Bone marrow, the soft tissue inside your bones, has many important functions, including producing the blood cells that help power your immune system. In fact, nearly half (about 45%) of your blood consists of red blood cells, white blood cells, and platelets. 

Think of your white blood cells as soldiers who fight for your health, if needed. During an infection, the body uses a particular type of white blood cell known as a plasma cell, which creates antibodies to fight it. When these plasma cells start growing in an uncontrolled way in the bone marrow, it may lead to multiple myeloma, or myeloma, which is cancer of the plasma cells. Instead of producing functional antibodies, these myeloma cells will generate abnormal proteins, or immunoglobulins, which can lead to complications in the body.  

Myeloma is a rare type of blood cancer, with approximately 34,000 new cases diagnosed in the United States each year. In total, myeloma accounts for about 1 to 2% of all cancers diagnosed, and about 10% of all blood cancers. Myeloma is more common in men than in women, tends to arise in older adults (the average age of diagnosis is 65-70) and is nearly twice as common in African Americans than it is in the Caucasian population.  

“Myeloma is generally considered an acquired, not a hereditary condition,” says Natalia Neparidze, MD, a Yale Medicine hematologist. “Luckily, over the course of the last two decades, several new, very effective treatments have been developed for myeloma. Thanks to these new treatments, survival in multiple myeloma has greatly improved, often allowing people diagnosed with myeloma to live for many years.”

In a healthy person, plasma cells make up less than 5% of your bone marrow. Plasma cells produce antibodies to fight many of the different types of infection your body may encounter. Abnormal plasma cells, or myeloma cells, can accumulate in the bone marrow and crowd out healthy cells, leading to low blood counts, thinning of bones, and risk of fractures. Myeloma cells produce an abnormal antibody, or immunoglobulin, which is often referred to as an M protein, and can lead to other complications including kidney damage.

Multiple myeloma, a cancer of the blood, is so-named because it is generally widespread, affecting multiple locations in the body. Often the bones are affected, but occasionally soft tissues are involved as well. There is a condition, called plasmacytoma, which refers to myeloma cells affecting only one part of the body, and treatment of a plasmacytoma will often be localized to that one area. 

Though not everything is known about the reasons and the risk factors for developing myeloma, there are certain patterns. The disease affects men more than women, is more common after middle age, and more often found in Black Americans. Several risk factors have been suggested, including exposure to radiation and certain chemicals, chronic inflammation, metabolic syndromes, other environmental causes, and possible genetic risk factors. It is now believed that every case of myeloma develops gradually, from a precursor silent condition called MGUS (monoclonal gammopathy of undetermined significance).

The most common symptoms of myeloma are bone pain and bone fractures. Other symptoms include fatigue and/or weakness (caused by anemia), bruising or bleeding easily, frequent infections and fevers, and kidney damage. In some cases, calcium and M protein build-up caused by myeloma can lead to increased thirst and urination, constipation, headaches, and shortness of breath.

A variety of tests are used to diagnose myeloma, including blood and urine tests to detect the presence of an M protein and other irregularities in the blood. Bone marrow biopsy and imaging tests including X-ray, MRI, PET, and CT scans, can be used to confirm the presence and extent of myeloma, including involvement of the bone and/or soft tissues. In some cases, myeloma is diagnosed incidentally, based on routine blood tests showing low blood counts, or electrolyte or protein abnormalities in the bloodstream.

The treatment of multiple myeloma is usually given in phases, and choice of treatment depends on your overall health and age at diagnosis. Myeloma treatments include the following:

• Chemotherapy, which introduces anticancer drugs to the body to kill cancer cells.
• Targeted therapies, using drugs that will target and kill rapidly reproducing myeloma cells without harming normal ones.
• Blood stem cell transplantation, in which healthy stem cells—generally a person’s own stem cells—are introduced into the bone marrow to replace killed cancer cells after a high dose of chemotherapy.
• Immunotherapies, which are drugs that activate the body’s own immune system to attack cancer cells.
• Radiation therapy, using high-energy rays to kill cancer cells and stop new cancer cells from being produced. Radiation therapy is commonly used in myeloma to relieve bone pain or for people who have plasmacytoma. 
• Surgery is not typically recommended for multiple myeloma, but may be helpful in combination with radiation therapy for treating plasmacytoma.

Yale Medicine offers a strong team of myeloma specialists, who dedicate their time in clinic and in research to studying myeloma. The myeloma team at Yale Medicine takes a multidisciplinary approach in treating patients.

“Treatment decisions are made at myeloma multidisciplinary tumor board conferences, where several myeloma physicians and other specialists, including radiologists, kidney specialists, cardiologists, hematopathologists and radiation oncologists arrive at consensus treatment recommendations,” Dr. Neparidze says. 

The myeloma team at the Smilow Multiple Myeloma and Gammopathies Program offers numerous clinical trial options that provide opportunities for patients to have access to new treatments. Additionally, physicians collaborate closely with research scientists within the Yale Cancer Center and worldwide to study blood and bone marrow in myeloma, and to develop more targeted, personalized treatment strategies for the patients with this diagnosis.