Author Interviews, Genetic Research, Ophthalmology / 17.07.2015
MedicalResearch.com Interview with:
Professor Robert E MacLaren MB ChB DPhil FRCOphth FRCS
Nuffield Laboratory of Ophthalmology
Nuffield Department of Clinical Neurosciences
Oxford Biomedical Research Centre, University of Oxford,
Moorfields Eye Hospital & UCL NIHR Biomedical Research Centre for Ophthalmology
London, UK.
MedicalResearch.com Interview with:
Stephen A. Krawetz, Ph.D.
Associate Director C.S. Mott Center for Human Growth and Development,
Charlotte B. Failing Professor of Fetal Therapy and Diagnosis,
Department of Obstetrics and Gynecology,
Center for Molecular Medicine and Genetics,
Wayne State University School of Medicine,
Detroit, MI, 48201
Medical Research: What is the background for this study? What are the main findings?
Dr. Krawetz: The current study developed over approximately the past 20 years of work in my laboratory. In the mid 1990s, along with David Miller, we independently discovered that sperm contain RNA. This was followed by our joint publication in The Lancet that began to describe the RNAs in normal fertile males along with our paper in Nature that showed that RNA was delivered to the oocyte at fertilization. Following these studies we assessed the ability of RNAs to be used as markers of morphologically abnormal sperm (teratozoospermia). My laboratory then had the opportunity to explore the complexity of the population of sperm RNAs using Next Generation Sequencing. We recently began the translation of this work from the bench to bedside which takes us to the current paper in Science Translational Medicine that was a multi-institutional collaborative effort. Members of the team include Dr. Meritxell Jodar, Edward Sendler, Robert Goodrich, from my laboratory, along with Dr. Clifford L. Librach, Dr. Sergey I. Moskovtsev, and Sonja Swanson - CReATe Fertility Center, University of Toronto; Dr. Russ Hauser -Harvard University and Dr. Michael P. Diamond, Georgia Regents University. Here we tackled the issue of idiopathic infertility, that is, unknown infertility, since the couple appears normal in all respects. We specifically framed our study as the contribution of the male and female as a couple towards the birth of a healthy child focusing on male idiopathic infertility within the setting of a Reproductive Clinic. Representative publications from my laboratory that outline this part of my research program appear below.
1) Jodar, M., Sendler, E., Moskovtsev, S. Librach, C., Goodrich, R., Swanson, S., Hauser, R., Diamond, M. and Krawetz, S.A. (2015) Absence of sperm RNA elements correlates with idiopathic male infertility. Science Translational Medicine, 7(295):295re6.
2) Sendler, E., Johnson, G.D., Mao, S., Goodrich, R.J., Diamond, M.P., Hauser, R., and Krawetz, S.A. (2013) Stability, Delivery and Functions of Human Sperm RNAs at Fertilization. Nucleic Acids Research 41:4104-4117. PMID: 23471003
3) Platts, A.E., Dix, D. J., Chemes, H.E., Thompson, K.E., Goodrich, R., Rockett, J. C., Rawe, V.Y., Quintana, S., Diamond, M.P., Strader, L.F. and Krawetz, S.A. (2007) Success and failure in human spermatogenesis as revealed by teratozoospermic RNAs. Human Molecular Genetics. 16:763-773. PMID: 17327269
4) Ostermeier, G.C., Miller, D., Huntriss, J.D., Diamond, M.P. and Krawetz, S.A. (2004) Delivering spermatozoan RNA to the oocyte. Nature 429:154. PMID: 15141202
5) Ostermeier, G.C., Dix, D.J., Miller, D., Khatri, P. and Krawetz, S.A. (2002) Spermatozoal RNA profiles of normal fertile men. The Lancet. 360:773-777. PMID: 12241836
Medical Research Interview with:
Prof. Johan Bosmans
Interventional cardiologist
University Hospital Antwerp, Wilrijkstraat 10, 2650,
Edegem, Belgium
MedicalResearch: What is the background for this study? What are the main findings?
