Frequency and characteristics of contralateral breast abnormalities following recall at screening mammography

Frequency and diagnostic outcome of bilateral recall at screening mammography

Our study was performed to determine the frequency of recall for bilateral breast lesions at screening mammography and compare its outcome with respect to unilateral recall. We included 329 132 screening mammograms (34 889 initial screens and 294 243 subsequent screens) from a Dutch screening mammography program between January 2013 and January 2018. During a 2‐year follow‐up, we collected radiological data, pathology reports and surgical reports of all recalled women. At bilateral recall, the lesion with the highest Breast Imaging Reporting and Data System score was used as the index lesion when comparing screening mammography characteristics at bilateral vs unilateral recall. A total of 9806 women were recalled at screening (recall rate, 3.0%). Bilateral recall comprised 2.8% (271/9806) of all recalls. Biopsy was more frequently performed after bilateral recall than unilateral recall (54.6% [148/271] vs 44.1% [4201/9535], P < .001), yielding a lower positive predictive value (PPV) of biopsy after bilateral recall (42.6% vs 51.7%, P = .029). The PPV of recall was comparable for both groups (23.2% [63/271] vs 22.8% [2173/9535], P = .85). Invasive cancers after bilateral recall were larger than those diagnosed after unilateral recall (P = .02), but histological subtype, histologic grading, receptor status and proportions of lymph node positive cancers were comparable. Bilateral recall infrequently occurs at screening mammography. Biopsy is more frequently performed following bilateral recall, but the PPV of recall is similar for unilateral and bilateral recall. Invasive cancers of both groups show comparable pathological features except of a larger tumor size after bilateral recall.

What's new?

Data on bilateral breast cancer in a screened population is sparse, and information on bilateral recall is lacking. Based on more than 329,000 screening mammograms, our study shows that bilateral recall occurs infrequently at screening mammography, and that the majority of these recalls are false positives. Invasive cancer has comparable pathological features in bilateral and unilateral breast cancer patients, except larger tumour size after bilateral recall. Altogether, the results highlight the need for screening radiologists to pay vigorous attention to the contralateral breast after detecting a screening mammographic abnormality in order to facilitate a timely diagnosis of bilateral breast cancer.

Frequency and characteristics of additionally detected ipsilateral breast lesions following recall at screening mammography

PURPOSE

To determine the frequency and outcome of additionally detected ipsilateral breast abnormalities following recall at screening mammography.

METHODS AND MATERIALS

We included a consecutive series of 130,338 screening mammograms obtained between January 1, 2014 and January 1, 2016. During 2-year follow-up, clinical data were collected of all recalls. Women with a bilateral recall (115) and women recalled for multiple lesions in one breast (165) were excluded from the analyses. Screening outcome parameters were determined for recalled women with or without evaluation of additional ipsilateral breast abnormalities following recall.

RESULTS

A total of 3995 women were recalled (recall rate, 3.1%). In 258 (6.4%) of these women, another lesion was detected in the ipsilateral breast than the one for which she had been recalled. Biopsy was more frequently performed of additionally detected ipsilateral lesions than of recalled lesions (55.8% (144/258)) versus 39.7% (1375/3457), (p < 0.001)). The proportion of malignancy in recalled lesions and additionally detected lesions was comparable (21.5% (743/3457) versus 19.0% (49/258), p = 0.34). Of all 144 biopsies of additionally detected ipsilateral lesions, 9 revealed a synchronous tumour in addition to a malignant recalled lesion, and 33 biopsies revealed multicentric or multifocal tumours. In 5 women, the recalled lesion turned out to be benign, whereas the additional lesion in a different quadrant was malignant at biopsy. A total of 97 biopsies showed benign findings.

CONCLUSION

A substantial proportion of women are analyzed for additional ipsilateral breast lesions following recall. These lesions are more frequently biopsied than recalled lesions, but have a comparable probability of being malignant. The majority of additionally detected cancerous lesions are part of multifocal or multicentric malignancies.