The association between BMI and multiple myeloma was strongest among men with a BMI of 30 or more. When compared with leaner men (those with a BMI below 22), obese men, the researchers said, were over twice as likely to develop multiple myeloma. The effect was less pronounced among overweight or obese women, yet those women also had an increased risk.
The study also looked at whether regular exercise is related to risk of multiple myeloma. There was not a clear effect of exercise on risk, although the results among women suggested that those who exercise more might have a lower risk. “We cannot say with certainty that exercise reduces the risk of multiple myeloma, but there is ample evidence that regular exercise offers many other health benefits,” Birmann said.
The study findings do show, however, that the effect of BMI on risk of multiple myeloma is separate from any possible effect of physical activity.
According to Birmann, previous research has identified possible biological links between obesity and multiple myeloma. For example, adipocytes, cells found in fat tissue, produce a cell signal, called interleukin-6 (IL-6), which promotes the immune system’s inflammation response. In obese people, this can cause an overproduction of IL-6, which in turn creates a cellular environment that sustains multiple myeloma. “The IL-6 chemical pathway is one possible way obesity could influence the risk of developing diseases like cancer or cardiovascular disease, but the answer might also lie in other relationships between obesity and cancer,” Birmann said.
Further research, she said, will uncover more about the relationships between obesity and cancers such as multiple myeloma. The researchers believe their findings may lead to examination in greater detail of the BMI/multiple myeloma link, including the role of IL-6 and other chemical signals, energy metabolism, and other risk factors such as weight change or weight cycling.
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This research was funded through grants from the Dana-Farber/Harvard Cancer Center Specialized Program in Research Excellence in Multiple Myeloma, the National Cancer Institute and the National Institutes of Health.
The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes nearly 26,000 basic, translational, and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 70 other countries. AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants. The AACR Annual Meeting attracts more than 17,000 participants who share the latest discoveries and developments in the field. Special Conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment, and patient care. AACR publishes five major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. Its most recent publication, CR, is a magazine for cancer survivors, patient advocates, their families, physicians, and scientists. It provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship, and advocacy. |
