Current statistical methods that women can use to assess breast cancer risk are woefully inadequate. They consider such factors as age, family history, and whether a woman has ever had any breast biopsies to calculate whether she's at average or increased risk of breast cancer. But the models are only about 55 to 60 percent accurate at predicting who's at increased risk.
Measuring levels of sex hormones via a blood test could help improve predictability of these models, according to research results presented last week by Boston researchers at the American Association for Cancer Research conference. The researchers were able to analyze hormone levels in 473 blood samples obtained from women who participated in the Harvard Nurses Health study two decades earlier, and went on to develop breast cancer. They compared these hormone levels to those of 770 other study participants who did not develop breast cancer. They found that a form of estrogen, testosterone, and another hormone prolactin were all more likely to be elevated early in those who went on to develop breast cancer.
"We confirmed what we and others have previously seen — that these hormones are associated with breast cancer risk," said study coauthor Shelley Tworoger, an epidemiologist at Brigham and Women's Hospital. Adding such a measurement to the current risk models could increase their predictability by 4 to 6 percentage points, she added.