Digital Mammography Has Persistently Increased High-Grade and Overall DCIS Detection Without Altering Upgrade Rate.

ABSTRACT

OBJECTIVE. The purpose of this article is to evaluate whether digital mammography (DM) is associated with persistent increased detection of ductal carcinoma in situ (DCIS) or has altered the upgrade rate of DCIS to invasive cancer. MATERIALS AND METHODS. An institutional review board-approved retrospective search identified DCIS diagnosed in women with mammographic calcifications between 2001 and 2014. Ipsilateral cancer within 2 years, masses, papillary DCIS, and patients with outside imaging were excluded, yielding 484 cases. Medical records were reviewed for mammographic calcifications, technique, and pathologic diagnosis. Mammograms were interpreted by radiologists certified by the Mammography Quality Standards Act. The institution transitioned from film-screen mammography (FSM) to exclusive DM by 2010. Statistical analyses were performed using chi-square test. RESULTS. Of 484 DCIS cases, 158 (33%) were detected by FSM and 326 (67%) were detected by DM. The detection rate was higher with DM than FSM (1.4 and 0.7 per 1000, respectively; p < .001). The detection rate of high-grade DCIS doubled with DM compared with FSM (0.8 and 0.4 per 1000, respectively; p < .001). The prevalent peak of DM-detected DCIS was 2.7 per 1000 in 2008. Incident DM detection remained double FSM (1.4 vs 0.7 per 1000). Similar proportions of high-grade versus low- to intermediate-grade DCIS were detected with both modalities. There was no significant difference in the upgrade rate of DCIS to invasive cancer between DM (10%; 34/326) and FSM (10%; 15/158) (p = .74). High-grade DCIS led to 71% (35/49) of the upgrades to invasive cancer. CONCLUSION. DM was associated with a significant doubling in DCIS and high-grade DCIS detection, which persisted after prevalent peak. The majority of upgrades to invasive cancer arose from high-grade DCIS. DM was not associated with decreased upgrade to invasive cancer.