Being obese more than doubles the risk of a type of leukemia - acute myelogenous leukemia (AML) - in older women, according to a new report. The risk is only slightly diminished in women who are overweight.

“The fact that survival rates for AML are extremely poor for older individuals makes identifying people who are at increased risk for this cancer of public health importance,” lead author Dr. Julie A. Ross, from the University of Minnesota Cancer Center in Minneapolis, said in a statement.

The findings are based on analysis of data from more than 40,000 women, between 55 and 69 years of age, who participated in the Iowa Women’s Health Study. The subjects completed a health and lifestyle questionnaire when the study began in 1986 and then were followed until 2001.

During follow-up, 74 women developed AML and 88 developed chronic lymphocytic leukemia, the investigators report in the November issue of Cancer Epidemiology, Biomarkers and Prevention.

Compared with having a normal weight, being obese or overweight increased the risk of AML by 140 percent and 90 percent, respectively.

There was little evidence that weight influenced the risk of chronic lymphocytic leukemia, the team found.

“Given that about 65 percent of adults in the US are overweight or obese, the projection we can make from our study is that about 30 percent of AML in older adult women could be due to being overweight or obese,” Ross added

As for why Obesity appears to be linked to AML, she said it could relate to alterations in hormone levels. Whatever the reason, she noted that reducing excess weight could help prevent AML and other malignancies as well.

SOURCE: Cancer Epidemiology, Biomarkers and Prevention, November 2004.