Multiple Myeloma - What is it all about?

I read a very helpful book called Multiple Myeloma - The Plain English Handbook for Patients and Care Givers written by Robert J. Heller who was a care giver to his wife.

I thought I would quote some of his explanations as they have helped me understand Multiple Myeloma a little better in layman's terms.  I hope it will help you too.


What is it all about?

MM is not an easy disease to understand.  The most basic definition is that it is a process in which deformed blood cells start to multiply without any control on their reproduction.  These cells generally inhabit the bones of the patient where their presence causes damage.  As they grow they play vampire and need to suck your blood to stay alive.  To do so they start to create new blood supply lines, which you don't need.

The effect of this overgrowth plus the creation of new small blood vessels in the bones starts to break down the bones themselves.  As the bones break down, calcium is released into the blood stream and your kidneys attempt to get rid of as much of it as they can, along with excess protein.  

This over-simplification of the process of MM is not the complete story by any means.  There are various types of myeloma and they range from a myeloma which required no treatment other than careful monitoring, to the most severe which requires dramatic and immediate intervention.

You will hear the doctors often refer to a MM Stage.  There is a classification table developed that is commonly used to classify patients.  Stage-1 refers to patients with a low cell mass of myeloma cells and who have a haemoglobin value greater than 10, with calcium values equal to or less than 12 milligrammes per decilitre, with fewer that two or no malignant bone tumours, and a low production rate of M protein.

Jumping ahead to Stage-3, that is defined as patients who have a much higher myeloma cell mass and in addition to all of the conditions defining Stage-1 also have ONE or more of these symptoms; haemoglobin value less that 8.5, calcium value more than 12, advanced lytic bone lesions (tumours), or a high M protein production rate.

And Stage-2 basically defined as patients who exhibit some symptoms but who don't fall specifically into Stages 1 or 3, but whose myeloma cell mass is in the mid-range.

You will hear of MM referred to by Classification as well as Staging.  The least destructive situation is one in which you have been diagnosed with monoclonal gammopathy of undetermined significance (MGUS) and this is a situation where some monoclonal cells are determined to be present but there are no other symptoms and no treatment is indicated at the time.  That's the good news.  However, 10% to 15% of patients may develop MM over the course of time and treatment will be needed.

Smoldering multiple myeloma (SMM) patients generally do not show renal failure, nor do they have anaemia, hypercalcemia or lytic bone lesions.  But, they do show some M protein production and/or bone marrow plasma cells equal to or more than 10%.  SMM is also referred to as asymptomatic meyloma.  These patients are watched carefully and treatment is usually not commenced until the disease progresses.

And the big gorilla of the Classification is symptomatic multiple myeloma (MM) where a patient show M protein in blood and/or urine, malignant bone marrow cells greater than 30% of the sample and may also have anaemia, renal failure, hypercalcemia, or lytic bone lesions.  This is classic MM and demands immediate treatment.

MM affects the body in several ways.  Perhaps the most obvious is the attack on the bones.  As the diseased cells increase in population they show up as soft spots or holes in the bones.  These are called osteolytic lesions or more commonly bone tumours.  These damaged areas make your bones much more susceptible to breakage from falls, over-exertion, or may even produce bone fractures just by breaking down the bones.  It is very common for a MM patient to quickly lose several centimetres of height.  This may occur over a period of a few weeks, not years.

A couple of other critters come into play.  Osteoclasts are cells that act to break down old and worn out bones so that osteoblasts can build new bone.  This is the mechanism by which bones regenerate.  However, in MM the production of osteoclast is increased, the osteoblasts get outnumbered, the bones do not regenerate and bone destruction is accomplished.  As the bones break down calcium is released into the blood and the dangerous condition known as hypercalcemia can occur.

Your blood cells are formed in your bone marrow.  As myeloma cells take over, they inhibit the production of other cells.  Lower production of white blood cells raises risk of infections.  Concurrently, lower red blood cell counts result in anaemia commonly associated with MM.  Fewer platelets interferes with proper blood clotting in the event of an injury; while the higher M protein and light-chain proteins associated with the MM may cause the blood to thicken.

If the blood gets too thick it can impair circulation in the kidneys.  Also, the hypercalcemia overtaxes the kidneys which can't excrete it all and often causes the patient to go into dehydration.  



.

No comments:

Post a Comment