Researchers believe they may have uncovered the reason why multiple myeloma, the second most prevalent blood cancer in the United States, disproportionately affects men.

Multiple myeloma is a bone marrow cancer characterized by the uncontrolled division of white blood cells. This condition can lead to severe bone pain, excessive bleeding, and overwhelming fatigue.

Annually, multiple myeloma accounts for approximately 36,110 new cases across the nation, representing about 1 to 2 percent of all cancer cases. Notably, 55 percent of these patients, translating to around 20,000 individuals, are male.

The disease claims about 12,000 lives each year, yet about 62 percent of those diagnosed survive for at least five years post-diagnosis.

In a recent study, scientists at the University of Alabama examined data from 850 newly diagnosed multiple myeloma patients, with men making up just over half of the group.

Adjusting for variables such as smoking habits, body weight, and age, the study revealed that men are twice as likely as women to be diagnosed with stage 3 myeloma, the most advanced stage where the cancer has metastasized to other parts of the body.

Male multiple myeloma patients were also found to be 71 percent more likely to have impaired kidney function and 24 percent more likely to have organ damage compared to women.

Scientists said the results highlighted that sex-specific differences in biology were driving the disease, rather than differences in lifestyle, such as men being more likely to smoke.

Scientists say they have found out why multiple myeloma is slightly more likely to affect males (stock image)

Researchers said that differences in symptoms suggested sex-specific biological differences in how the disease develops (stock image)

They said the results would help to ensure men diagnosed or suspected to have the cancer would receive more tailored treatment.

Dr Krystle Ong, a pathologist at the University of Alabama who led the study, said: ‘This research suggests that sex-specific mechanisms promote multiple myeloma pathogenesis, which may account for the excess risk seen in men.

‘These findings may be used to improve risk stratification, diagnosis, and tailored treatment for both men and women with newly diagnosed multiple myeloma or related early precursor conditions.’ 

In the study, published in the journal Cancer, 54 percent of the patients were male and 40 percent identified as black. 

They had an average age of 62, with participants ranging from 27 to 91 years old, and an average Body Mass Index (BMI) of 29.1, meaning they were considered overweight. 

Results were adjusted for race, age, body mass index, education, income, smoking and alcohol use.

Men had higher rates of smoking and alcohol use, had a higher annual household income, and were more likely to have hyperlipidemia, too many fats in the blood, than women.

Overall, they were also 72 percent more likely to have high serum monoclonal protein, an excess of identical, abnormal antibodies produced by cancerous cells in the blood, which is common in people with multiple myeloma.

Tom Brokaw, pictured center in May 2017, was diagnosed with multiple myeloma in 2013

Men were also 60 percent more likely to have Kappa light chain disease, a rare plasma cell disorder where abnormal, antibody fragments are overproduced and deposited in organs, also commonly seen in multiple myeloma patients.

On the other hand, men were 41 percent less likely to have osteopenia, weak bones, and 37 percent less likely to have light chain only disease, a build up of antibody fragments in organs, that is also often seen in patients with the disease.

Among those to be diagnosed with multiple myeloma is former NBC Nightly News anchor Tom Brokaw, who was told he had the cancer in 2013 in his early 70s.

Writing in his memoir, A Lucky Life Interrupted: A Memoir of Hope, Brokaw said that the moment he was diagnosed felt like his luck had run out.

He was diagnosed with the disease after his doctor ordered tests because he was suffering from persistent, unexplained back pain. He was treated with chemotherapy and went into remission in 2014.

Today, Brokaw, now 85 years old, continues to take drugs to control the cancer, according to patient support network MyMyelomaTeam.

Multiple myeloma is considered to be treatable but not curable, meaning doctors can control the cancer but are not able to eliminate every cancerous cell from the body. 

Multiple Myeloma is normally treated using chemotherapy or immunotherapy drugs to harness the immune system to attack cancerous cells. Patients may also receive a bone marrow transplant.