The role of residential history in cancer research: A scoping review

The role of residential history in cancer prevention, diagnosis, treatment, and survivorship is garnering increasing attention in cancer research. To our knowledge, there is no comprehensive synthesis of the current state of knowledge in the field. We reviewed the extant literature on this topic and conducted a scoping analysis to examine two main research questions: (a) To what degree, and how, have researchers accounted for residential history/mobility in cancer research? and (b) What are the gaps in the literature based on a knowledge synthesis using scoping review and concept mapping? To answer these questions, this scoping analysis focuses on how researchers compile, analyze and discuss residential history/mobility in studies on cancer. The study is focused on peer-reviewed articles from 6 different datasets (PubMed, Cinahl, Scopus, Web of Science and JSTOR, ERIC) from 1990 to August 2020. The review captured 1951 results in total, which was scoped to 281 relevant peer-reviewed journal articles. First, we examined these articles based on cancer continuum, cancer type and the main theme. Second, we identified 21 main themes and an additional 16 sub-themes in the pool of the selected articles. We utilized concept mapping to provide a conceptual framework and to highlight the underlying socioecological assumptions and paradigms. Results show that cancer research incorporating residential histories is primarily focused on incidence and estimating cumulative exposure, with little consideration across the cancer continuum. Additionally, our review suggests that although the social environment plays an important role across the cancer continuum, a small number of articles were focused on such factors and this area remains relatively unexplored. Additionally, the expansion of interdisciplinary research on residential mobility before and after cancer diagnosis will enhance understanding of the role of environmental and socioeconomic characteristics and exposures on cancer continuum.

Abstract PD4-07: Are aromatase inhibitors associated with higher myocardial infarction risk in breast cancer patients? A Medicare population study

Purpose: Aromatase Inhibitors (AIs) are the current standard of care for post-menopausal adjuvant endocrine breast cancer therapy either following or in place of tamoxifen. While their short-term side effect profile was favorable in most studies, findings were mixed regarding cardiotoxicity, and cardiac outcome definitions were not consistent across studies. Given the five or more year duration of adjuvant endocrine therapy, risk of cardiotoxicity in older patients with pre-existing comorbidities remains a particular concern. We examined Myocardial Infarction (MI) as the cardiac outcome in subjects who received AIs vs. tamoxifen in a cohort of Medicare-based breast cancer survivors.

Patients and Methods: We identified women age ≥ 67 years diagnosed with breast cancer from 6/30/2006 to 6/01/2008 in the Surveillance, Epidemiology, and End Results-Medicare (SEER) database , with the following eligibility criteria: stage I-III breast cancer, continuous enrollment in Medicare Parts A and B for 24 months prior to the diagnosis and Part D enrollment for one month after the breast cancer diagnosis to the end of follow up (12/31/2012), adjuvant endocrine therapy (tamoxifen or AI fill) within 12 months after diagnosis. The main study outcome was the time to first diagnosis of MI after initiation of AIs or tamoxifen. MI was defined precisely by ICD9 and ICD10 codes relating both to incidence and death from MI. We developed and assigned stabilized inverse proportion weights to balance the groups, and performed a Fine and Gray hazards model for the outcomes of MI and death for the treatment groups of AIs vs tamoxifen.

Results: Of the cohort of 5,648 women, 4,690 were treated with AIs and 958 with tamoxifen; a total of 251 patients developed and/or died of MI during the study period while 476 died of other causes. The Fine and Gray Model results in a hazard ratio (HR) were not significantly different from one for weighted AI vs Tamoxifen groups [HR=1.01, C.I. 0.72-1.42]. Covariates which significantly affected the risk of MI were previous diabetes, prior other heart disease, prior congestive heart failure, prior MI, and prior peripheral vascular disease. Other covariates included in the weighted model, were age, American Joint Committee on Cancer (AJCC) cancer stage, chemo, Estrogen and progesterone receptor status, low income subsidy, marital status, prior hypertension, prior stroke, per capita income, race, radiation, SEER region, and urbanization.

Conclusions: The occurrence of MI is very low in this cohort (4.4%), reassuring the clinicians that the older adults with comorbidities may not be at a higher risk of MI with adjuvant endocrine therapy. However, the confidence interval for the hazard ratio of AIs vs Tamoxifen is very wide, indicating that a larger sample may be needed for the power of the study to be conclusive.

Citation Format: Kamaraju S, Smith E, Shi Y, Laud P, Neuner J. Are aromatase inhibitors associated with higher myocardial infarction risk in breast cancer patients? A Medicare population study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD4-07.

