Multiple myeloma is a cancer that affects plasma cells in the bone marrow. Plasma cells are a type of white blood cell that produce antibodies in response to an infection.

In multiple myeloma, these cells grow and divide out of control, leading to tumors in the bones. These tumors can crowd out healthy blood cells, leading to the symptoms associated with multiple myeloma like bone pain and bruising easily.

The National Cancer Institute estimates that multiple myeloma makes up about 1.8 percent of all new cancer diagnoses each year. There are several risk factors for multiple myeloma, including age, genetics, and environmental exposures.

Below, we’ll take a closer look at the different risk factors for multiple myeloma as well as how the condition is diagnosed and treated. Keep reading to learn more.

Before we jump in, it’s important to know that having risk factors for multiple myeloma doesn’t mean that you’ll develop it in the future.

It’s possible to have one or more risk factors and never get multiple myeloma. By the same token, an individual can have no risk factors and still develop multiple myeloma.

The risk of multiple myeloma increases with age. At the time of diagnosis most people with multiple myeloma are aged 65 or older.

The median age at diagnosis is between 66 and 70 years of age. Only about 37 percent of people are under age 65 at the time of diagnosis.

It’s possible for multiple myeloma to occur in young individuals, but this is rare. According to the American Cancer Society (ACS), less than 1 percent of multiple myeloma diagnoses are in people under age 35.

The risk of many types of cancers increases with age. This is believed to be due to the accumulation of cancer-promoting genetic changes over an individual’s lifetime.

Multiple myeloma happens at a slightly higher rate in males than in females. It’s estimated it occurs at a ratio of 3 males to every 2 females. The exact reason for this disparity isn’t known.

Research from 2011 found differences in specific genetic events between males and females with multiple myeloma. The researchers theorized that these differences could influence further genetic changes that contribute to multiple myeloma.

Having other plasma cell conditions can raise a person’s risk of getting multiple myeloma. Let’s look at these now.

Monoclonal gammopathy of undetermined significance (MGUS)

MGUS is a benign condition in which an individual has abnormal plasma cells in the bone marrow. These cells produce an abnormal protein called M protein, which can be detected in the blood and urine.

MGUS often has no signs or symptoms and levels of M protein typically remain stable in many people. Because of this, it’s possible for a person to be unaware that they have MGUS.

However, in some people with MGUS, the condition can progress into multiple myeloma. This occurs at a rate of about 1 percent per year. It’s believed that almost all instances of multiple myeloma are due to MGUS progression.

MGUS can also cause other health issues like amyloidosis or problems with the kidneys or heart.

Solitary plasmacytoma

In solitary plasmacytoma, abnormal plasma cells are found to be concentrated in a single tumor called a plasmacytoma. This condition is rare, making up only about 2 to 5 percent of all plasma cell disorders.

In some cases, a plasmacytoma may be cured. However, solitary plasmacytoma can often develop into multiple myeloma. About 65 to 84 percent of solitary plasmacytomas progress to multiple myeloma in 10 years.

Family history has been found to be associated with increased multiple myeloma risk. A large cohort study in Sweden found that, compared to a control group, close relatives of people with multiple myeloma had about twice the risk of developing the condition themselves.

So, if a close family member, such as a parent or sibling, has been diagnosed with multiple myeloma, you may be more likely to develop it as well.

This is because some genetic changes that increase risk may be passed down from parent to child. A total of 23 genetic regions, which are also associated with MGUS, have been identified as related to multiple myeloma risk.

However, it’s important to note that you can have no family history of multiple myeloma and still develop it.

According to the ACS, multiple myeloma is over twice as common in African Americans compared to white Americans. The exact reason for this difference is unknown and is likely due to a complex combination of factors.

  • One reason for this disparity may have to do with MGUS, which is a precursor condition to multiple myeloma. Several large population studies have found that the prevalence of MGUS is higher in Black people than in white people.
  • MGUS may also progress to multiple myeloma more often in Black people. A 2017 study found that being Black was a risk factor for progression of MGUS to multiple myeloma.
  • It’s also possible that genetics may play a role. A 2016 study found that the effect of family history on myeloma risk was greater in Black people than in white people.
  • Health inequity and racism could also play a role in lower survival rates in Black people.

Having obesity is a risk factor for several different types of cancer, including multiple myeloma. In fact, a 2017 review found strong evidence that an increased body mass index (BMI) raised multiple myeloma risk.

While its exact effects are unknown, having obesity is believed to boost cancer risk in a variety of different ways, including:

  • increasing levels of inflammation in the body
  • altering levels of certain hormones, which may contribute to the growth of cancer cells
  • promoting both cell and blood vessel growth

A 2018 cohort study found that having a high BMI in both early and later adulthood increased multiple myeloma risk. Cumulative change in BMI and average physical activity were not associated with an increased risk.

