Scientists Urge Major Changes for Cancer Screening and Treatment

The "Viewpoint" article will be published online Monday, July 29, in the Journal of the American Medical Association.

When cancer screening programs were widely initiated three decades ago, medical knowledge of the disease was more simplistic. The intent was to detect cancer at its earliest stages to reduce illness and mortality, but in fact early diagnosis has not led to a proportional decline in serious disease and death, the scientists write in the JAMA commentary.

Instead, screening programs are identifying not only malignant cancers, but also slow-growing, low-risk lesions, and sweeping them into the same treatment process. As a result, patients are being diagnosed and treated for forms of cancer that might never actually harm them - a phenomenon that''s been termed overdiagnosis, which translates to "too much medicine."

Now, with the advancement of scientific understanding of the biology of cancer, the authors say it is time for significant changes in practice and policy.

"By recognizing that cancer is not one disease, but a number of different diseases, we can individualize our treatment based on biology and avoid overtreatment," said panel chair Laura J. Esserman, MD, MBA, director of the Carol Franc Buck Breast Care Center at the UCSF Helen Diller Family Comprehensive Cancer Center. "The goal going forward is to personalize screening strategies, and focus screening policies on the conditions that are most likely to result in aggressive illness and death."

The authors recommend creation of a new classification for tumors that are indolent (unlikely to cause patients harm). For example, ductal carcinoma of the breast -- currently considered the earliest form of breast cancer -- would no longer be called cancer. The authors also call for the formation of registries for lesions with low potential for malignancy, and for a multidisciplinary approach across pathology, imaging, surgery and other medical specialties "to revise the taxonomy of lesions now called cancer."

The key, they say, is to improve screening strategies to avoid overtreating tumors that would not be lethal, or that would not even have come to medical attention.

"Although our understanding of the biology of cancer has changed dramatically, perceptions on the part of the public, and among many physicians, have not yet changed," Esserman said. "Cancer is still widely perceived as a diagnosis with lethal consequences if left untreated."

The JAMA article is comprised of recommendations from a working group formed last year during a meeting convened by the National Cancer Institute. The group was charged with developing a strategy to improve current approaches to cancer screening and prevention.?

The commentary was co-written by Ian M. Thompson, MD, professor at the University of Texas Health Science Center at San Antonio; and Brian Reid, MD, PhD, director of the Seattle Barrett''s Esophagus Program and member of the Human Biology Division at the Fred Hutchison Cancer Research Center in Seattle.

The three authors served as chairs of the NCI working group.

Overdiagnosis is occurring across many medical conditions, but is particularly common in breast cancer, lung cancer, prostate, thyroid cancer and melanoma, said the authors.

They cite DCIS, or ductal carcinoma of the breast, and Barrett''s esophagus as illustrations of how the detection and surgical removal of what have been called precancerous lesions have failed to lead to lower rates of invasive cancer.

By contrast, the authors said, colon and cervical cancer serve as examples of "effective screening programs in which early detection and removal of precancerous lesions have reduced incidence as well as late-stage disease."?

Cancer screening should have three important missions, the authors write: To detect disease that would ultimately harm the patient; to uncover tumors that benefit from intervention; and to detect disease that is more likely to be cured or better treated when spotted early.

Optimal screening frequency depends on a cancer''s growth rate. If a cancer is fast growing, screening is less likely to be effective. "If a cancer is slow growing but progressive, with a long latency and a precancerous lesion, screening is ideal and less frequent screening (eg.10 years for colonoscopy) may be effective," the authors said.

Source-Newswise

View the original article here

Research Says Brain Epigenome Changes from Birth to Adolescence

Today, an article published in Science in collaboration with the group of Manel Esteller, Director of Epigenetics and Cancer Biology Biomedical Research Institute (IDIBELL), ICREA researcher and Professor of Genetics at the University of Barcelona, gives us an important clue to understanding this process.

Researchers have discovered that people's frontal cortex (the part of the brain responsible for the conduct and the acquisition of new information) experiences a significant change from birth to the end of adolescence. The epigenome is transformed.

The study analyzes the epigenome of newborns, teenagers aged 16, and adults aged 25 and 50 in the United States and in Catalonia (Spain).

