Effect of mammography screening frequency on false-positive biopsy rates and detection of local recurrence among breast cancer survivors.

Abstract

7016 Background: Current guidelines recommend that women with a history of early-stage breast cancer treated with breast-conserving therapy (BCT) continue screening mammography after treatment. One strategy is semi-annual ipsilateral mammography for the first 3 years after diagnosis, when risk of local recurrence is highest. However, a potential harm of more frequent screening is false-positive breast biopsy. We examined the association between screening frequency and rates of false-positive biopsy and local recurrence among breast cancer survivors. Methods: We conducted a retrospective cohort study at Columbia University Irving Medical Center (CUIMC) in New York, NY, of women diagnosed with stage 0-III breast cancer from 2007 to 2017, who were treated with BCT and had at least 2 screening mammograms at CUIMC within the first 3 years after diagnosis. Demographic and clinical information were collected from the electronic health record. Frequency of mammography screening was defined as the median interval between two consecutive mammograms (every 6 months vs. yearly). False-positive biopsy and local recurrence were identified by review of breast pathology reports. A false-positive biopsy was defined as a breast biopsy without evidence of invasive or non-invasive cancer. Descriptive statistics and logistic regression models were conducted to examine relationships between covariates and either false-positive biopsy or local recurrence. Results: In our study cohort (n = 1404), the median age at breast cancer diagnosis was 61 years (range, 24-94), including 45% white, 14% black, 32% Hispanic, and 8% Asian. Eighty percent of women had screening mammography of the ipsilateral breast every 6 months during the first 3 years after diagnosis. Comparing women who screened every 6 months vs. yearly, there was no difference in local recurrence rates (4.0% vs. 4.1%), including screen-detected and invasive recurrences, but a higher rate of false-positive biopsy (13.5% vs. 7.5%). In multivariable analysis, women who screened every 6 months had about a 2-fold increased risk of having a false-positive biopsy (OR 1.93; 95% CI 1.17-3.19); no other factors were significantly associated with false-positive biopsy. Conclusions: We observed that women with early-stage breast cancer treated with BCT who underwent more frequent screening mammography had more false-positive breast biopsies, but no difference in local recurrence rates. Future studies are needed to determine optimal screening strategies for breast cancer survivors.