Aromatase inhibition remodels the clonal architecture of estrogen-receptor-positive breast cancers

Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER− ‘collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genome remodelling in a basal-like breast cancer metastasis and xenograft

Massively parallel DNA sequencing technologies provide an unprecedented ability to screen entire genomes for genetic changes associated with tumour progression. Here we describe the genomic analyses of four DNA samples from an African-American patient with basal-like breast cancer: peripheral blood, the primary tumour, a brain metastasis and a xenograft derived from the primary tumour. The metastasis contained two de novo mutations and a large deletion not present in the primary tumour, and was significantly enriched for 20 shared mutations. The xenograft retained all primary tumour mutations and displayed a mutation enrichment pattern that resembled the metastasis. Two overlapping large deletions, encompassing CTNNA1, were present in all three tumour samples. The differential mutation frequencies and structural variation patterns in metastasis and xenograft compared with the primary tumour indicate that secondary tumours may arise from a minority of cells within the primary tumour

Initial outcomes for patients treated on the American Society of Breast Surgeons MammoSite clinical trial for ductal carcinoma-in-situ of the breast.

BACKGROUND: The MammoSite device was designed as a breast brachytherapy applicator and is currently used to deliver accelerated partial breast irradiation (APBI). We hypothesized that APBI delivered with the MammoSite device would be well tolerated and be associated with a good cosmetic outcome in patients with ductal carcinoma-in-situ (DCIS). METHODS: From 2002 to 2004, 191 patients with DCIS were enrolled in a registry trial to assess the MammoSite applicator. Fifteen patients were excluded from analysis because of device- or patient-related factors; 7 patients were excluded after receiving a radiotherapy boost, thus leaving 169 patients available for study. Follow-up information was available for 158 patients. The average length of follow-up was 7.35 months. Forty-three patients had at least 1 year of follow-up. RESULTS: Skin spacing for the MammoSite applicator was as follows: \u3c 5 mm, 3 patients (1.78%); 5 to 7 mm, 18 patients (10.65%); and \u3e or = 7 mm, 148 patients (87.57%). Patients with a device-to-skin distance of \u3e or = 7 mm had the best cosmetic result. Patients with a device-to-skin distance of \u3e or = 7 mm also had a lower incidence of radiation dermatitis. Data on 43 patients who were followed up for at least 1 year confirmed these findings. Additional adverse events were primarily related to skin changes, with breast infections occurring in five patients (3.16%). No patient in the study has experienced a recurrence. CONCLUSIONS: APBI delivered via MammoSite is well tolerated in patients with DCIS, and the lowest toxicity was obtained in patients with the greatest device-to-skin distance. Long-term follow-up data regarding patient satisfaction, cosmesis, and efficacy are needed and will be determined from a recently opened large randomized study

Effect of the neuroprotective compound SR57746A on nerve growth factor synthesis in cultured astrocytes from neonatal rat cortex

1. The neurotrophic factor promoting activity of the neuroprotective compound SR57746A was evaluated in primary cultures of neonatal rat cortical astrocytes by studying the synthesis of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). 2. A concentration- and time-dependent increase of nerve growth factor mRNA was induced by SR57746A (10 nM–1 μM). In these astrocytes, BDNF mRNA contents were increased to a significant but smaller extent, and β-actin mRNA showed no variation. 3. SR57746A (1 μM) induced increases of both de novo protein translation after 6 h of incubation and NGF release into the extracellular medium after 6–24 h. 4. These effects were preceded by a transient augmentation of junB, c-fos and c-jun mRNA contents. These increases of AP-1 family mRNA were associated with increased nuclear AP-1 binding activity. 5. The results show that SR57746A can increase the synthesis and release of NGF in rat cortical astrocytes. Such effects may contribute to the drug's previously described neuroprotective effects