Breast Cancer Susceptibility Increases With Age and Weight: JAMA Study

A Women's Health Initiative clinical trial has found that overweight or obese postmenopausal women are at an increased risk of aggressive breast cancer.

Published in JAMA Oncology, a randomized clinical trial by the Women's Health Initiative followed 67,142 postmenopausal women with annual or biennial mammography across 40 sites around the country. The women, between 50 and 79 years of age, were followed for a median of 13 years.

The study found that compared with women of normal weight, those who were classified as overweight or obese had a greater risk of developing invasive breast cancer than those who were overweight or obese. Some of the findings of the study include:

  • BMI of ≥35, high risk of estrogen receptor—positive breast cancer
  • Obesity grade 2 and 3 associated with advanced breast cancer, including large tumor size, positive lymph nodes, and death
  • Women who gained >5% body weight during follow-up were at an increased risk of breast cancer

The authors conclude that this study should motivate obesity prevention programs.