Prof. Bosmans : Transcatheter aortic valve replacement (TAVR) has become standard of care for patients who cannot undergo surgery. With this, it is important to ensure that the risks associated with TAVR be fully understood, and if possible prevented. Even at this stage of the adoption of TAVR, large trials continue to provide information to the clinician about how to select the right patients to ensure the best possible outcomes. The ADVANCE Study is a prospective, multicenter study that evaluated the use of TAVR in 1015 patients at 44 experienced TAVR centers, which was designed to reflect routine clinical practice.
We know that the risk of serious adverse events, such as stroke or transient ischemic attack (TIA), in post-TAVR patients can vary based on the timing before and after the procedure. A patient’s baseline demographics and medical history can affect their risk of procedure-related events as well as long-term outcomes. The manipulations required crossing the aortic valve and appropriately positioning any type of TAV has been thought to be related to procedural stroke events. Therefore, we performed a multivariable analysis looking for predictors of stroke – or stroke and TIA at 3 unique time periods (periprocedural, early and late) following TAVR.
The most striking result from our analyses was that we were not able to identify any predictors of periprocedural (either during the procedure or on the day after) stroke, illustrating this very multifactorial etiology. We were able to show that being female, experiencing acute kidney injury or a major vascular complication positively predicted stroke during the early (2-30 days post procedure) time period. When we combined the outcome of stroke or TIA, we found that a history of prior atrial fibrillation (AF) was also a predictor. The only late predictor (day 31-730 post-procedure) of stroke was a history of coronary artery bypass grafting, which could reflect the patients’ risk of vascular disease.
MedicalResearch.com Interview with:
Dr. Courtney Lyles Ph.D.
Assistant Professor
UCSF School of Medicine
Medical Research: What is the background for this study? What are the main findings?
Dr. Lyles: In our commentary (http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1001852), we describe the Meaningful Use program sponsored by the federal government to incentivize healthcare systems to implement electronic health records (EHRs). This Meaningful Use program also includes financial incentives for healthcare systems who can get substantial proportions of their patient population to access their electronic health records – that is, by logging into an online patient portal website to view medical information like lab results or immunization lists or to perform a healthcare task like requesting a medication refill or messaging their provider. Because there are billions of dollars at stake in this program for EHR implementation, there is a lot of attention on this issue right now. Many thought leaders are discussing how we can transform healthcare by digitizing medical information and connecting with patients in their everyday life outside of office or hospital visits. Portals are key to a lot of changes we might make in healthcare delivery in an attempt to increase convenience and satisfaction for patients. Perhaps most importantly, these online portal websites are also one of the first health technologies that will be relatively uniformly distributed across healthcare settings, from private doctor’s offices to public clinics/hospitals serving vulnerable patient populations.
However, our main message is that we in the medical and healthcare fields should be paying more attention to how patients are able to understand and use the information provided through portal websites. There is a lot of evidence that patients who have lower education/income, are from racial/ethnic minority groups, or have limited health literacy are significantly less likely to use the existing portal websites. There is also evidence that portal websites are not extremely usable or accessible, which is an additional barrier for those with communication barriers like lower literacy or limited English proficiency. Therefore, we don’t want widespread EHR implementation to result in only the most well-resourced individuals gaining the potential benefits of portal access.
MedicalResearch.com Interview with:
Reynold A. Panettieri, Jr., M.D.
Robert L. Mayock and David A. Cooper Professor of Medicine
Pulmonary, Allergy & Critical Care Division
Director, Airways Biology Initiative
Deputy Director, Center of Excellence in Environmental Toxicology
Adjunct Professor, Wistar Institute
Philadelphia, PA 19104-3413
Medical Research: What is the background for this study? What are the main findings?
Dr. Panettieri: Over the past ten years in the US, unconventional gas and oil drilling (hydraulic fracturing) to generate natural gas has markedly increased. In areas with hydraulic fracturing, there is a large increase in truck traffic, noise and potential air and water pollution. Accordingly, residents may experience health consequences from such exposures. We questioned whether proximity to active wells increases hospitalization rates in residents. To address this question, we reviewed all hospitalizations in two counties in Pennsylvania, namely, Bradford and Susquehanna Counties, that experienced a meteoric increase in active wells. In comparison, Wayne County, where there is a moratorium on hydraulic fracturing, is demographically identical to Bradford and Susquehanna Counties and served as a control population. Having examined the 25 most common reasons for admission to the hospital, we determined that cardiovascular hospitalizations as well as neurologic, dermatologic and cancer hospitalizations were associated with living closer to active wells. These data represent some of the first studies to associate active well drilling with hospitalizations in the United States.
