Mammography is the primary imaging modality in screening and early detection of breast cancer, yet it still has its fallacies. Its limitations, particularly in women with dense breasts and/or at risk for breast cancer, have led to the invention of improved and tailored techniques to patient risk [10].
Breast MRI is currently considered to be the most sensitive imaging modality in the detection of breast cancer with sensitivity approaching 95–100%, as proved by large trials to screen high-risk women [11]. The American College of Radiology recommends annual screening breast MRI in addition to an annual mammogram in women at high risk of developing breast cancer and, more recently, those with a personal history of breast cancer who have dense breasts or those diagnosed before age 50 years among women with a 15–20% lifetime risk of breast cancer [5].
Contrast-enhanced MRI-combined morphofunctional approach enforces the basis of the vascular-based technique; CEM, which can possibly serve as its alternative [10, 12]. CEM images reliably enhanced diagnostic performance when compared with digital mammography, ultrasound, and DBT, with overall performance comparable with CE-MRI [13].
Since women with BRCA mutations have increased risk of interval cancers, some of them stagger screening mammography and MRI at 6-month intervals instead of performing both examinations on the same day (stacked screening) [14]. Furthermore, in such patients with high risk for breast cancer, CEM can replace conventional FFDM allowing contrast-enhanced screening test to be performed every 6 months [10]. It was observed that in high-risk women screening, CEM is much better tolerated than CE-MRI due to its shorter examination time [15].
In the current study, we assessed the additive role of contrast-enhanced mammography in patients with increased risk of developing breast cancer and its capability in overcoming mammographic deficiencies.
In this prospective study, we included 283 consecutively registered women (with increased risk of developing breast cancer) who underwent screening (127/283 (49.1%)) or diagnostic (156/283 (55.1%)) FFDM and CEM, we have found that 177/283 (62.5%) cases had malignant lesions (Fig. 1), and 106/283 (37.5%) cases had benign lesions (Fig. 2).
In our study population, none of the factors we studied correlated with breast cancer development. This might be attributed to the limited number of cases included in our study.
In contrast to Ozsoy et al., where they concluded that among the risk factors for breast cancer, the presence of breast cancer in family was found to be the most important risk factor. They also stated that there was no relationship identified in terms of the presence and duration of breastfeeding, the use of OCP, and the use of HRT and breast cancer risk [16].
The mean age in our study in patients with malignant lesions was 48.5 ± 11.5, and it is much lower than that reported in other studies [16, 17]. This matches with the reported age incidence in Egypt which is 10 years younger than Europe and USA [18].
In the current study, CEM increased the accuracy of BIRADS assessment of malignant cases (Figs. 3 and 4) and also helped in the detection of patients with multifocal and multicentric lesions.
In view of our results, contrast-enhanced mammography technique has the potential to improve characterization of breast lesions (Fig. 5). It contributed to marked reduction in the number of false-positive and false-negative cases. The sensitivity, specificity, and positive predictive value of CEM were 92.7, 71.4, and 84.6%, respectively, and of mammography were 80.9, 59.0, and 77.0%, respectively.
These results are supported by Dromain et al.’s study, which was performed on 110 patients with 148 breast lesions. They confirmed the superior diagnostic accuracy of CEM in addition to sonomammography with sensitivity of 93% [19].
Luczyńska et al. also concluded that contrast-enhanced mammogram has improved sensitivity and specificity in breast cancer detection through a study performed on 152 consecutive patients with 173 breast lesions diagnosed on conventional mammogram or CEM [20]. ElSaid et al. also agreed with these results [21].
Sung et al. recently stated that CEM has the potential to be an alternative screening technique to two-dimensional full-field in women at increased risk of breast cancer with sensitivity of 87.5% (compared with 50.0% for FFDM) and specificity of 93.7% [10].
In our study, CEM was of special value in patients with dense breast tissue in both screening and non-screening context giving a greater diagnostic confidence and less operator dependency than mammography alone (Figs. 3, 4 and 5). It also acted as a problem-solving technique, decreasing the number of unnecessary biopsies in cases with intermediate lesions (BIRADS 3 or 4 lesions on mammography) such as areas of asymmetry with no underlying ultrasound findings.
Our study had some limitations; the fundamental one was that the cases included in the study were not cases that participated in the general community screening, but were cases that presented to our hospital for opportunistic screening or diagnostic purpose mostly upon clinician’s referral. There may be statistical differences between general community screening cases and cases that presented to the hospital.
The other limitation was the limited number of cases included in the study. Studies with larger series are needed to be able to clearly identify the risk factors related to the community in Egypt.
The last and major limitation was the selection of cases, which was only based on modifiable and non-modifiable risk factors and not BRCA gene mutation.
Contrast-enhanced mammography is a promising technique that deserves all the attention previously and currently given to MRI and that is why further multicenter studies with large number of patients is needed to validate the positive CEM results.
