(HealthDay News) – Women with false-positive mammogram tests remain at significantly higher risk of breast cancer for six or more years, compared to women with negative tests, but the size of the excess risk has decreased since the early 2000s, according to a study published online April 5 in the Journal of the National Cancer Institute.
To determine the long-term risk of breast cancer in women with false-positive tests, My von Euler-Chelpin, PhD, of the University of Copenhagen in Denmark, and colleagues examined data from 58,003 women (aged 50 to 69 years) included in a long-standing population-based screening mammography program.
The researchers found that women with negative tests had an absolute cancer rate of 339 per 100,000 person-years at risk, compared with an absolute rate of 583/100,000 person-years at risk for women with a false-positive test, representing an adjusted relative risk of 1.67 after a false-positive test. Six or more years after the false-positive test, the relative risk remained statistically significantly increased, with point estimates varying between 1.58 and 2.30. The false-positive group from the mid-1990s had a significantly higher risk of breast cancer (relative risk, 1.65) compared with the group with negative tests. However, the relative risk was not significantly different for the false-positive and negative groups from the early 2000s.
“The implementation of new assessment technology coincided with a decrease in the size of excess risk of breast cancer for women with false-positive screening results,” the authors write. “However, it may be beneficial to actively encourage women with false-positive tests to continue to attend regular screening.”
One author is currently employed by Novo Nordisk A/S.