PAM50 subtyping and ROR score add long-term prognostic information in premenopausal breast cancer patients.

PAM50 intrinsic subtyping and risk of recurrence (ROR) score are approved for risk profiling in postmenopausal women. We aimed to examine their long-term prognostic value in terms of breast cancer-free interval (BCFi) and overall survival (OS) (n = 437) in premenopausal women randomised to 2 years of tamoxifen versus no systemic treatment irrespective of hormone-receptor status. Intrinsic subtyping added independent prognostic information in patients with oestrogen receptor-positive/human epidermal growth factor 2-negative tumours for BCFi and OS after maximum follow-up (overall P-value 0.02 and 0.006, respectively) and those with high versus low ROR had worse prognosis (maximum follow-up: hazard ratio (HR)BCFi: 1.70, P = 0.04). The prognostic information by ROR was similar regarding OS and in multivariable analysis. These results support that PAM50 subtyping and ROR score provide long-term prognostic information in premenopausal women. Moreover, tamoxifen reduced the incidence of breast cancer events only in patients with Luminal APAM50 tumours (0-10 years: HRBCFi(Luminal A): 0.41, HRBCFi(Luminal B): 1.19, Pinteraction = 0.02).Trial registration: This trial is registered in the ISRCTN database, trial ID: ISRCTN12474687.

Genome-wide interaction analysis of menopausal hormone therapy use and breast cancer risk among 62,370 women.

Use of menopausal hormone therapy (MHT) is associated with increased risk for breast cancer. However, the relevant mechanisms and its interaction with genetic variants are not fully understood. We conducted a genome-wide interaction analysis between MHT use and genetic variants for breast cancer risk in 27,585 cases and 34,785 controls from 26 observational studies. All women were post-menopausal and of European ancestry. Multivariable logistic regression models were used to test for multiplicative interactions between genetic variants and current MHT use. We considered interaction p-values < 5 × 10-8 as genome-wide significant, and p-values < 1 × 10-5 as suggestive. Linkage disequilibrium (LD)-based clumping was performed to identify independent candidate variants. None of the 9.7 million genetic variants tested for interactions with MHT use reached genome-wide significance. Only 213 variants, representing 18 independent loci, had p-values < 1 × 105. The strongest evidence was found for rs4674019 (p-value = 2.27 × 10-7), which showed genome-wide significant interaction (p-value = 3.8 × 10-8) with current MHT use when analysis was restricted to population-based studies only. Limiting the analyses to combined estrogen-progesterone MHT use only or to estrogen receptor (ER) positive cases did not identify any genome-wide significant evidence of interactions. In this large genome-wide SNP-MHT interaction study of breast cancer, we found no strong support for common genetic variants modifying the effect of MHT on breast cancer risk. These results suggest that common genetic variation has limited impact on the observed MHT-breast cancer risk association.

Tumour-infiltrating lymphocytes as a prognostic and tamoxifen predictive marker in premenopausal breast cancer: data from a randomised trial with long-term follow-up.

BACKGROUND: Tumour-infiltrating lymphocytes (TILs) are of important prognostic and predictive value in human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC) and triple-negative breast cancer (TNBC), but their clinical relevance in oestrogen receptor-positive/HER2-negative (ER+/HER2-) remains unknown. The primary study aim was to analyse the prognostic effect of TILs on the BC-free interval (BCFi) in premenopausal patients stratified by BC subtypes. The secondary aim was to investigate if TILs are predictive of tamoxifen (TAM) benefit. METHODS: Archival tissues from primary breast tumours were collected from patients from the SBII:2pre trial, in which 564 premenopausal women were randomised to 2 years of adjuvant TAM or no systemic treatment, regardless of hormone receptor status. TILs were scored on whole tissue sections from 447 patients with available ER status. Tumours were divided into ER+/HER2-, HER2+ and TNBC subtypes by immunohistochemistry and in situ hybridisation. The prognostic value of TILs was analysed in systemically untreated patients (n = 221); the predictive information was investigated in the ER+ subgroup (n = 321) by cumulative incidence curves and Cox regression analyses. The median follow-up was 28 years. RESULTS: High (≥ 50%) infiltration of TILs was a favourable prognostic factor in terms of BCFi (univariable analysis: hazard ratioBCFi (HRBCFi) 0.40; 95% confidence interval (CI) 0.22-0.71; P = 0.002). Similar effects were observed across all BC subtypes. The effect of adjuvant TAM was stronger in patients with ER+ tumours and TILs < 50% (HRBCFi 0.63; 95% CI 0.47-0.84; P = 0.002) than in patients with high immune infiltration (≥ 50%) (HRBCFi 0.84; 95% CI (0.24-2.86); P = 0.77). However, evidence for differential effects of TAM in categories of TILs, i.e. interaction, was weak. CONCLUSIONS: We demonstrate a long-term favourable prognostic value of high infiltration of TILs in a cohort of premenopausal BC patients and the positive prognostic effect was extended to the ER+/HER2- subgroup. A beneficial effect of TAM in ER+ patients was observed in patients with tumours of low TIL infiltration, but evidence for a treatment predictive effect was weak. TRIAL REGISTRATION: This trial is registered in the ISRCTN database, trial ID: ISRCTN12474687 .

