(ChemotherapyAdvisor)–False-positive breast cancer screenings are associated with an increased risk of subsequent breast cancer diagnosis, particularly in women with a family history of breast cancer, and women with false-positives should be encouraged to participate in future screenings, according to a retrospective cohort study published in the journal Cancer Epidemiology.

“Women with a false-positive test have an increased risk of cancer detection in subsequent screening participations, especially those with a false-positive result involving cytology or biopsy,” reported Xavier Castells, MD, PhD, of the Department of Epidemiology and Evaluation at the Mar Teaching Hospital in Barcelona, Spain, and coauthors. “The risk of cancer detection increased substantially if women with cytology or biopsy (false-positive) had a familial history of breast cancer (OR 4.64; 95% CI, 3.23-6.66).”

False-positive breast cancer screenings reduce the probability of a woman seeking a subsequent cancer screening, but benign breast lesions “are a known risk factor for subsequent breast cancer” diagnoses, the authors noted. That means that women with an increased risk of breast cancer might be less likely to participate in subsequent cancer screenings.

Continue Reading

However, false-positives have not been well studied as a potential prognostic factor for subsequent cancer diagnoses, the authors noted. To address this gap in the evidence base, they retrospectively analyzed medical record data for 762,506 women ages 45 to 69 years, with at least two screenings during 1990-2006.

“Overall, the cancer detection rate in subsequent screenings observed was 2.89 cases per 1,000 screening mammograms,” the authors reported. “The cancer detection rate for women with a previous false-positive involving an additional imaging procedure and those involving cytology or biopsy was 4.53 and 7.09 cases per 1,000 screening mammograms, respectively.”

False-positives from fine-needle aspiration cytology or biopsy were associated with a higher rate of subsequent cancer detection than imaging exams (cytology: OR 2.69; 95% CI, 2.28-3.16; biopsy: OR 1.81; 95% CI, 1.70-19.4).

“Understanding the factors behind this association could provide valuable information to increase the effectiveness of breast cancer screening,” the authors noted. “Women with a false-positive result should be encouraged to return for further screening as they have an increased cancer detection risk, and a decreased re-attendance probability.”