Breast cancer survivors who are overweight have a higher risk of developing second primary cancers, according to results from a study conducted by Kaiser Permanente researchers that were published April 5 in the Journal of the National Cancer Institute.
Obesity is associated with an increased risk of several types of cancer, with an estimated 55% of all cancers in women occurring in those who are overweight or obese.
In a study of 6,481 women led by Heather Feigelson, PhD, from the Kaiser Permanente Colorado Institute for Health Research, 822 (12.7%) developed a second cancer. The majority of women were overweight (33.4%) or obese (33.8%) at the time of their initial diagnosis.
The mean age at initial breast cancer diagnosis was 61 years, and most (82.2%) of the cohort was white. Black women comprised a small percentage of the cases but were more likely to be obese. Of the Black women in the cohort, 50.9% were obese, compared with 33.6% of the white women.
The outcomes evaluated included the following: all second cancers, obesity-related second cancers, any second breast cancer, and estrogen receptor-positive second breast cancers. Obesity-related cancer includes colorectal, uterine, ovarian, and pancreatic cancer.
