Biological subtyping of early breast cancer: a study comparing RT-qPCR with immunohistochemistry

The biological subtype of breast cancer influences the selection of systemic therapy. Distinction between luminal A and B cancers depends on consistent assessment of Ki-67, but substantial intra-observer and inter-observer variability exists when immunohistochemistry (IHC) is used. We compared RT-qPCR with IHC in the assessment of Ki-67 and other standard factors used in breast cancer subtyping. RNA was extracted from archival breast tumour tissue of 769 women randomly assigned to the FinHer trial. Cancer ESR1, PGR, ERBB2 and MKI67 mRNA content was quantitated with an RT-qPCR assay. Local pathologists assessed ER, PgR and Ki-67 expression using IHC. HER2 amplification was identified with chromogenic in situ hybridization (CISH) centrally. The results were correlated with distant disease-free survival (DDFS) and overall survival (OS). qPCR-based and IHC-based assessments of ER and PgR showed good concordance. Both low tumour MKI67 mRNA (RT-qPCR) and Ki-67 protein (IHC) levels were prognostic for favourable DDFS [hazard ratio (HR) 0.42, 95 % CI 0.25–0.71, P = 0.001; and HR 0.56, 0.37–0.84, P = 0.005, respectively] and OS. In multivariable analyses, cancer MKI67 mRNA content had independent influence on DDFS (adjusted HR 0.51, 95 % CI 0.29–0.89, P = 0.019) while Ki-67 protein expression had not any influence (P = 0.266) whereas both assessments influenced independently OS. Luminal B patients treated with docetaxel-FEC had more favourable DDFS and OS than those treated with vinorelbine-FEC when the subtype was defined by RT-qPCR (for DDFS, HR 0.52, 95 % CI 0.29–0.94, P = 0.031), but not when defined using IHC. Breast cancer subtypes approximated with RT-qPCR and IHC show good concordance, but cancer MKI67 mRNA content correlated slightly better with DDFS than Ki-67 expression. The findings based on MKI67 mRNA content suggest that patients with luminal B cancer benefit more from docetaxel-FEC than from vinorelbine-FEC.

Prevalence of atrial fibrillation and association of previous antithrombotic treatment in patients with cerebral microbleeds

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMBs) are associated with an increased risk of intracerebral hemorrhage. The impact of oral anticoagulation (OAC) on CMBs is not well characterized. Our aim was to assess the prevalence of CMBs in stroke and transient ischaemic attack (TIA) patients with atrial fibrillation (AF) and to analyze the implications of previous treatment with OAC.

METHODS

In this retrospective analysis on data from a prospectively recruiting stroke registry, patients with ischaemic stroke or TIA with brain magnetic resonance imaging including susceptibility weighted imaging were consecutively enrolled during a 3-year period. For each patient cardiovascular risk factors, AF history and recent diagnosis of AF, present use of OAC and antiplatelets, the National Institute of Health Stroke Scale and the premorbid modified Rankin Scale score were recorded. Two independent raters identified CMBs according to consensus criteria. CMB location was classified as lobar, deep or in the posterior fossa.

RESULTS

In all, 785 patients (mean age 63.9 ± 14.2 years) were included. At least one CMB was detected in 186 (23.7%) patients. CMBs were significantly more frequent in patients with AF (30.5% vs. 22.4%). Patients with previous OAC treatment were more likely to have CMBs (36.7% vs. 22.8%, P = 0.03) and abundant CMBs (n > 10) were more frequent in anticoagulated patients even after adjustment for age. However, age was the only independent factor predicting CMBs (P = 0.001).

CONCLUSIONS

Cerebral microbleeds are common in elderly AF patients with acute ischaemic stroke. Previous OAC is associated with a higher number of CMBs predominantly in the lobar location. Establishing a causal relationship requires prospective longitudinal investigation.

Prevalence of renal dysfunction in ischaemic stroke and transient ischaemic attack patients with or without atrial fibrillation

BACKGROUND AND PURPOSE

Chronic kidney disease (CKD) is associated with a higher risk of stroke and atrial fibrillation (AF). There are limited data on the comorbidity of renal dysfunction and AF in stroke patients. Our aim was to determine the frequency of kidney dysfunction in ischaemic stroke patients with and without AF.