MedicalResearch.com Interview with:
H. Joanna Jiang, Ph.D.
Agency for Healthcare Research and Quality
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Jiang: A large proportion of health care resources in the United States are consumed by a relatively small number of individuals, who have been dubbed super-utilizers. Approximately 25% of U.S. health care expenses are incurred by 1% of the U.S. population, and 50% of expenses are incurred by 5% of the population.
Our study found that across all types of payers of medical care (Medicare, Medicaid, and private insurance), super-utilizers on average had approximately 4 times as many hospital stays as other patients, and the 30-day hospital readmission rate for super-utilizers was 4 to 8 times higher than for other patients. Among Medicaid and privately insured patients, super-utilizers had longer hospital stays and higher average hospital costs than other patients.
We also found that patients with multiple chronic conditions, such as diabetes, hypertension, and congestive heart failure, accounted for a greater share of hospital stays among super-utilizers than among other hospitalized patients. Mental health and substance use disorders were among the top 10 principal diagnoses for super-utilizers aged 1 to 64 years regardless of payer.
esearch.com Interview with:
Dr Yeow Tee Goh MBBS
Department of Haematology
Singapore General Hospital
Republic of Singapore
Medical Research: What is the background for this study? What are the main findings?
Dr. Goh: Relapsed or refractory peripheral T-cell lymphoma after conventional chemotherapy is associated with a very poor prognosis and there is currently no recommendation on the standard approach to helping these patients. Novel targeted treatments for relapsed or refractory peripheral T-cell lymphoma such as romidepsin, pralatrexate, belinostat, and brentuximab vedotin has been approved by the US Food and Drug Administration (FDA) based on the results of their Phase II studies. With the exception of the remarkable efficacy of brentuximab vedotin in systemic anaplastic large cell lymphoma (86% of patients responding to treatment), the efficacy of romidepsin, pralatrexate, and belinostat in relapsed or refractory peripheral T-cell lymphoma is only modest with objective response rates between 25% and 29%. To our knowledge, no other clinical study has reported on the use of novel combination of targeted agents in in relapsed or refractory peripheral T-cell lymphoma. In our study, Of 23 patients assessable for responses, 10 (43%, 95% CI 23–63) patients had an objective response, of which 5 were complete responses. The combined proteasome and histone deacetylase inhibitor treatment shows promising activity for patients with peripheral T-cell lymphoma.
MedicalResearch.com Interview with:
Carl "Chip" Lavie MD, FACC FACP, FCCP
Medical Director, Cardiac Rehabilitation and Prevention
Director, Exercise Laboratories
John Ochsner Heart and Vascular Institute
Professor of Medicine
Ochsner Clinical School-UQ School of Medicine
Editor-in-Chief, Progress in Cardiovascular Diseases
Medical Research: What is the background for this study? What are the main findings?
Dr. Lavie: This was a review of the literature on this topic.The main findings are that various lifestyle choices, including obesity, hypertension, metabolic syndrome/diabetes, obstructive sleep apnea , moderate and high alcohol intakes, and sedentary lifestyle but also very high exercise doses are all associated with increased risk of atrial fibrillation (AF).
MedicalResearch.com Interview with:
John A. Elefteriades, MD
William W.L. Glenn Professor of Surgery
Chief of Cardiothoracic Surgery
Director, Aortic Institute at Yale-New Haven
Yale University School of Medicine
Medical Research: What is the background for this study? What are the main findings?
Dr. Elefteriades: The race to map the human genome was declared completed in 2003, at a cost of 3 billion dollars for the international collaborative university group and 300 million dollars for Craig Venter at Celera. Whole exome sequencing can now be performed at a cost of only several thousand dollars per individual. So, whole exome sequencing (also called Next Generation Sequencing) can now be applied to understand and treat diseases of many organ systems.
In this study, we applied whole exome sequencing to study over 100 patients with thoracic aneurysm.
