Mammographic density and breast cancer risk: the role of the fat surrounding the fibroglandular tissue

Introduction

Both the percent of mammographic density and absolute dense (fibroglandular) area are strong breast cancer risk factors. The role of non-dense (fat) breast tissue is not often investigated, but we hypothesize that this also influences risk. In this study we investigated the independent effects of dense and fat tissue, as well as their combined effect on postmenopausal breast cancer risk.

Methods

We performed a nested case-control study within the EPIC-NL cohort (358 postmenopausal breast cancer cases and 859 postmenopausal controls). We used multivariate logistic regression analyses to estimate breast cancer odds ratios adjusted for body mass index and other breast cancer risk factors.

Results

Large areas of dense (upper (Q5) vs lower quintile (Q1): OR 2.8 95% CI 1.7 to 4.8) and fat tissue (Q5 vs Q1: OR 2.4; 95% CI 1.3 to 4.2) were independently associated with higher breast cancer risk. The combined measure showed that the highest risk was found in women with both a large (above median) area of dense and fat tissue.

Conclusions

Fibroglandular and breast fat tissue have independent effects on breast cancer risk. The results indicate that the non-dense tissue, which represents the local breast fat, increases risk, even independent of body mass index (BMI). When studying dense breast tissue in relation to breast cancer risk, adjustment for non-dense tissue seems to change risk estimates to a larger extent than adjustment for BMI. This indicates that adjustment for non-dense tissue should be considered when studying associations between dense areas and breast cancer risk.

Effect of the application of trial inclusion criteria on the efficacy of adalimumab therapy in a rheumatoid arthritis cohort

OBJECTIVE

To evaluate the influence of inclusion criteria used in rheumatoid arthritis (RA) trials with adalimumab on clinical outcome and response.

METHODS

The different inclusion criteria of published trials of adalimumab in RA were separately applied to a large prospective cohort of patients with RA treated with adalimumab (AdRA cohort), thereby mimicking patient selection for a clinical trial. Clinical response and outcome in the resulting 11 projection groups were compared using the 28-joint Disease Activity Score (DAS28) and time-averaged DAS28 as outcome measures of efficacy.

RESULTS

Thirteen trials (n = 54-799) with 11 different sets of entry criteria were identified, resulting in 11 projection groups (n = 22-168). The DAS28 at baseline was similar in the original trial and each projection group based on this trial (5.1-6.4, total AdRA cohort 5.1). After 28 weeks, the efficacy varied substantially among the 11 projected groups (change from baseline DAS28: -1.65 to -2.65, time-averaged DAS28 3.67-4.53). Expressed as outcome (DAS28 at 28 weeks), the efficacy was much more similar for almost all projection groups (3.5-4.0) and thus appeared to be mostly independent of disease activity at baseline.

CONCLUSION

We observed that different inclusion criteria for clinical trials can have a marked effect on the expected response, i.e., improvement from baseline. A novel finding is that final disease activity appeared much less dependent on initial disease activity. Our study suggests that for daily practice, one can assume that adalimumab treatment will on average result in a DAS28 between 3.5 and 4.0 after 28 weeks of treatment, regardless of baseline disease activity.

Two-year neurodevelopmental outcome of preterm born children ≤ 750 g at birth

OBJECTIVES

To describe 2-year neurodevelopmental outcome (NDO) in a cohort of extremely low birthweight infants, and compare NDO between two consecutive 5-year periods and between appropriate (AGA, ≥p10) and small for gestational age (SGA, <p10) infants.

DESIGN

Retrospective cohort study.

SETTING

Wilhelmina Children's Hospital, Utrecht, the Netherlands.

PATIENTS

146 children, born between 1996 and 2005, with a birth weight ≤750 g and a gestational age ≥24 weeks, admitted to the neonatal intensive care unit. 111 children (76%) survived the neonatal period.

INTERVENTIONS

At 2 years corrected age, 101 children (cohort I: born in 1996-2000, n=45 and cohort II: born in 2001-2005, n=56) were assessed with either the Griffiths Mental Developmental Scales or the Mental Scale of the Bayley Scales of Infant Development, second edition.

MAIN OUTCOME MEASURES

NDO, classified as normal (≤-1 Z score ≥0), mildly delayed (>-1 Z score ≤-2) or severely delayed (Z score >-2).

RESULTS

74.3% of the children had a normal NDO at 2 years corrected age, 20.8% a mildly and 5% a severely delayed outcome. Although survival significantly increased with time (65.8% to 88.1%, p=0.002), significantly fewer children in cohort II (66.1% vs 84.4% in cohort I, p=0.042) as well as fewer SGA children (64.3% vs 86.7% of AGA children, p=0.012) had a normal NDO.

CONCLUSIONS

Increased survival of infants with a birth weight ≤750 g coincided with more children with an impaired NDO at 2 years corrected age. SGA infants are especially at risk of impaired NDO.