The same group published a 2019 cohort study assessing weight pattens, body shape, and body fat distribution. They found that:

  • Compared to those who maintained a lean weight pattern, multiple myeloma risk was higher in people with a medium and increasing weight pattern.
  • Multiple myeloma risk went up with increasing hip circumference.
  • Other body fat distribution patterns were not associated with multiple myeloma risk.

Having obesity can also affect progression of MGUS to multiple myeloma. Two 2017 studies documented that having obesity was associated with transformation of MGUS to multiple myeloma.

Certain types of environmental exposures are believed to increase multiple myeloma risk. Some examples include:

  • radiation
  • insecticides or herbicides
  • organic solvents

It’s possible that frequent exposures to these things can cause damage to DNA. This can in turn lead to mutations that may cause or promote the development of cancers, including multiple myeloma.

In addition, some types of occupations have been associated with an increased risk of multiple myeloma, likely due to exposure to some of the agents listed above. Examples include:

  • chemical work
  • construction work
  • farm work
  • metal work
  • painting
  • hairdressing

It’s possible to have multiple myeloma and have very few symptoms or even no symptoms at all. When present, symptoms can include:

Because multiple myeloma can damage the bones, it can also lead to high levels of calcium in the blood (hypercalcemia), which can cause symptoms like:

Diagnosing multiple myeloma

In addition to taking your medical history and performing a physical examination, your doctor can use the following tests to help diagnose multiple myeloma:

  • Laboratory tests. These tests involve the collection of a blood or urine sample. They can be tested in a lab to look for potential indicators of multiple myeloma like low blood count or M protein in the blood or urine.
  • Bone marrow biopsy. A bone marrow biopsy collects a sample of bone marrow. This sample is then analyzed in a lab to look for the presence of abnormal cells.
  • Imaging. Imaging technology can help your doctor get a better idea of what’s going on inside your body. Some examples of imaging that may be used to diagnose multiple myeloma include X-rays, CT scan, and MRI scan.

If multiple myeloma is diagnosed, additional tests will be performed to determine the stage of the cancer. This can also help to inform what type of treatment may be used.

There are a variety of potential treatment options for multiple myeloma.

Which type of treatment is used can depend on several factors, including your age, your overall health, and the stage of the cancer. It’s likely that a combination of therapies will be used.

  • Chemotherapy. Chemotherapy uses strong drugs to kill cancer cells or stop their growth.
  • Radiation therapy. Radiation therapy directs high-energy radiation at cancer cells to kill them or to prevent them from growing.
  • Targeted therapy. Targeted therapy is a type of cancer treatment that uses drugs to target specific molecules on the surface of cancer cells. These drugs can either kill the cancer cells or prevent them from growing.
  • Immunotherapy. Immunotherapy uses your immune system to help target and destroy cancer cells. An example of immunotherapy for multiple myeloma is CAR T-cell therapy.
  • Corticosteroids. Corticosteroids are medications that can have anti-tumor activity for multiple myeloma.
  • Stem cell transplant. In this treatment, a high dose of chemotherapy is used to kill cells in the bone marrow, including cancer cells. Stem cells from either yourself or a donor are transplanted to replace blood-forming cells.
  • Surgery. In cases where a tumor is isolated, it may be able to be removed from the body using surgery. Radiation therapy may be used after surgery to help kill any remaining cancer cells.

The overall outlook for multiple myeloma can vary by individual. It typically depends on several different factors like your age, overall health, and the extent of the cancer.

Your doctor will work alongside you to develop a treatment plan that’s appropriate for your specific situation. Additionally, researchers continue to develop newer, more effective ways to treat cancer, including multiple myeloma.

Generally speaking, the outlook for many types of cancer is improved when it’s detected and treated early. Because of this, be sure to see your doctor if you have any signs or symptoms of multiple myeloma.

Multiple myeloma is a cancer that affects bone marrow cells called plasma cells. When these cells grow and divide out of control, they crowd out healthy blood cells and damage bone tissue, leading to the symptoms of multiple myeloma.

There are several potential risk factors of multiple myeloma. An important one is having another plasma cell condition, particularly MGUS. It’s believed that almost all multiple myelomas are due to progression of pre-existing MGUS.

There are other risk factors for multiple myeloma as well. Some examples include age, genetics, and environmental exposures.

When considering risk factors, keep in mind that having a risk factor for multiple myeloma means that your risk of developing the condition is increased compared to the general population. It doesn’t mean you’ll develop it in the future.