In the late 1990s, both Dr. Diana Milewicz in Texas and our group at Yale had determined that many thoracic aortic aneurysms were genetically transmitted. Dr. Milewicz went on to identify many of the causative mutations. In this study, we were able to look, by whole exome sequencing performed on saliva, for all 21 mutations known to cause thoracic aortic aneurysm--all at one time in one comprehensive genetic test. We were able to protect patients with the most serious discovered mutations by early surgery, the need for which could not otherwise have been apparent.
MedicalResearch.com Interview with:
Sunil Sharma, M.D
Associate professor of pulmonary medicine
Sidney Kimmel Medical College at Thomas Jefferson University
Medical Research: What is the background for this study? What are the main findings?
Dr. Sharma: Obstructive sleep apnea (OSA) is a highly prevalent disorder with significant cardiovascular implications. In this condition the patient may repeatedly quit breathing during sleep, sometimes hundreds of times, leading to loss of oxygen and frequent arousals throughout the night. OSA has been associated with high blood pressure, congestive heart failure, coronary artery disease, arrhythmias and stroke, among other conditions. While overall awareness is improving, the condition is under-recognized in hospitalized patients. Due to multiple co-morbid conditions these patients may be at higher risk for complications. Recent studies have also shown that early recognition of OSA in hospitalized patients may reduce readmission rates. In our study, we used a simple and cost-effective clinical pathway to determine high-risk patients. Of the 149 patient's determined to be high risk by our protocol, 128 (87%) were confirmed with the diagnosis by a polysomnography (gold standard test). Furthermore, data derived from a simple and cost-effective oxygen measuring device (pulse-oximeter) was found to co-relate well with the polysomnography.
MedicalResearch.com Interview with:
Adam Friedman, MD, FAAD
Associate Professor of Dermatology
Residency Program Director
Director of Translational Research
Department of Dermatology
George Washington School of Medicine and Health Sciences
Medical Research: What is the background for this study? What are the main findings?
Dr. Friedman: Acne vulgaris is one of the most common skin disease that affects approximately 40-50 million people in the United States. Acne’s multifactorial etiology, resulting from a mix of androgen-induced elevations in sebum production, abnormal follicular epithelial desquamation and proliferation, hypercolonization of Propionibacterium acnes and host inflammatory reactions, make treatment often times challenging. In looking at the topical therapeutic armament for Acne Vulgaris, which includes benzoyl peroxide, salicyclic acid, topical antibiotics such as clindamycin, and retinoids, all suffer from various related side effects including irritation, erythema, dryness, peeling and scaling, bacterial resistance, and resulting dyschromia from the associated irritation in patients of darker skin types. These adverse events often serve as major limiting factors influencing patient compliance and ultimately impacting efficacy. Therefore new treatments which target all of the complexities of acne are needed, especially given we have not had anything really new brought to market in years. Here, we looked to biology for the answer. Our bodies generate Nitric Oxide, a diatomic lipid loving gaseous molecule, to perform a broad range of biological activities, including but not limited to killing bacteria/fungi/viruses and inhibiting inflammation - key elements in Acne. Its action however is very short lived and therefore using Nitric Oxide as a treatment is difficult as one would need a delivery system that would allow for continued and controlled release. Enter nanotechnology. We designed exceedingly small particles (of note, 1 nanometer = 1 billionth of a meter) which allow for the generation of nitric oxide gas from nitrite salt, and will only release the gas when exposed to moisture over time. The size of the particles also enables them to better interact with their environment, i.e. cells, pathogens, improving their activity as compared to large sized treatments
In this study, we showed that the nitric oxide generating/releasing nano particles effectively killed the organism, P. acnes but was not toxic to both human skin cells and a live vertebrae model (embryonic zebra fish). More importantly, we found that the nano particles inhibits the activation of a newly recognized but exceedingly important inflammatory pathway that is directly tied to the formation of an acne lesion, called the NLRP3 inflammasome. Research has shown that our bodies already regulate this pathway with nitric oxide, and therefore once again, we are looking to biology for answers. As opposed to a drug that may only have one target, the nanoparticles inhibited multiple components/elements of the inflammasome pathway, giving some insight into its potential as a treatment for acne as well as other inflammatory diseases.
MedicalResearch: Why don’t you tell us a little about the background for CASIS?
Response: The mission of NASA is space exploration, while the complementary mission of CASIS is to use ISS (the International Space Station) to better life on earth. CASIS is the non-profit arm of NASA that recruits, selects and manages the scientific research projects conducted on the space station.