Extracts from two ubiquitous Mediterranean plants ameliorate cellular and animal models of neurodegenerative proteinopathies

A signature feature of age-related neurodegenerative proteinopathies is the misfolding and aggregation of proteins, typically amyloid-β (Aβ) in Alzheimer's disease (AD) and α-synuclein (α-syn) in Parkinson's disease (PD), into soluble oligomeric structures that are highly neurotoxic. Cellular and animal models that faithfully replicate the hallmark features of these disorders are being increasing exploited to identify disease-modifying compounds. Natural compounds have been identified as a useful source of bioactive molecules with promising neuroprotective capabilities. In the present report, we investigated whether extracts derived from two ubiquitous Mediterranean plants namely, the prickly pear Opuntia ficus-indica (EOFI) and the brown alga Padina pavonica (EPP) alleviate neurodegenerative phenotypes in yeast (Saccharomyces cerevisiae) and fly (Drosophila melanogaster) models of AD and PD. Pre-treatment with EPP or EOFI in the culture medium significantly improved the viability of yeast expressing the Arctic Aβ42 (E22G) mutant. Supplementing food with EOFI or EPP dramatically ameliorated lifespan and behavioural signs of flies with brain-specific expression of wild-type Aβ42 (model of late-onset AD) or the Arctic Aβ42 variant (model of early-onset AD). Additionally, we show that either extract prolonged the survival of a PD fly model based on transgenic expression of the human α-syn A53T mutant. Taken together, our findings suggest that the plant-derived extracts interfere with shared mechanisms of neurodegeneration in AD and PD. This notion is strengthened by evidence demonstrating that EOFI and to a greater extent EPP, while strongly inhibiting the fibrillogenesis of both Aβ42 and α-syn, accumulate remodelled oligomeric aggregates that are less effective at disrupting lipid membrane integrity. Our work therefore opens new avenues for developing therapeutic applications of these natural plant extracts in the treatment of amyloidogenic neurodegenerative disorders.

Pathological α-synuclein impairs adult-born granule cell development and functional integration in the olfactory bulb

Although the role of noxious α-synuclein (α-SYN) in the degeneration of midbrain dopaminergic neurons and associated motor deficits of Parkinson’s disease is recognized, its impact on non-motor brain circuits and related symptoms remains elusive. Through combining in vivo two-photon imaging with time-coded labelling of neurons in the olfactory bulb of A30P α-SYN transgenic mice, we show impaired growth and branching of dendrites of adult-born granule cells (GCs), with reduced gain and plasticity of dendritic spines. The spine impairments are especially pronounced during the critical phase of integration of new neurons into existing circuits. Functionally, retarded dendritic expansion translates into reduced electrical capacitance with enhanced intrinsic excitability and responsiveness of GCs to depolarizing inputs, while the spine loss correlates with decreased frequency of AMPA-mediated miniature EPSCs. Changes described here are expected to interfere with the functional integration and survival of new GCs into bulbar networks, contributing towards olfactory deficits and related behavioural impairments.

Aggregation-prone forms of α-synuclein lead to degeneration of midbrain dopaminergic neurons, as seen in Parkinson’s disease, but less is known about the effects that the noxious protein has in other brain regions. Here, the authors investigate the effect of a pathological form of α-synuclein on the functional integration of new neurons into the olfactory bulb of adult mice.

Medical preparedness, incidents, and group dynamics during the analog MARS2013 mission

Participants on spaceflights and international scientific analog Mars missions can encounter medical incidents (accidents, illnesses) and psychological issues (e.g., stress, group interaction, sleep disturbance, emotions). The aim of this study was to examine these parameters in a field crew living in a desert environment similar to Mars (Group 1) and in Mission Support Center (MSC) personnel on "Earth" (Group 2) during a 4-week mission. Of the 107 medical interventions in the field, 73 mainly minor incidents together with four near accidents and 29 medical checkup interventions were recorded. Of the 32 medical interventions, medical treatments for 23 incidents of minor severity were necessary in Group 2. Injuries (Group 1: 1.4/100 h, Group 2: 0.1/100 h) were significantly increased in the field, and illnesses (Group 1: 0.3/100 h, Group 2: 3.0/100 h) in the MSC personnel. Causes of accidents and illnesses are described. Psychological results show that emotions and stress remained stable in both groups. Sympathy, social competence, teamwork, and leadership showed high scores. These scores were lower on "Earth" but significantly increased in the last weeks. The Sahara's nighttime coldness was reflected in an increased wake-up frequency, and a longer sleeping time peaked in the third week, probably as a result of overfatigue. MARS2013 was a successful mission with highly motivated participants and minor medical incidents. For future analog missions and possibly long-distance open-space missions, some recommendations in terms of medical and psychological preparedness are made to reduce risks for field crew members and MSC personnel.

A30P α-Synuclein interferes with the stable integration of adult-born neurons into the olfactory network

Impaired olfaction is an early symptom in Parkinson disease (PD), although the exact cause is as yet unknown. Here, we investigated the link between PD-related mutant α-Synuclein (α-SYN) pathology and olfactory deficit, by examining the integration of adult-born neurons in the olfactory bulb (OB) of A30P α-SYN overexpressing mice. To this end, we chose to label one well-known vulnerable subpopulation of adult-born cells, the dopaminergic neurons. Using in vivo two-photon imaging, we followed the dynamic process of neuronal turnover in transgenic A30P α-SYN and wild-type mice over a period of 2.5 months. Our results reveal no difference in the number of cells that reach, and possibly integrate into, the glomerular layer in the OB. However, in mutant transgenic mice these new neurons have a significantly shortened survival, resulting in an overall reduction in the addition of neurons to the glomerular layer over time. We therefore propose unstable integration and impaired homeostasis of functional new neurons as a likely contributor to odour discrimination deficits in mutant α-SYN mice.