Does digital mammography suppose an advance in early diagnosis? Trends in performance indicators 6 years after digitalization

Abstract

PurposeTo provide a complete evaluation of the long-term impact of full-field digital mammography (FFDM) on the improvement of early diagnosis in a population-based screening program.MethodsWe included 82,961 screen-film mammograms (SFM) and 79,031 FFDM from women aged 50–69 screened biennially from 1995–2010 in Spain and followed-up to 2012. The first screening round of the program was excluded. Rates of cancer detection, interval cancer, tumoral characteristics and other quality indicators were compared between SFM and FFDM periods using the Chi-square test. Multivariate logistic regression models were fitted.ResultsDetection of ductal carcinoma in situ (DCIS) significantly increased with FFDM (0.05 % vs 0.09 %; p = 0.010), along with the proportion of small invasive cancers (<20 mm) (69.37 % vs 78.90 %; p = 0.040). The false-positive rate decreased with FFDM (4.79 % vs 3.38 %; p < 0.001) without differences in the cancer detection rate (0.42 % vs 0.43 %; p = 0.685) or in the interval cancer rate (0.14 % vs 0.14 %; p = 0.816). Adjusted models showed a significant increase in the detection of DCIS in the FFDM periods.ConclusionDigitalization has supposed an improvement in early diagnosis because DCIS and small invasive cancers increased without a change in detection rate. Moreover, false-positive reduction without an increase in the interval cancer rate was confirmed.Key Points• Cancer detection did not increase after 6 years of digital mammography• Ductal carcinoma in situ rates remained higher throughout the digital period• The proportion of small invasive cancers was higher with digital mammography• We observed an improvement in early diagnosis with digital mammography• False-positive rates remained lower throughout the digital period without interval cancer increase

Digital Compared with Screen-Film Mammography: Measures of Diagnostic Accuracy among Women Screened in the Ontario Breast Screening Program

“…This may be partially explained by the borderline significantly higher recall rates and lower positive predictive value with similar cancer detection for DR compared with SFM found in our earlier study (10). While the lower specificity for DR in our study is consistent with the Oslo II randomized controlled trial which evaluates concurrent cohorts of women screened with digital and SFM (13), there was one study that found a significant reduction in false-positive rates for women aged 50-59 years (which would indicate a higher specificity) after the implementation of digital mammography (17,18). Another study, involving women screened with digital mammography in more recent time periods (through 2011) found lower false positive rates for digital mammography BREAST IMAGING: Diagnostic Accuracy of Digital versus Screen-Film Mammography for Screening Prummel et al compared with SFM among initial screens and no difference across technologies for rescreens among women aged 50-69 years (16).…”

“…The OBSP has operated since 1990 to deliver a population-based screening program and offers eligible women aged 50 to 74 years biennial screening with mammography consisting of craniocaudal and mediolateral controlled trial that found similar interval cancer rates, higher sensitivity and significantly lower specificity for digital compared with SFM (13); and one large concurrent cohort study that found interval cancer rates were similar for both modalities (14). Additionally, there have been several studies of women screened with digital mammography compared with a historical SFM cohort which found similar interval cancer rates and sensitivity (15)(16)(17)(18)(19), and a recent systematic review that found the area under curve for summary receiver operating characteristics was similar for digital mammography and SFM in women aged greater than 50 years old (20).…”

Is the false-positive rate in mammography in North America too high?

“…20 From these data, it can be seen that the average FP rate associated with screening mammography in North America can be estimated to fall between approximately 6% and 10%. The North American rates contrast greatly with those observed in Europe, whereby the average FP rate among the first and subsequent screens in the Netherlands and the UK are only 2% 23 and 4.9%, 24 respectively. In accordance with European regulations, these jurisdictions are in compliance with the mandate for limiting the mammography FP rate to below 5%.…”

“…60,[64][65][66][67][68] Among 200,000 females screened over a 6-year period, DCIS was accurately found in 0.09% of the females screened by digital means compared with 0.05% by SFM (p 5 0.010). 23 The most common radiographic appearance of DCIS is microcalcification. 60,66,69 A study demonstrating CAD's ability to identify 100% of cases presenting with microcalcifications provides a plausible explanation for the superior detection of benign and in situ lesions in the digital setting.…”

“…19 In this respect, DCIS should not contribute to the FP incidence, effectively resulting in a slight drop in the FP rate by 0.09%. 23 …”