Radiological review of incidence breast cancers

Abstract

Objectives-To examine the rate of incidence cancers detectable on review of previous screening mammograms using two reviewing methods. To compare the results with a previous study of interval cancers using the same reviewing methods. Setting-Almost 50 000 women are regularly invited for service screening at Stockholm Söder Hospital. From 1989 to 1993, 119 women were identified with breast cancer detected at screening and the previous round attendance (incidence cancer). Methods-Screening mammograms, obtained before detection of the incidence cancers, were reviewed first mixed with other screening images (ratio 1:8) and then non-mixed. Reviewers from the screening unit responsible for the mammograms as well as reviewers from other units interpreted all images by both single and double reading. Results-The proportion detected on retrospective review varied between 5% and 50% depending on the review method used and the number of reviewers included to classify a case as truly identified. Generally more cancers were detected when non-mixed samples of mammograms were reviewed than when mixed samples were reviewed (mean increase 23%) and when interpreted by double reading compared with single reading (mean increase 14%). Conclusions-In an experimental retrospective set up, fewer incidence cancers were identified in mixed than in nonmixed review. Generally more incidence cancers were identified on review (22%) than previously reported for interval cancers (14%), probably reflecting diVerences in tumour biology and growth. How many women with potentially visible incidence cancers would have benefited from earlier tumour detection still needs to be evaluated. (J Med Screen 2000;7:177-183) Keywords: breast neoplasm; mammography; incidence cancer; cancer Breast screening with mammography has in randomised trials been shown to reduce mortality from breast cancer.1-4 Maintaining these results in ordinary service screening requires continuous high quality of all the components of the screening procedure, including the radiologist's performance. The rate of breast cancers overlooked or misinterpreted as the result of observer error has sometimes been used as a quality measurement of radiological interpretation. 5Such cancers could be detected either at the next screen (incidence cancer) or in the time interval before the next screen (interval cancer). [6][7][8] Consequently, to be able to estimate the number of women who have breast cancers overlooked/misinterpreted, the mammograms of both interval and incidence breast cancers should be reviewed, preferably in a set up imitating the screening procedure. Most review studies have not included screen detected cancers, and few studies give details of how the review procedure was performed.When reviewing 44 screen detected cancers, not mixed with other screening images, van Dijck et al 9 classified 9% as "screening error" and 48% as showing "minimal signs present" on previous mammograms compared with 18% and 28% respectively of 40 interval cancers. In a study by Harvey et...

Influence of Annual Interpretive Volume on Screening Mammography Performance in the United States

“…In our study, radiologists detected a mean of 4.2 cancers per 1000 mammograms with a sensitivity of 85.2%. Because false-negative cases are rare (one per 1000 mammograms) and some are visible only in retrospect (29)(30)(31)(32), it could take many years for a low-volume reader to miss a fi nding that an expert might identify. This is a smaller problem for high-volume readers.…”

Recurrence quantification analysis of radiologists' scanpaths when interpreting mammograms

“…Breast cancer is the most common nonmelanoma cancer among women, and it is the leading cause of cancer‐related deaths among women worldwide. In the developed countries, in spite of the increase in the breast cancer incidence rates, the mortality rates from this disease have been decreasing over the last few decades due to improvements in treatment options and early detection through screening mammography . However, interpretation of mammograms is a challenging task and prone to false‐positive and false‐negative errors.…”

“…However, interpretation of mammograms is a challenging task and prone to false‐positive and false‐negative errors. In previous studies, false‐negative rates ranged from 12% to 50% depending on the characteristics of the mammograms included in the database . It is estimated that 49% of women screened annually for a 10‐yr period will experience at least one false‐positive mammogram .…”

“…In the developed countries, in spite of the increase in the breast cancer incidence rates, the mortality rates from this disease have been decreasing over the last few decades 1 due to improvements in treatment options 2 and early detection through screening mammography. [3][4][5] However, interpretation of mammograms is a challenging task and prone to false-positive and false-negative errors. In previous studies, false-negative rates ranged from 12% to 50% depending on the characteristics of the mammograms included in the database.…”

“…In previous studies, false-negative rates ranged from 12% to 50% depending on the characteristics of the mammograms included in the database. 4,5 It is estimated that 49% of women screened annually for a 10-yr period will experience at least one false-positive mammogram. 6 Given the high prevalence of false-positive and false-negative errors in the interpretation of mammograms, the medical image perception community has focused on better understanding of how radiologists interpret mammograms and the underlying causes of the errors.…”