Why are men more likely to develop multiple myeloma than women? Study identifies several clinical features

Micrograph of a plasmacytoma, the histologic correlate of multiple myeloma. H&E stain. Credit: Wikipedia/CC BY-SA 3.0

Rates of multiple myeloma (MM), the second most common blood cancer in the United States, are increasing and are twice as high in men than in women. A new study published online in Cancer provides insights that may help to explain this disparity.

To investigate the sex difference in MM, researchers analyzed data on 850 patients with newly diagnosed MM enrolled in the Integrative Molecular And Genetic Epidemiology (IMAGE) study at the University of Alabama at Birmingham.

Compared with female patients, male patients were more likely to have advanced (International Staging System stage III) disease at the time of diagnosis. Males were also more likely to have high myeloma load—serum monoclonal protein (an abnormal protein produced by cancerous blood cells), more organ failure (especially kidney failure), and bone damage.

Men were less likely than women to have low bone mineral density, and myeloma-defining features tended to differ between the two sexes. These differences were apparent even after taking numerous factors into account—including race, age, body mass index, education, income, smoking, and alcohol use.

Analyses suggested that certain chromosomal abnormalities that lead to initiation of myeloma occurring more often in younger males may help to explain some of the differences seen in this study.

“This research suggests that sex-specific mechanisms promote multiple myeloma pathogenesis, which may account for the excess risk seen in men,” said lead author Krystle L. Ong, Ph.D., of the O’Neal Comprehensive Cancer Center at the University of Alabama at Birmingham.

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

Multiple myeloma develops differently in men and women, study reveals