% per year. Further cytogenetic abnormalities and changes to the bone marrow microenvironment occur, which promotes proliferation. Associated with systemic problems due to plasma cell infiltration of bone marrow and excess light chain secretion.
Clinical presentations
The clinical presentation of MM is generally related to the infiltration of plasma cells and secretion of monoclonal antibodies.
Patients with MM may have constitutional features of malignancy including weight loss, fatigue, loss of appetite and/or generalised weakness. There are a number of typical clinical presentations that relate to the excess proliferation and infiltration of plasma cells (usually in bone marrow) and the excess secretion of monoclonal antibodies.
Presenting clinical features of multiple myeloma
Bone disease: widespread due to clonal proliferation in bone marrow. Seen as lytic lesions on imaging. Can lead to fractures.
Impaired renal function: >50% have raised creatinine at diagnosis. Kidneys affected in multiple ways. Commonly due to light chain nephropathy (tubules blocked by light chain casts).
Anaemia: seen in >90% at some point during disease course. Normal bone marrow destroyed by proliferation of malignant plasma cells. Renal disease may contribute (EPO deficiency).
Hypercalcaemia: MM-induced bone demineralisation. More common in active disease. At high levels (≥ 2.9 mmol/L) should be treated as a medical emergency. See our notes on hypercalcaemia.
Recurrent or persistent bacterial infection: immune dysfunction and hypogammaglobulinaemia due to suppression of normal plasma cell function.
CRAB
C - calcium levels high
R - renal impairment
A - anaemia
B - bone disease
What condition?
Multiple myeloma
MM can present with a myriad of other clinical features, some presenting as medical emergencies. These may include …, fever (<1%), splenomegaly (1%), … (4%) or lymphadenopathy (1%). Neurological involvement can result from hyperviscosity syndromes, spinal cord compression, peripheral neuropathy or radiculopathy.
MM can present with a myriad of other clinical features, some presenting as medical emergencies. These may include paraesthesia, fever (<1%), splenomegaly (1%), hepatomegaly (4%) or lymphadenopathy (1%). Neurological involvement can result from hyperviscosity syndromes, spinal cord compression, peripheral neuropathy or radiculopathy.
Hyperviscosity syndrome: may develop with high paraprotein levels (i.e. high IgA or IgG). Typical symptoms include blurred vision, headaches, mucosal bleeding and dyspnoea due to heart failure. Requires urgent…
Hyperviscosity syndrome: may develop with high paraprotein levels (i.e. high IgA or IgG). Typical symptoms include blurred vision, headaches, mucosal bleeding and dyspnoea due to heart failure. Requires urgent plasma exchange.
Spinal cord compression: can occur in 5% of patients during course of disease of..
Spinal cord compression: can occur in 5% of patients during course of disease. Highly variable depending on lesion causing compression, location, and rate of development. See our notes on cord compression.
Multiple myeloma
Myeloma should be suspected in any patient with typical features, but particularly those over 60 years old with:
Unexplained bone pain (and pathological fractures)
Fatigue
Symptoms of hypercalcaemia: bone pain, abdo pain, constipation, confusion, polyuria
Weight loss
Symptoms of cord compression: back pain, new leg weakness, bladder/bowel dysfunction
Symptoms of hyperviscosity: headache, blurred vision, shortness of breath, mucosal bleeding
Recurrent infections
Those over 60 with these symptoms should be screened/suspected for …
Unexplained bone pain (and pathological fractures)
Fatigue
Symptoms of hypercalcaemia: bone pain, abdo pain, constipation, confusion, polyuria
Weight loss
Symptoms of cord compression: back pain, new leg weakness, bladder/bowel dysfunction
Symptoms of hyperviscosity: headache, blurred vision, shortness of breath, mucosal bleeding
Recurrent infections
Multiple myeloma
‘Screening’ for myeloma involves looking for …, which are the secretion product of the malignant clones.
‘Screening’ for myeloma involves looking for monoclonal antibodies, which are the secretion product of the malignant clones.