Neurodevelopmental outcome over time of preterm born children ≤750 g at birth

BACKGROUND

Extremely low birth weight (ELBW) infants are at risk of cognitive impairment and follow-up is therefore of major importance. The age at which their neurodevelopmental outcome (NDO) can reliably be predicted differs in the literature.

AIMS

To describe NDO at 2, 3.5 and 5.5 years in an ELBW cohort. To examine the value of NDO at 2 years corrected age (CA) for prediction of NDO at 3.5 and 5.5 years.

STUDY DESIGN

A retrospective cross-sectional and longitudinal cohort study.

SUBJECTS

101 children with a BW≤750 g, born between 1996 and 2005, who survived NICU admission and were included in a follow-up program.

OUTCOME MEASURES

NDO, measured with different tests for general development and intelligence, depending on age of assessment and classified as normal (Z-score≥-1), mildly delayed (-2≤Z-score<-1) or severely delayed (Z-score<-2).

RESULTS

At 2, 3.5 and 5.5 years 74.3, 82.2 and 76.2% had a normal NDO. A normal NDO at 2 years CA predicted a normal NDO at 3.5 and 5.5 years in 92% and 84% respectively. Of the children with a mildly or severely delayed NDO at 2 years CA the majority showed an improved NDO at 3.5 (69.2%) and 5.5 years (65.4%) respectively.

CONCLUSIONS

The majority of the children with a BW≤750 g had a normal NDO at all ages. A normal NDO at 2 years CA is a good predictor for normal outcome at 3.5 and 5.5 years, whereas a delayed NDO at 2 years CA is subject to change with the majority of the children showing a better NDO at 3.5 and 5.5 years.

External validation of the UK Prospective Diabetes Study (UKPDS) risk engine in patients with type 2 diabetes

AIMS/HYPOTHESIS

Treatment guidelines recommend the UK Prospective Diabetes Study (UKPDS) risk engine for predicting cardiovascular risk in patients with type 2 diabetes, although validation studies showed moderate performance. The methods used in these validation studies were diverse, however, and sometimes insufficient. Hence, we assessed the discrimination and calibration of the UKPDS risk engine to predict 4, 5, 6 and 8 year cardiovascular risk in patients with type 2 diabetes.

METHODS

The cohort included 1,622 patients with type 2 diabetes. During a mean follow-up of 8 years, patients were followed for incidence of CHD and cardiovascular disease (CVD). Discrimination and calibration were assessed for 4, 5, 6 and 8 year risk. Discrimination was examined using the c-statistic and calibration by visually inspecting calibration plots and calculating the Hosmer-Lemeshow χ(2) statistic.

RESULTS

The UKPDS risk engine showed moderate to poor discrimination for both CHD and CVD (c-statistic of 0.66 for both 5 year CHD and CVD risks), and an overestimation of the risk (224% and 112%). The calibration of the UKPDS risk engine was slightly better for patients with type 2 diabetes who had been diagnosed with diabetes more than 10 years ago compared with patients diagnosed more recently, particularly for 4 and 5 year predicted CVD and CHD risks. Discrimination for these periods was still moderate to poor.

CONCLUSIONS/INTERPRETATION

We observed that the UKPDS risk engine overestimates CHD and CVD risk. The discriminative ability of this model is moderate, irrespective of various subgroup analyses. To enhance the prediction of CVD in patients with type 2 diabetes, this model should be updated.

Prediction models for prolonged intensive care unit stay after cardiac surgery: systematic review and validation study

BACKGROUND

Several models have been developed to predict prolonged stay in the intensive care unit (ICU) after cardiac surgery. However, no extensive quantitative validation of these models has yet been conducted. This study sought to identify and validate existing prediction models for prolonged ICU length of stay after cardiac surgery.

METHODS AND RESULTS

After a systematic review of the literature, the identified models were applied on a large registry database comprising 11 395 cardiac surgical interventions. The probabilities of prolonged ICU length of stay based on the models were compared with the actual outcome to assess the discrimination and calibration performance of the models. Literature review identified 20 models, of which 14 could be included. Of the 6 models for the general cardiac surgery population, the Parsonnet model showed the best discrimination (area under the receiver operating characteristic curve=0.75 [95% confidence interval, 0.73 to 0.76]), followed by the European system for cardiac operative risk evaluation (EuroSCORE) (0.71 [0.70 to 0.72]) and a model by Huijskes and colleagues (0.71 [0.70 to 0.73]). Most of the models showed good calibration.

CONCLUSIONS

In this validation of prediction models for prolonged ICU length of stay, 2 widely implemented models (Parsonnet, EuroSCORE), although originally designed for prediction of mortality, were superior in identifying patients with prolonged ICU length of stay.