Decoding human fetal liver haematopoiesis.

Definitive haematopoiesis in the fetal liver supports self-renewal and differentiation of haematopoietic stem cells and multipotent progenitors (HSC/MPPs) but remains poorly defined in humans. Here, using single-cell transcriptome profiling of approximately 140,000 liver and 74,000 skin, kidney and yolk sac cells, we identify the repertoire of human blood and immune cells during development. We infer differentiation trajectories from HSC/MPPs and evaluate the influence of the tissue microenvironment on blood and immune cell development. We reveal physiological erythropoiesis in fetal skin and the presence of mast cells, natural killer and innate lymphoid cell precursors in the yolk sac. We demonstrate a shift in the haemopoietic composition of fetal liver during gestation away from being predominantly erythroid, accompanied by a parallel change in differentiation potential of HSC/MPPs, which we functionally validate. Our integrated map of fetal liver haematopoiesis provides a blueprint for the study of paediatric blood and immune disorders, and a reference for harnessing the therapeutic potential of HSC/MPPs.

An observational study investigating failure of primary endocrine therapy for operable breast cancer in the elderly.

BACKGROUND: Elderly patients are more likely to have oestrogen receptor positive cancers that can be treated without surgery with primary endocrine therapy (PET). Few studies have sought to identify predictors of failure of PET and so the aim of this study was to evaluate treatment failures in elderly breast cancer patients treated with PET and to determine predictors of failure. METHODS: A retrospective observational study was performed on consecutive patients with ER-positive early stage breast cancer treated with PET between 2005 and 2015 in the three breast units in the North East of England. The primary outcome measure was treatment failure and secondary outcome measure was disease progression. RESULTS: 488 patients were included with mean follow-up 31 months (SD 23). Overall, 206 patients were still alive with their disease controlled at the end of follow-up, 219 had died with their disease controlled and 63 (12%) experienced treatment failure. Younger age [SHR 0.96 (95% CI 0.94-0.99) p 0.013], larger tumours [SHR 1.03 (1.01-1.06) p 0.015], grade 3 cancers [SHR 3.58 (1.93-6.63) p < 0.001] and axillary lymph node metastases [SHR 1.93 (1.06-3.52) p 0.030] were all independent predictors of treatment failure. Disease progression was reported in 86 (17.6%) of patients. CONCLUSIONS: This is the largest retrospective series evaluating PET treatment failure. Clear predictors of failure have been identified, which can be used to facilitate treatment decision making. These results support previous analyses, further validating our results.

Patients electing to have PET rather than surgery for operable breast cancer are a high risk of treatment failure.

BACKGROUND: Primary endocrine therapy (PET) is a treatment option for elderly patients with ER-positive breast cancer enabling frail patients to avoid surgery. As a long-term treatment option, it has been shown to be inferior to surgery in controlling local disease. Decision-making in these patients is crucial in avoiding treatment failure. We examined the influence of decision-making on outcomes of PET failure as a secondary analysis as part of a large observational study. METHODS: Consecutive patients treated with PET between 2005 and 2015 for operable breast cancers were included in a retrospective observational study in 3 breast centres in the North-East. Treatment decision processes were examined by case note review and outcomes of treatment success or failure recorded. RESULTS: 488 patients were included with mean follow-up of 31 months. Overall 63 (12%) experienced treatment failure. 227 (46.6%) were given a choice between surgery and PET at diagnosis. Logistic regression identified older age [OR 0.94 (0.91-0.96) p < 0.001] and reduced mobility [OR 0.6 (0.37-0.97) p 0.036] to be less likely offered surgery. Those offered surgery were more likely to experience treatment failure with PET [SHR 1.78 (1.05-3.02) p 0.033]. CONCLUSIONS: Despite a low failure rate in our series (literature failure rates vary between 12 and 85%), these results suggest that those actively offered a choice between surgery and PET are at greater risk of failure when choosing PET.

Limitations of animal epilepsy research models: Can epileptic human tissue provide translational benefit?

Advancement of understanding the etiology and treatment of epilepsy has largely depended on the use of acute and chronic animal models. An alternative approach, which is being increasingly used by a select number of laboratories worldwide, is to perform functional mechanistic studies in brain slices of living human tissue resected during surgery for drug resistant epilepsies. Pharmacoresistant epilepsy is a major clinical problem with a significant proportion of patients not receiving any symptomatic benefit from available anti-epileptic drugs. Animal models of epilepsy have dominated the landscape with regard to research and development, however they have failed to deliver new agents that would provide seizure control in patients with drug refractory epilepsy. Moreover, these models have considerable issues with respect to validity and animal welfare considerations. A compelling alternative is the use of live human epileptic tissue, which recapitulates a number of key features of refractory epilepsy. The use of live epileptic human tissue offers unprece­dented opportunities to understand the mechanisms associated with difficult to treat epilepsy whilst also permitting studies of efficacy of novel agents that are being developed to alleviate epilepsy in drug resistant patients.

An overview of the genetics, mechanisms and management of NAFLD and ALD.

Alcoholic liver disease (ALD) and, increasingly, non-alcoholic fatty liver disease (NAFLD) are common causes of advanced liver disease in many developed countries including the UK. Both diseases share parallel natural histories, progressing from steatosis, to steatohepatitis and fibrosis/cirrhosis; and are characterised by substantial interindividual variation in disease outcome. This article will provide an overview of disease mechanisms, genetic modifiers and management, focusing principally on NAFLD, while drawing parallels between the two conditions where appropriate.

Clinical relevance of KRAS-mutated subclones detected with picodroplet digital PCR in advanced colorectal cancer treated with anti-EGFR therapy.

PURPOSE: KRAS mutations are predictive of nonresponse to anti-EGFR therapies in metastatic colorectal cancer (mCRC). However, only 50% of nonmutated patients benefit from them. KRAS-mutated subclonal populations nondetectable by conventional methods have been suggested as the cause of early progression. Molecular analysis technology with high sensitivity and precision is required to test this hypothesis. EXPERIMENTAL DESIGN: From two cohorts of patients with mCRC, 136 KRAS, NRAS, and BRAF wild-type tumors with sufficient tumor material to perform highly sensitive picodroplet digital PCR (dPCR) and 41 KRAS-mutated tumors were selected. All these patients were treated by anti-EGFR therapy. dPCR was used for KRAS or BRAF mutation screening and compared with qPCR. Progression-free survival (PFS) and overall survival (OS) were analyzed according to the KRAS-mutated allele fraction. RESULTS: In addition to the confirmation of the 41 patients with KRAS-mutated tumors, dPCR also identified KRAS mutations in 22 samples considered as KRAS wild-type by qPCR. The fraction of KRAS-mutated allele quantified by dPCR was inversely correlated with anti-EGFR therapy response rate (P < 0.001). In a Cox model, the fraction of KRAS-mutated allele was associated with worse PFS and OS. Patients with less than 1% of mutant KRAS allele have similar PFS and OS than those with wild-type KRAS tumors. CONCLUSIONS: This study suggests that patients with mCRC with KRAS-mutated subclones (at least those with a KRAS-mutated subclones fraction lower or equal to 1%) had a benefit from anti-EGFR therapies.