Search

Background The natural history of breast cancer among BRCA2 carriers has not been clearly established. In a previous study from Iceland, positive ER status was a negative prognostic factor. We sought to identify factors that predicted survival after invasive breast cancer in an expanded cohort of BRCA2 carriers. Methods We studied 608 women with invasive breast cancer and a pathogenic BRCA2 mutation (variant) from four Nordic countries. Information on prognostic factors and treatment was retrieved from health records and by analysis of archived tissue specimens. Hazard ratios (HR) were estimated for breast cancer-specific survival using Cox regression. Results About 77% of cancers were ER-positive, with the highest proportion (83%) in patients under 40 years. ER-positive breast cancers were more likely to be node-positive (59%) than ER-negative cancers (34%) (P P = 0.03); thereafter, the effect was adverse (HR = 1.91; 95% CI 1.07–3.39, P = 0.03). The adverse effect of positive ER status was limited to women who did not undergo endocrine treatment (HR = 2.36; 95% CI 1.26–4.44, P = 0.01) and patients with intact ovaries (HR = 1.99; 95% CI 1.11–3.59, P = 0.02). Conclusions The adverse effect of a positive ER status in BRCA2 carriers with breast cancer may be contingent on exposure to ovarian hormones.

BACKGROUND: Statins have demonstrated antineoplastic effects in breast cancer cell lines, particularly in oestrogen receptor (ER)-negative cell lines. However, epidemiological studies have not supported a preventive effect of statin use against breast cancer. Therefore, we examined the association between statin use and contralateral breast cancer (CBC) risk among women with breast cancer.METHODS: We identified 52,723 women with non-metastatic breast cancer during 1996-2012 from the Danish Breast Cancer Group database. We defined time-varying post-diagnosis statin use as minimum two prescriptions lagged by 1 year. Cox regression analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CBC associated with statin use.RESULTS: Statin use was associated with a lower CBC risk (HR = 0.88; 95% CI = 0.73-1.05). The inverse association was strongest for long-term use overall (HR = 0.64; 95% CI = 0.43-0.96), although the HR specifically for long-term consistent use and high-intensity use approached unity. Among ER-negative breast cancer patients, statin use was associated with a CBC risk reduction (HR = 0.67; 95% CI = 0.45-1.00).CONCLUSIONS: We found some indication that statins reduce the risk of CBC. Further evaluations are needed to disentangle the equivocal results for long-term use and to establish if ER-negative breast cancer patients may benefit most from statin use.

Background: Prevalence of comorbidity at breast cancer diagnosis increases with age and is likely to influence the likelihood of receiving treatment according to guidelines. The aim of this study was to examine the effect of breast cancer treatment on mortality, taking age at diagnosis and comorbidity into account. Methods: Four nationwide population registries in Denmark: the Danish Civil Registration System, the Danish Breast Cancer Cooperative Group, the Danish National Patient Register, and the Danish Register of Causes of Death provided information on 62 591 women diagnosed with early-stage breast cancer, 1990–2008, of whom data on treatment were available for 39 943. Comorbidity was measured using the Charlson Comorbidity Index. Adjuvant treatment were categorised as none, chemotherapy, endocrine therapy, and unknown. Multivariable Cox modelling assessed the effect of comorbidity on breast cancer-specific mortality and other cause mortality according to treatment, adjusting for age at diagnosis and other clinical prognostic factors. Results: The impact of comorbidity on mortality was most pronounced in patients aged 50–79 years. Patients receiving chemotherapy with mild to moderate comorbidity had HR 0.99 (95% confidence interval (CI); 0.82–1.19) and 1.06 (95% CI; 0.77–1.46) for breast cancer-specific mortality, respectively, compared with patients without comorbidity. Conclusion: Comorbidity at breast cancer diagnosis is an independent adverse prognostic factor for death after breast cancer. We identified a subgroup of patients with mild to moderate comorbidity receiving chemotherapy who had similar breast cancer mortality as patients with no comorbidity.

The purpose of this study was to investigate the effect of breast density on breast cancer (BC) mortality in a mammography screening programme. The cohort included 48 052 women participating in mammography screening in Copenhagen, Denmark, where biennial screening is offered to women aged 50-69 years. We collected information for the years 1991-2001 on screening outcome, incident BCs (screen-, interval-, and later detected), and BC deaths. Breast density was dichotomised into fatty (F) and mixed/dense (M/D) breasts. Screening sensitivity was measured as the odds ratio of interval versus screen-detected cancer for dense versus F breasts. Poisson regression was used to estimate the ratios for BC incidence, case fatality, and mortality between women with M/D and F breasts. For women with M/D breasts, the odds ratio of an interval cancer was 1.62 (95% confidence interval, CI, 1.14-2.30), and the age-adjusted rate ratios were 2.45 (95% CI 2.14-2.81) for BC incidence, 0.60 (95% CI 0.43-0.84) for case fatality, and 1.78 (95% CI 1.17-2.72) for BC mortality. The study shows that BC in women with M/D breasts is more frequent, but on average less severe, than in women with F breasts.