METHODS

In a prospectively collected, single center cohort of acute ischaemic stroke and transient ischaemic attack (TIA) patients, glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease equation on admission. Renal function was graded into five categories (cat.): cat. 1, eGRF ≥90 ml/min/1.73 m(2); cat. 2, 60-89; cat. 3, 30-59; cat. 4, 15-29; cat. 5, <15. The diagnosis of AF was based on medical history, a 12-lead electrocardiogram (ECG) and 24-h Holter or continuous ECG monitoring.

RESULTS

In total, 2274 patients (1727 stroke, 547 TIA; median age 71.0) were included. Median eGFR was 78.6 ml/min/1.73 m(2) (interquartile range 61/95); 21.1% were in cat. 3, 2.1% in cat. 4, 0.7% in cat. 5. In all, 535 patients (23.5%) suffered from AF; 28.0% of these were in cat. 3, 2.6% and 0.8% in cat. 4 and cat. 5, respectively. In multivariable analysis, age [odds ratio (OR) 1.1], diabetes (OR 1.8), heart failure (OR 1.7) and AF (OR 1.4) were independently associated with kidney dysfunction (eGFR < 60).

CONCLUSIONS

Renal dysfunction is far more common in stroke patients than in the general population and more common in AF-related stroke. These findings may have implications for the choice of anticoagulants.

Genome-wide DNA methylation events in TMPRSS2-ERG fusion-negative prostate cancers implicate an EZH2-dependent mechanism with miR-26a hypermethylation

Prostate cancer is the second most common cancer among men worldwide. Alterations in the DNA methylation pattern can be one of the leading causes for prostate cancer formation. This study is the first high-throughput sequencing study investigating genome-wide DNA methylation patterns in a large cohort of 51 tumor and 53 benign prostate samples using methylated DNA immunoprecipitation sequencing. Comparative analyses identified more than 147,000 cancer-associated epigenetic alterations. In addition, global methylation patterns show significant differences based on the TMPRSS2-ERG rearrangement status. We propose the hypermethylation of miR-26a as an alternative pathway of ERG rearrangement-independent EZH2 activation. The observed increase in differential methylation events in fusion-negative tumors can explain the tumorigenic process in the absence of genomic rearrangements.

SIGNIFICANCE

In contrast to TMPRSS2-ERG -rearranged tumors, the pathomechanism for gene fusion-negative tumors is completely unclear. Using a sequencing-based approach, our work uncovers significant global epigenetic alterations in TMPRSS2-ERG gene fusion-negative tumors and provides a mechanistic explanation for the tumor formation process.

Whole-body MRI and MRA for evaluation of the prevalence of atherosclerosis in a cohort of subjectively healthy individuals

Objectives

To assess the prevalence of cardiovascular findings in asymptomatic individuals by means of 1.5-T whole-body magnetic resonance imaging and angiography.

Methods

A cohort of 138 individuals (118 men, 20 women) with a mean age of 54 years (SD ± 7.55) was referred to whole-body MRI at 1.5-T, including contrast-enhanced whole-body MR angiography (MRA) and cardiac MRI. A total of 2,065/2,070 vessel segments (99.8%) and cardiac function were evaluated.

Results

Approximately one-fourth of the participating individuals had vascular abnormalities. In 17 subjects (12.3% of all subjects) significant luminal narrowing was observed in at least one vascular segment. Luminal narrowing (mild to severe) was observed in 1 (0.7% of all subjects respectively) of the renal arteries, 7 (5.0%) of the carotid arteries, and 3 (2.2%) of the pelvic and upper leg arteries, and in 17 segments (12.3%) of arteries in the lower leg.

In cardiac function and perfusion imaging, wall motion disorders were observed in six patients (4.3%), with additional delayed enhancement and isolated delayed enhancement present in two cases. Functional parameters differed from reference values in 55 cases.

Conclusions

Even in an asymptomatic cohort of middle-aged predominantly male individuals, atherosclerotic disease is not uncommon and is detectable by whole-body MRI.

Main Messages

In middle-aged predominantly male individuals, atherosclerotic disease is not uncommon.

Even in an asymptomatic collective, approximately one fourth had vascular abnormalities.

Using whole-body MR angiography (MRA), 99.8% of 2,070 vessel segments could be evaluated.