Multiple myeloma is a treatable but incurable blood cancer that typically occurs in the bone marrow. It is a relatively uncommon cancer, affecting approximately 30,000 new people each year. 1 Difficult to diagnose until it is in the advanced stages, it is mainly treated with chemotherapy and stem cell therapies. But the survival rate is increasing, especially as advances in treatment are being discovered. Here are the ten things you need to know about the disease.
Please note: nothing can replace the care of your clinician or doctor. Please do not make changes to your treatment or schedules without first consulting your healthcare providers. This article is not intended to diagnose or treat illness.
1. What is multiple myeloma?
Multiple myeloma is a type of cancer that typically occurs within a bone due to the presence of malignant plasma cells. Under normal circumstances, plasma cells develop from B cells—a type of cell that the immune system uses to fight disease or infection. When B cells react to an infection or disease, they change into plasma cells, which are responsible for creating antibodies to help fight germs. These plasma cells are found mainly in bone marrow.
Sometimes, after plasma cells develop, they can begin to grow out of control and create a tumour called a plasmacytoma. These tumours generally develop within a bone but can occasionally be found in other body tissues. When a person develops more than one of these tumours, they have multiple myeloma.
2. Risk factors and causes
Unlike many other cancers, there are very few known risk factors associated with getting multiple myeloma. These factors are listed below.
- Age: The majority of diagnoses are in people who are more than 45 years old (96 percent), and more than 63 percent of diagnoses are in people older than 65. Less than one percent of cases are in people younger than 35.2
- Race: For reasons unknown, it is more than twice as common in African-Americans than in white Americans.
- Gender: Men are at a slightly higher risk than women.
- Family history: A person with a parent or sibling who has the disease is four times more likely to get the disease, too.
- Obesity: Being overweight or obese increases the risk.
- Having other plasma cell diseases: A person with solitary plasmacytoma (a single tumour), or someone diagnosed with monoclonal gammopathy of undetermined significance, which is a plasma cell disorder that does not normally cause problems, is more likely to later develop multiple myeloma.
- Radiation: People exposed to are at a higher risk.
- Workers exposed to ionizing radiation have been shown to have an increased risk of the disease as well, according to a study conducted at US Department of Energy facilities.
- Workplace exposure: Some studies have shown that workers in occupations such as agriculture, leather, petroleum and cosmetology, and workers exposed to chemicals such as asbestos, benzene, and pesticides are at an increased risk.
Researchers do not have a clear understanding of what causes multiple myeloma, though they have made progress into better understanding how specific DNA changes can cause plasma cells to mutate. Studies show that abnormalities in genes called oncogenes, which promote cell division, develop early in the growth of plasma cell tumours. Studies also show that myeloma cells have abnormalities in their chromosomes; specifically, research has revealed that pieces of chromosome 13 are missing.
Research also shows that in approximately half of people diagnosed with multiple myeloma, a translocation has occurred. This is when “a part of one chromosome has switched with a part of another chromosome in the myeloma cell.” 4 Scientists have also discovered that people with plasma cell tumours have abnormalities in other bone marrow cells, which might cause too much plasma cell growth.