MM is uncommon cancer. It accounts for 1% of all cancers. Its estimated worldwide 5-year prevalence is 230,000 people. According to the National Cancer Institute, in 2018, an estimated 149,956 people were living with multiple myeloma in the United States.
Read on to find out about the genetic and hereditary links of MM. This article will also discuss its signs, risk factors, stages, and outlook.
Somatic genetic mutations in plasma cells cause MM. This means that the mutations are acquired during a person’s lifetime and not inherited. While an increased risk of developing the condition seems to run in families, its inheritance pattern is not known.
While some reports show that MM runs in families, it does not in all cases. According to the American Cancer Society, most people with MM have no affected family member. This shows that family history only accounts for a small number of MM cases.
Also, according to a publication by the International Myeloma Foundation, only about 5–7% of myeloma cases occur in people who have close relatives previously diagnosed with the medical condition.
Like other types of cancer, MM has a genetic component. Scientists are still researching exactly the role genes play in MM and the genes involved.
Different studies have shown that genetics play a role in the condition, causing its onset and worsening over time. The genetic factors can be traced back to an individual’s chromosomes (23 pairs in total) that carry the genetic information.
A 2018 article indicated that people with a mutation in the gene lysine-specific demethylase 1 (LSD1/KDM1A) had a 6–9 times higher risk of developing MM.
MM can also be linked to chromosomal damage — for example, chromosomal translocation.
Chromosomal translocation occurs when one chromosome breaks off and fuses to another chromosome. A 2018 study of cytogenetic approaches in the characterization of MM observed that 50–70% of MM cases have chromosomal translocations, with over 90% of the translocations involving chromosome 14 in the IGH locus.
Other genes that may contribute to the risk of developing MM include:
- DIS3: About 10% of MM cases show that DIS3 is mutated.
- FAM46C: This is one of the most commonly mutated genes in MM.
- TP53: TP53 deletion or mutation is often present in B-cell malignancies such as MM.
- NRAS: NRAS is one of the genes frequently implicated in MM.
- KRAS: This gene’s mutation is present in about 36% of MM cases.
Factors that can increase a person’s risk of developing MM include:
- Age: The risk of developing most cancers, including MM, increases as a person advances in age.
- Obesity: Being overweight or having obesity can increase the risk of having MM.
- Racial background: Research suggests that MM symptoms begin earlier in Black people. MM is also twice more likely to occur in Black people compared to white people.
- Having other plasma diseases: People with plasma diseases such as solitary plasmacytoma and monoclonal gammopathy of undetermined significance have a higher risk of developing MM.
- Family history: MM may run in families. This means that a person who has a family member with MM will be more likely to develop the condition than someone else that does not have a family history of MM. However, this only accounts for a few cases of MM.
The signs and symptoms of MM can be hard to detect. Some people have no symptoms at all, and some do not show symptoms at the onset of the disease.
However, for people who do show symptoms, some common symptoms to look out for include:
- bone pain, especially around the spine and chest region
- frequent infections
- nausea
- constipation
- numbness or weakness in the legs
- confusion
- excessive thirst
- loss of appetite
- broken bones (fractures) and bone weakness
- low blood counts
- dehydration
- sudden, severe back pain
- shortness of breath
- leg swelling
Note that some of these symptoms can signify other diseases. If you experience two or more of these symptoms simultaneously, it is advisable to see a doctor for a proper diagnosis.
Learn about how doctors diagnose MM here.
MM has three stages. The International Myeloma Working Group published the Revised International Staging System (R-ISS) for multiple myeloma in 2015. The staging is based on four factors:
- the amount of lactate dehydrogenase (LDH) in the blood
- the amount of beta-2-microglobulin in the blood
- the amount of albumin in the blood
- the specific gene abnormalities (cytogenetics) of cancer
Below is a table that shows the R-ISS.
| R-ISS stage group | Factors or criteria |
|---|---|
| Stage 1 | serum beta-2-microglobulin less than 3.5 (mg/l); and normal LDH levels; and albumin level that is 3.5 (g/dl) or more; and cytogenetics that are not considered risky |
| Stage 2 | not stage 1 or stage 3 |
| Stage 3 | serum beta-2-microglobulin greater than 5.5 (mg/l); and cytogenetics considered “high-risk”; and/or high LDH levels |
Your doctor can explain this staging system further to you.
The outlook for people with MM at present looks more promising than a decade ago. This is because scientists and clinicians now understand the condition better. Scientists have discovered that MM is an array of diverse conditions with genetic differences affecting how each progresses.
Also, new treatments now exist that can help improve the condition.
More than 50% of people with myeloma will survive for 5 years or more after diagnosis.
Survival will depend on many factors, such as age, fitness, and the stage of the myeloma when it was diagnosed.
If your myeloma responds to treatment, it will go into remission. This means there will be no physical signs of your sickness. This can last for months or years.
However, MM may recur and need further treatment at that point. Some people may have a better outlook than others. It is always best to talk to your doctor about your symptoms and personal outlook.
Learn more about the outlook for MM here.
MM is a rare type of cancer that affects plasma cells. Even though it is not completely hereditary, it has a genetic link that increases a person’s chances of having it if they have a family history of the condition. Other risk factors for the condition include age, obesity, other disease conditions, and race.
There are available treatment options for MM, and people can recover from it, especially if they commence treatment early. It is best to talk with a healthcare professional if you have questions, are confused about anything related to the condition, or believe you are at risk of developing the disease.
