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

Area of Science:

• Radiology and Medical Imaging
• Oncology
• Breast Cancer Screening

Background:

• Digital mammography (DM) has become the standard for breast cancer screening.
• The impact of DM on the detection and progression of ductal carcinoma in situ (DCIS) requires evaluation.
• Understanding changes in DCIS detection and upgrade rates is crucial for optimizing screening protocols.

Purpose of the Study:

• To assess if digital mammography (DM) is linked to a sustained increase in ductal carcinoma in situ (DCIS) detection.
• To determine if DM has influenced the rate at which DCIS is upgraded to invasive cancer.
• To compare DCIS detection and upgrade rates between DM and film-screen mammography (FSM).

Main Methods:

• Retrospective analysis of 484 DCIS cases diagnosed between 2001 and 2014.
• Exclusion criteria included ipsilateral cancer within 2 years, masses, papillary DCIS, and outside imaging.
• Mammograms were interpreted by certified radiologists; the institution transitioned from FSM to DM by 2010. Statistical analysis used the chi-square test.

Main Results:

• DM detected 67% of DCIS cases, compared to 33% by FSM, with a significantly higher detection rate for DM (1.4 vs 0.7 per 1000).
• The detection rate of high-grade DCIS doubled with DM (0.8 vs 0.4 per 1000).
• No significant difference was observed in the upgrade rate of DCIS to invasive cancer between DM (10%) and FSM (10%). High-grade DCIS accounted for 71% of upgrades.

Conclusions:

• Digital mammography (DM) is associated with a significant doubling in the detection of DCIS and high-grade DCIS.
• This increased detection rate persisted after the initial peak and was not linked to a decrease in the upgrade rate to invasive cancer.
• High-grade DCIS remains the primary driver for upgrades to invasive cancer, regardless of the mammography modality used.