Obesity found to be a risk factor for multiple myeloma

An obese person is more likely than a lean person to develop multiple myeloma, according to researchers from Brigham and Women’s Hospital, Harvard Medical School, and Harvard School of Public Health.

Their findings indicate that Body Mass Index (BMI) – a statistical measure that scales weight to height – provides an indicator for one’s risk of developing multiple myeloma, a cancer of the blood cells that produce antibodies. Multiple myeloma currently affects more than 50,000 people in the U.S., and the five-year survival rates of the cancer are below 40 percent.

The study, published in the July issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, takes its data from over 100,000 participants in the on-going Nurses’ Health Study and Health Professionals Follow-up Study, two similar large-scale studies. The study findings were similar to those from previously published studies that included smaller numbers of multiple myeloma patients, and/or were based on a one-time recording of height and weight.

“I find the results of these studies encouraging, since they show consistent results about the first risk factor for multiple myeloma that people can actually modify,” said the study’s lead author Brenda M. Birmann, Sc.D., a researcher in the Department of Medicine at Brigham and Women’s Hospital and Harvard Medical School. “Treatment options for this disease are improving, but it is also important to identify risk factors that could be modified. We would like to learn how to prevent its occurrence.”

The Brigham and Women’s Hospital-based Nurses’ Health Study has followed the health of female registered nurses since 1976, and the Health Professionals Follow-up Study, based at Harvard School of Public Health, has followed males from several health professions since 1986. These studies recorded height, weight and physical activity for each person enrolled, as well as diet, medications, smoking habits and other health behaviors, and has updated that information every two to four years. Of the 136,623 participants who qualified for their study protocol, Birmann and her colleagues confirmed 215 cases of multiple myeloma.

Body Mass Index (BMI) is computed by dividing a person’s weight by the square of their height. A BMI between 18.5 and 25 is considered optimal, a BMI of 25-29 is considered overweight, and a BMI of 30 or higher is considered obese.

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.

Source: American Association for Cancer Research

Related stories:

Mayo researchers explore issues related to multiple myeloma treatment
Multiple myeloma (MM) is a cancer of plasma cells that affects approximately 3 in 100,000 people each year. Although there is no cure for this disease, researchers have developed treatments that help relieve pain, control complications, and slow the progress of MM in many patients. Unfortunately, some of the most effective therapies also have toxic side effects that can pose serious health risks and reduce quality of life. In the October issue of Mayo Clinic Proceedings, two articles authored by Mayo researchers address the issue of how to balance the risks and benefits associated with MM treatments.
Being Overweight May Raise Cancer Risk
Researchers from the University of Manchester, Christie Hospital and University of Bern in Switzerland have today published findings in the Lancet medical journal which further support the link between obesity and risk of developing cancer.
Oral osteoporosis meds appear to reduce the risk of jaw degradation
BOSTON, Mass. (Jan. 2, 2008) — Athanasios Zavras began receiving messages from distraught patients in 2005 after case reports linked oral osteoporosis meds to bone death in the jaw. A number of doctors and dentists advised women and men taking these drugs to postpone dental work, fearing that procedures such as tooth extractions would exacerbate the problem. That’s when Zavras, an associate professor in the Harvard School of Dental Medicine, decided to take a closer look at the purported link.
Overweight and obesity cause 6,000 cancers a year in UK women
Following last week's report by the World Cancer Research Fund, evidence of the relevance of obesity to the risk of a wide range of cancers in UK women is published online by the BMJ today.
Gene profiling can single out the worst cases of multiple myeloma and guide therapy
Multiple myeloma patients vary widely in how they respond to treatment, but now researchers at the Myeloma Institute for Research and Therapy at the University of Arkansas for Medical Sciences have identified a small subset of genes whose activity could predict high-risk cases and potentially guide therapy in the future.
Firefighters higher risk for some cancers
Firefighters are more likely to develop certain types of cancer than workers in other fields, University of Cincinnati researchers said.
On the trail of a targeted therapy for blood cancers
Investigators from the Herman B Wells Center for Pediatric Research at the Indiana University School of Medicine are focusing on a family of blood proteins that they hope holds a key to decreasing the toxic effects of chemotherapy in children and adults.
Indo-Australian study identifies genetic region involved in schizophrenia risk
A study involving an Indian population has led to an important discovery in schizophrenia genetics.

News discussion:

Medicine & Health news