Patient and tumor characteristics of bilateral breast cancer at screening mammography in the Netherlands, a population-based study

Abstract

Few data are available on bilateral breast cancer in the screening population. The aim of this study was to determine patient and tumor characteristics of women with bilateral breast cancer at screening mammography. We included all 350,637 screening mammography examinations of women participating in a biennial screening program in a southern screening region of the Netherlands between May 1998 and January 2010. For referred women, all breast imaging reports, biopsy results, and surgery reports during one year after referral were collected. We compared patient and tumor characteristics of referred women with a diagnosis of bilateral breast cancer or unilateral breast cancer at workup. Bilateral or unilateral breast cancer had been diagnosed in respectively 40 (2.2%) and 1766 (97.8%) of 1806 referred women. Women with bilateral or unilateral breast cancer did not differ significantly in mean age, mammographic breast density, family history of breast cancer, or use of hormone replacement therapy. Compared with index cancers, contralateral cancers comprised significantly more lobular cancers (P = 0.02). Tumor size, mitotic activity, and estrogen receptor status were comparable for both groups, but contralateral cancers had a significantly lower risk of lymph node metastases (P = 0.03). Compared to unilateral breast cancer, contralateral malignancies in women with bilateral breast cancer comprised significantly more lobular cancers (P = 0.004) and lymph node negative cancers (P = 0.01). Contralateral breast cancers detected at screening comprise more lobular cancers and show less nodal involvement than index cancers or unilateral cancers. No differences are observed with respect to other patient and tumor characteristics.

Frequency and diagnostic outcome of bilateral recall at screening mammography

“…It has been shown that especially invasive lobular cancers may be difficult to detect at screening mammography as these cancers frequently present as focal asymmetries, subtle architectural distortions or no mammographic abnormality at all. 1,2,29 We found no significant differences in the histological types of invasive cancers when comparing unilateral and bilateral index cancers. A recent meta-analysis by Yun et al in 2018 suggests that the addition of new imaging modalities to digital screening mammography, such as DBT, may improve the detection of invasive lobular carcinomas.…”

“…Tumors in synchronous bilateral breast cancer may be considered as two biologically separate tumors, and we have previously reported similar tumor characteristics for bilateral cancers and unilateral cancers. 2,33 We found that the final surgical treatment for breast cancer more frequently consisted of mastectomy rather than breast conserving surgery after bilateral recall compared to after unilateral recall. This observation can be explained by the larger tumor size of the index cancers and the higher bilateral breast cancer rate after bilateral recall.…”

“…[5][6][7][8][9][10][11] The detection of bilateral breast cancer has improved as a result of the ongoing developments in breast imaging over the past years. 1,2,[12][13][14] The increased detection of bilateral breast cancer is mostly attributed to the use of magnetic resonance imaging (MRI) after a diagnosis of primary breast cancer. [12][13][14] Data on bilateral recall at screening mammography are very sparse.…”

Concordance of Hormone Receptor Status and BRCA1/2 Mutation Among Women With Synchronous Bilateral Breast Cancer

“…The concordance between MBBC for ER status was much greater than expected for BRCA1/2 mutation (16). Several studies in predominantly symptomatic patients found that BBCs show more favorable tumor characteristics than unilateral cancers, with a higher proportion of invasive lobular cancer, a lower T stage and a higher proportion of hormone receptor positivity (12,17). BRCA1/2 mutations are associated with a high risk of developing contralateral breast cancer by the age of 70 years (18-21).…”

Trends in the use of bilateral mastectomy in England from 2002 to 2011: retrospective analysis of hospital episode statistics

“…Of women diagnosed with breast cancer in the Swedish Cancer Register, around 1% of women were first diagnosed with bilateral breast cancer and less than half a per cent were diagnosed with contralateral breast cancer within 24 months of a first diagnosis,13 and these rates have remained stable or decreased since the 1980s 14. Two recent population-based studies from Australasia and the Netherlands reported comparable bilateral breast cancer rates of 2.3% and 2.2%, respectively 15 16. Assuming trends in the UK are comparable, it is unlikely that a change in incidence alone could explain the observed increase in BM rates.…”