[caption id="attachment_15795" align="alignleft" width="500"]
Astronaut Scott Kelly will spend a year in space overseeing multiple research projects.[/caption]
MedicalResearch.com Interview with:
Dr. Vincent L. Cryns MD
Chief of the Division of Endocrinology, Diabetes and Metabolism
Department of Medicine
University of Wisconsin Carbone Cancer Center
University of Wisconsin School of Medicine and Public Health Madison, Wisconsin
Medical Research: What is the background for this study? What are the main findings?
Dr. Cryns: It’s been known for quite some time that many tumors are highly vulnerable to deficiencies in certain amino acids such as methionine, causing tumor cells to stop growing or die. What’s been missing is a molecular explanation for these effects that would allow us incorporate this approach into a rationally designed clinical trial. In our work, we have demonstrated that “starving” triple-negative breast cancer cells of methionine uncovers a “fatal flaw” by increasing the expression of a cell death receptor (TRAIL-R2) that we can activate with a therapeutic antibody to efficiently kill the tumor cells. What’s especially exciting is that we can use a specific diet to metabolically prime cancer cells to respond to a targeted cancer therapy.
MedicalResearch.com Interview with:
Haining Yang MD Ph.D
Associate Professor
Thoracic Oncology Program
University of Hawaii Cancer Center
University of Hawaii, Honolulu, HI
Medical Research: What is the background for this study?
Dr. Yang: Mesothelioma is often caused by asbestos and other carcinogenic mineral fibers. When these fibers lodge in the pleura, mesothelial cells and macrophages try to phagocytize and eliminate them. However, asbestos is very bio-persistent and cannot be eliminated, which caused cells undergoing programmed necrosis that leads to the release of HMGB1 into the extracellular space. HMGB1 is a damage-associated molecular pattern molecule (DAMP) that causes inflammation. Asbestos exposure induces HMGB1 release and chronic inflammatory process that overtime may lead to malignancy. Mesothelioma cells develop out of an environment that is rich in HMGB1 and are often dependent on HMGB1 for their own growth. In fact, most mesothelioma cells actively secrete HMGB1 extra-cellularly to promote their own tumor growth. Accordingly HMGB1 levels are high in the serum of mesothelioma patients (reviewed in Yang and Carbone, Clinical Cancer Res 2013). We tested several anti-inflammatory agents to see if we were able to reduce HMGB1-induced mesothelioma cell growth, and none of them worked except for aspirin, that led us to conduct a series of experiments in vitro and in vivo to test the hypothesis that aspirin inhibits HMGB1 activities, and that by doing so, inhibits mesothelioma growth.
Medical Research: What are the main findings?
Dr. Yang: We found that aspirin inhibits the growth of human mesothelioma cells in a xenograft model, moreover in vitro experiments demonstrated that this effects was specifically mediated via inhibition of HMGB1 and not via COX2 inhibition. We propose that the so far enigmatic anticancer activity of aspirin is mediated, at least partially, via inhibition of HMGB1, and that aspirin may help delay the onset of mesothelioma and may help inhibit the growth of mesothelioma.
MedicalResearch.com Interview with:
Nadereh Pourat, PhD
Professor, Department of Health Policy and Management, UCLA Fielding School of Public Health
Adjunct Professor, UCLA School of Dentistry
Director of Research, UCLA Center for Health Policy Research
Medical Research: What is the background for this study? What are the main findings?
Dr. Pourat: We have succeeded to insure most of the uninsured population in the U.S., but now have to figure out how to reduce costs while improving health. We had the opportunity to examine the role of continuity with a primary care provider, which is one of the pathways that looked promising in improving health and reducing costs. We were evaluating a major demonstration program in California called the Health Care Coverage Initiative (HCCI) and one of the participating counties implemented a policy to increase adherence by only paying for visits if patients went to their assigned providers. We examined what happened to patients who always or sometimes adhered to their provider versus those who never adhered. We found that adherence or continuity reduced emergency department use and hospitalizations. This would lead to savings because of the high costs of these services.
Medical Research: What should clinicians and patients take away from your report?