When we ‘screen’ for myeloma we are looking for the secretion product of the malignant clone of plasma cells - the monoclonal antibodies. We can do this using… and ….
When we ‘screen’ for myeloma we are looking for the secretion product of the malignant clone of plasma cells - the monoclonal antibodies. We can do this using protein electrophoresis and immunofixation. Electrophoresis tells us whether there is an increased number of antibodies. This is followed by immunofixation, which tells us what type of antibody has increased (i.e. is it a monoclonal antibody). MM is usually the result of IgG, IgA or the accompanying light chain. It rarely occurs with IgM.
NOTE: The presence of an … monoclonal antibody suggests another haematological malignancy termed Waldenstrom macroglobulinemia.
NOTE: The presence of an IgM monoclonal antibody suggests another haematological malignancy termed Waldenstrom macroglobulinemia.
Protein electrophoresis
This is a quantitative test that separates proteins into different bands using an electric current. The distance individual proteins travel is dependent on their shape, size and electrical charge. Electrophoresis gives us characteristic band patterns including normal, polyclonal and monoclonal.
Immunofixation is a qualitative test that ‘fixes’ proteins in place by using antibodies. It is important for the identification of proteins after separation by electrophoresis.
Urine electrophoresis and serum free light chains
Protein electrophoresis assumes that all myelomas secrete an intact antibody. In fact, around 20% of myelomas only secrete light chains. To help detect these myelomas we can send off serum free light chains (SFLCs) or urine for electrophoresis.
SFLCs is a newer test that looks at the amount of light chain unbound to heavy chains within the blood. Light chains are secreted in healthy individuals as plasma cells produce more light chains than heavy chains. Therefore, it is the ratio between the light chains kappa and lambda, which is the most important factor. An elevated ratio is suggestive of myeloma and needs further work-up.
Alternatively, a urine electrophoresis can be completed. Light chains within the serum may be filtered by the kidneys into the urine. Monoclonal light chains detected in the urine are known as Bence-Jones proteins. NICE recommend the use of serum protein electrophoresis and SFLCs in the work-up of suspected myeloma. Depending on the centre, urine electrophoresis may still be used in combination with the above two tests or as an alternative to SFLCs.
Diagnosis of MM involves identifying a … antibody, … analysis and assessing organ damage.
Diagnosis of MM involves identifying a monoclonal antibody, bone marrow analysis and assessing organ damage.
Diagnostic criteria
Diagnosis of MM involves identifying a monoclonal antibody, bone marrow analysis and assessing organ damage.
The work-up and diagnosis of MM is dependent on identification of a monoclonal antibody (sometimes referred to as M protein or paraprotein), analysis of the bone marrow to look for a population of malignant clonal plasma cells and further laboratory tests and imaging to assess for myeloma-related organ damage.
Monoclonal antibody detection: protein electrophoresis & immunoglobulins, SFLCs +/- urine electrophoresis for Bence-Jones protein
Bone marrow infiltration: bone marrow aspirate and trephine with cytogenetics
Myeloma-related organ damage: FBC, U&Es, bone profile, imaging (whole body MRI or low-dose whole body CT if MRI not suitable). Skeletal survey (x-rays) only used if CT/MRI not possible
Staging if confirmed myeloma: beta-2 microglobulin, albumin
Treatment in multiple myeloma
MM is an incurable condition, treatments aim to increase periods of disease remission.
Myeloma - is it curable?
There are many options for the treatment of myeloma. Management depends on a patients fitness and co-morbidities, disease severity, initial response to treatment, relapse(s) and previous therapy. All patients should be discussed in an MDT specialising in myeloma and have access to psychological services, palliative care and support, specialist nurses and clinical research.
Unfortunately, there is no cure for myeloma. The aim is to induce disease remission and then maintain disease free survival for as long as possible with ongoing monitoring for disease relapse. The four key areas of management include: induction therapy, autologous stem cell transplantation (ASCT), maintenance therapy and managing relapse or refractory disease.