Physical activity and survival following breast cancer.

INTRODUCTION: Physical activity (PA) leads to improved survival in women following the diagnosis of breast cancer, but it is less clear whether PA has equally positive effects regardless of age at diagnosis. The purpose of our study was to evaluate the association between post-diagnosis PA and survival in women aged below or over 55 years at diagnosis. METHODS: From a prospective population-based cohort of Swedish women, we included 847 women, aged 34-84 years, who were diagnosed with breast cancer from 1992 to 2012. A PA score was calculated based on three different questions regarding self-reported PA. Cox proportional hazard model was used to estimate the association between PA and mortality. RESULTS: A significant association between PA score and all-cause mortality was observed, in a dose-response manner (ptrend  = 0.01). The mortality was clearly lower in the most active compared to the least active group (hazard ratio 0.29, 95% confidence intervals 0.09-0.90). A subgroup analysis showed that the improved survival was only seen in women over 55 years of age at diagnosis. CONCLUSION: Physical activity, which is a modifiable lifestyle factor, should be encouraged after breast cancer diagnosis, especially in women with post-menopausal breast cancer.

Imidazole and dimethyl aminopropyl-functionalized hyperbranched polymers for nucleic acid transfection.

In order to mimic the histidine binding motives of naturally occurring histones as DNA complexing proteins, hyperbranched poly(ethylene imine) and polyglycerol were functionalized with imidazole or 3-dimethylamino propyl groups. These new polycationic polymers were tested for interaction with dye-labelled oligonucleotide and DNA using UV and fluorescence spectroscopy and gel electrophoresis. Formation of stable complexes was observed above N/P ratios of 4 for unfunctionalized and 8 for functionalized PEIs. No stable complexes were formed with polyglycerol-based polyamines up to N/P 16. Cytotoxicity determined by MTT assay of all functionalized PEI polymers was found to be significantly lower than for unfunctionalized PEI. PG-based polymers showed no toxicity in the tested concentration range. Dynamic light scattering showed that only for PEI(21)-Imidaz polyplexes hydrodynamic diameters below 250 nm could be reached.The influence of functionalization and polymer type on transfection efficiency was evaluated in L929, NIH/3T3 and HeLa cells. Only imidazole-functionalized PEIs reached similar transfection efficiencies as unfunctionalized PEIs, while 3-dimethylamino propyl modification resulted in lower transfection efficiencies. We also demonstrated that the polymer plays an important role for transfection properties since, regardless of the modifications of polyglycerol, only low transfection efficiencies were observed at functionalization levels below 50%.

Dendritic polyamines: simple access to new materials with defined treelike structures for application in nonviral gene delivery.

Polycationic dendrimers are interesting nonviral vectors for in vitro DNA delivery. We describe a simple approach to the synthesis of dendritic polyamines with different molecular weights and adjustable flexibility (degrees of branching; DB). Both parameters influence the transfection efficiency and the cell toxicity of the polymer. Functionalization of hyperbranched polyethylenimine (PEI) by a two-step procedure generated fully branched pseudodendrimers (analogues of polypropylenimine (PPI) and polyamidoamine (PAMAM) dendrimers). The DNA transfection efficiencies observed for these polymers depended on the cell line investigated. The highest efficiencies were observed for polymers whose unfunctionalized PEI cores had molecular weights in the range M(w)=6000-25 000 g mol(-1). The cytotoxicity of the dendrimers generally rises with increasing core size. The data collected for NIH/3T3 and COS-7 cells indicate a maximum transfection efficiency at around 60 % branching for the PPI analogues, and at a PEI-core molecular weight of M(w)=25 000 g mol(-1). PAMAM functionalization of PEI (M(w)=5000 and 21 000 g mol(-1)) leads to polymers with little or no cytotoxity in the cell lines investigated.