Increasing Weight Linked to Advanced-Stage Breast Cancer
Different rates across weight groups only partly explained by mammography use or accuracy
WEDNESDAY, Nov. 26 (HealthDay News) -- In postmenopausal women who are not on hormone therapy, those who are overweight or obese have higher rates of breast cancer and advanced-stage disease, but these higher rates are not primarily the result of differences in mammography use, according to an article published online Nov. 25 in the Journal of the National Cancer Institute.
Karla Kerlikowske, M.D., of the San Francisco Veterans Affairs Medical Center, and colleagues analyzed 1996-2005 data on 287,115 women who underwent 614,562 mammography examinations. A total 4,446 women were diagnosed with breast cancer within 12 months of a mammography examination.
The researchers found that overweight (body mass index [BMI] 25-29.9), obese (BMI 30-34.9) and very obese women (BMI 35 and above) had significantly higher adjusted rates of breast cancer per 1,000 mammography examinations (7.4, 7.9 and 8.5, respectively) than normal-weight women (6.6). They also found that overweight and obese women had higher rates of advanced breast cancer including large invasive, advanced-stage, and high nuclear grade tumors, regardless of the extent of mammography use.
"Differential cancer detection on mammography examinations across a range of BMI did not contribute to the higher rate of advanced disease observed among women with higher BMI because the rate of non-screen-detected breast cancer (i.e., false-negative cancer) was similar among overweight and obese women compared with normal-weight and underweight women," the authors write.