Dr. Pourat: The study shows that both patients and clinicians would benefit from continuity with the primary care provider. Clinicians can actually make a difference in helping patients: they can teach patients about self-care and help them manage their conditions better. Patients would benefit from following through with treatment plans and experience less medical error and duplication of services which are potentially harmful. Continuity fosters rapport and trust between patients and providers and can be beneficial to both.
MedicalResearch.com Interview with:
Dr. Ankur Pandya Ph.D.
Assistant Professor of Health Decision Science
Department of Health Policy and Management
Harvard T.H. Chan School of Public Health
Boston, MA
Medical Research: What is the background for this study? What are the main findings?
Dr. Pandya: The American College of Cardiology and the American Heart Association (ACC-AHA) cholesterol treatment guidelines were controversial when first released in November 2013, with some concerns that healthy adults would be over-treated with statins.
We found that the current 10-year ASCVD risk threshold (≥7.5%) used in the ACC-AHA cholesterol treatment guidelines has an acceptable cost-effectiveness profile (incremental cost-effectiveness ratio of $37,000/QALY), but more lenient ASCVD thresholds would be optimal using cost-effectiveness thresholds of $100,000/QALY (≥4.0%) or $150,000/QALY (≥3.0%).
Jonathan Cedernaes M.D., Ph.D.
Department of Neuroscience
Uppsala University
Sweden
Medical Research: What is the background for this study? What are the main findings?
Dr. Cedernaes: Sleep is known to facilitate the formation of long-term memory in humans, by transferring newly learned memories from short-term to long-term memory stores. Studies however indicate that even shorter periods of sleep - including naps - can ensure access to different types of memories under normal restful conditions. Furthermore, while some studies have shown that acute sleep loss can exacerbate e.g. physiological responses to acute stress, it it has not been studied whether shortened sleep in combination with acute cognitive stress can have a negative impact on the retrieval of newly learned memories.
With this background in mind, we conducted a study where we aimed to investigate how nocturnal sleep duration impacts this memory transfer, and to what extent long-term memories formed by sleep remain accessible after acute cognitive stress.
We recruited 15 participants who in each of two sessions first underwent a learning session in the evening, during which they learned 15 card pair locations on a computer screen. Then, in one of the two experimental session, subjects slept for half a night (4-hr), instead being able to sleep for a full night (8-hr) in the other session. On the morning after each sleep condition, we had the subjects try to recall as many card pair locations as possible. We found that following half a night of sleep (4-hr), participants were equally able to recall memories for the learned card pair locations, as after a full night of sleep (8-hr). However, we also showed that the ability to retrieve memories following 30 minutes of acute stress, in the morning after these two sleep conditions, was different depending on whether the participants had slept for 8 or 4 hours. Following short sleep, the 30-min long stress exposure reduced the participants' ability to recall the card pair locations that the participants had learned the previous night by around 10%. In contrast, no such stress-induced memory impairment was observed when the same men were allowed to sleep for a full night.
MedicalResearch.com Interview with:
Nora V. Becker MD/PhD candidate
Department of Health Care Management and Economics
Wharton School, University of Pennsylvania, in Philadelphia.
Medical Research: What is the background for this study? What are the main findings?
Response: The Affordable Care Act mandates that private health insurance plans cover prescription contraceptives with no consumer cost sharing. The positive financial impact of this new provision on consumers who purchase contraceptives could be substantial, but it has not yet been estimated. Using a large administrative claims data set from a national insurer, we estimated out-of-pocket spending before and after the mandate. We found that mean and median per prescription out-of-pocket expenses have decreased for almost all reversible contraceptive methods on the market. The average percentages of out-of-pocket spending for oral contraceptive pill prescriptions and intrauterine device (IUD) insertions by women using those methods both dropped by 20 percentage points after implementation of the ACA mandate. We estimated average out-of-pocket savings per contraceptive user to be $248 for the IUD and $255 annually for the oral contraceptive pill.
MedicalResearch.com Interview with:
Diana W. Bianchi, M.D.
Executive Director, Mother Infant Research Institute
Vice Chair for Research and Academic Affairs
Department of Pediatrics
Tufts Medical Center
Medical Research: What is the background for this study? What are the main findings?
