Diagnostic Accuracy of Opportunistic Breast Cancer Screening Based on Mammography in Iran

Although breast cancer is the most prevalent type of cancer among Iranian women, its screening is opportunistic in Iran. The available guidelines for breast cancer screening are based on mammography. A screening modality should have adequate diagnostic accuracy and be widely available at reasonable cost. Although mammography is highly accessible in Iran, its accuracy has not been investigated.

This study aimed to evaluate the accuracy of mammography in opportunistic screening regarding the current rate of patient attendance.

A total of 491 women undergoing screening mammography were followed-up based on their medical records. They were divided into positive and negative screening groups, based on the breast imaging-reporting and data system (BI-RADS) categories and approaches. To evaluate the disease status of positive cases, pathology reports were investigated, and negative cases were followed-up for stability over time.

In the study sample, sensitivity was estimated at 73.08% (95% CI: 55.21 - 88.93), specificity was estimated at 94.41% (95% CI: 91.91 - 96.32), and accuracy was 93.28% (95% CI: 90.69 - 95.33). These test accuracy indices were not significantly different between the groups regarding age, family history, breast density, and history of breast interventions.

The test’s sensitivity or ability to detect a disease was relatively low in opportunistic screening; it was found to be similar to the results of studies of first time implementation of screeninng. In both settings, a test needs to diagnose both incident and prevalent cases. The overall accuracy of mammography was acceptable, even in opportunistic screening.