Response: Noninvasive Prenatal Testing (NIPT) is the fastest growing genetic test. It has been available since late 2011. Over 2 million tests have been performed worldwide. Cancer in pregnancy is rare, and only occurs in 1 in 1,000 pregnant women. About 0.2 per cent of noninvasive prenatal tests that use sequencing of maternal plasma DNA have a so-called “false positive” result. In most cases this is not an error, but there is a biological explanation for the discrepancy between the abnormal noninvasive prenatal test result and a normal fetal chromosome result obtained from a diagnostic procedure, such as amniocentesis or chorionic villus sampling (CVS). We are very interested in the underlying biological explanations for the false positive cases, and it turns out that a clinically silent tumor in the mother is one of them. The mother’s tumor is shedding DNA into her blood that is detected by the prenatal test.
In a large clinical dataset of over 125,000 pregnant women who had a DNA sequencing screen for fetal chromosome abnormalities there were 10 women who were subsequently found to have cancer. We retrospectively analyzed the DNA sequencing results in 8 of these women and found that they had abnormalities in multiple areas of the genome, suggesting that it was DNA from the tumor that was shed into the maternal blood and being detected by the prenatal screen.
The noninvasive prenatal sequencing test result that was most suggestive of a cancer risk was the presence of more than one aneuploidy. This finding was present in 7 of the 10 women who had cancer.
In three of the eight women we studied it was the abnormal prenatal test result that triggered a subsequent work-up that led to the diagnosis of cancer.
MedicalResearch.com Interview with: Christopher M. Jones, Pharm D., M.P.H. Senior advisor, Office of Public Health Strategy and Analysis Office of the Commissioner, Food...
MedicalResearch.com Interview with:
MB. Pinkham, Clinical Oncology
Christie NHS Foundation Trust
Manchester UK
Medical Research: What is the background for this study?
Response: Brain metastases are a serious complication of advanced malignancy and for most patients the objective is to maximise quality of survival. As treatment decisions become increasingly tailored to the individual, patient-focussed measures of efficacy such as neurocognitive function (NCF) are an important consideration. This is illustrated by the NCCTG N0574 randomised study reported last month at the American Society of Clinical Oncology (ASCO) 2015 Annual Meeting. 208 patients with 1-3 brain metastases each <3cm were randomised to stereotactic radiosurgery (SRS) or SRS with whole brain radiotherapy (WBRT). The addition of WBRT improved intracranial disease control but did not translate into a survival benefit and was associated with a decline in neurocognitive function at 3 months.
The objective of our study was to describe the types of changes in neurocognitive function that can occur, summarise how they are assessed and review approaches used to mitigate their effects. We wanted to provide busy physicians with a clear and comprehensive overview of the topic that could be used to inform clinical decisions.
Medical Research: What are the main findings?
Response: Using sensitive tests, most patients with brain metastases have deficits in neurocognitive function at diagnosis. Evaluating and understanding changes after treatment is complex because neurocognitive function is a dynamic process that is influenced by a long list of inter-related factors.
For patients treated using whole brain radiotherapy alone, worsening neurocognitive function is observed in about two-thirds within 2-6 months. Deficits in verbal memory and fine motor control are most common. It is unclear what proportion relates to treatment toxicity as opposed to disease progression or pre-terminal decline because both are unfortunately also common events during this interval. By contrast, in other patients, NCF improves after WBRT due to treatment response.
For patients with 1-4 brain metastases treated using SRS, the addition of WBRT improves intracranial disease control at the expense of deficits in verbal memory at 4 months but the impact of recurrence and salvage therapy on neurocognitive function later than this is uncertain. Scant data suggests that some deficits in neurocognitive function after WBRT may improve with time in long term survivors. For patients with ≥5 brain metastases, SRS and/or systemic therapies may be considered in select patients instead of upfront whole brain radiotherapy but high quality evidence is lacking.
Advanced radiotherapy technologies, such as hippocampal-sparing WBRT and post-operative cavity SRS, can limit the dose delivered to unaffected areas of the brain in the hope of reducing toxicity. Randomised studies assessing their efficacy and cost-effectiveness in various clinical situations are underway prior to routine use. Small but statistically significant improvements in certain neurocognitive domains can also be achieved using medications such as memantine and donepezil. Preclinical data suggests that some commonly available drugs (such as ramipril, lithium and indomethacin) may have neuroprotective properties following WBRT; further evaluation is warranted.