Epigenome

Epigenome is the set of chemical signals responsible for turning on or off genes in our DNA. The discovery published in Science shows that one of these epigenetic signals, methylation of genetic material, is progressively increased until the end of adolescence and entry into adulthood.

"The results of the study show that DNA methylation has a key role in shaping the communication spaces between neurons (synapses)", explains Esteller. "The brain is divided into white matter (glial) and gray matter (neurons) with several cell types with different functions. DNA methylation patterns distinguish genes with cell-type specific activity. Even in the gray matter, there are cell subtypes such as pyramidal neurons and GABA neurotransmitter producers that have specific subpatterns of DNA methylation."

Source-Eurekalert

View the original article here

Changes in Hyaluronan Metabolism Key in Adaptation of Keratinocytes to Radiation Injury: Research

by Rukmani Krishna on? July 05, 2013 at 10:53 PM General Health News Epidermis as the outermost layer of skin is crucial in forming a permeability barrier and protection against various environmental agents. Thus, investigating the biology of its most important cell type, the keratinocyte, is key to understanding the effects of solar ultraviolet radiation in skin, and helps design effective means of protection against excessive exposure. UV irradiation increases the expression of hyaluronan, which is an important carbohydrate of the extracellular matrix as shown previously by both cell culture and in vivo animal models.
Hyaluronan is also clearly increased in tissue sections from early stage squamous cell carcinomas, one important risk factor of which is exposure to UV radiation.Hyaluronan metabolism in cells and tissues has long been a special area of interest in the research group of Professors Raija and Markku Tammi at the Institute of Biomedicine, University of Eastern Finland. One important target tissue and focus in these studies has been the skin.

In a recent paper published in The Journal of Biological Chemistry, the group demonstrated that already fairly low doses of UVB activate the accumulation and degradation of hyaluronan. This occurs in both simple monolayer cultures of keratinocytes and a stratified, three-dimensional model that mimics normal skin epidermis. As intracellular signalling pathways are activated, the hyaluronan producing enzymes (Has1-3) and hyaluronan synthesis are upregulated. Particularly, it was shown that Has1 and Has2 are regulated by the MAP kinase p38, and Has3 by the calcium-dependent protein kinase CaMKII.Since hyaluronan content and the absolute and relative quantities and activity of the hyaluronan synthases depend on the tissue context and physiological conditions, it's crucial to understand the underlying regulatory mechanisms.

In this study, the significantly upregulated hyaluronan metabolism in the keratinocytes seemed to be dependent specifically on the Has3 enzyme. Blocking its expression with a specific siRNA reversed the UVB-induced hyaluronan production nearly to the level of the control cells. The results thus strongly indicate that epidermal keratinocytes exposed to UVB specifically activate their hyaluronan synthesis by regulating the HAS-enzymes via at least two different signalling pathways. This may be one mode for the cells to adapt to radiation damage. Even though more research is warranted, the new data further our understanding about the significance of hyaluronan for keratinocyte function under environmental stress. This activation of hyaluronan metabolism after excessive UVB exposure may also prove to be a target for regulation when trying to control and understand tissue malignancy and pre-cancerous alterations.

Source-Eurekalert

var xmlHttpvar imgpath,imagefunction RefreshImage(ImageId){image=document.getElementById(ImageId);//alert(ImageId);xmlHttp=GetXmlHttpObject();if (xmlHttp==null) { alert ("Your browser does not support AJAX!"); return; } var url="http://www.medindia.net/captcha/captcha.asp";url=url+"?x="+Math.random();imgpath=url;xmlHttp.onreadystatechange=stateChangedReg;xmlHttp.open("GET",url,true);xmlHttp.send(null);} function stateChangedReg(){if (xmlHttp.readyState==4){image.src = imgpath;}}function RequestCode(){xmlHttp=GetXmlHttpObject();if (xmlHttp==null) { alert ("Your browser does not support AJAX!"); return; } var url="http://www.medindia.net/captcha/reqimgvalue.asp";url=url+"?x="+Math.random();xmlHttp.onreadystatechange=stateChangedReq;xmlHttp.open("GET",url,true);xmlHttp.send(null);} function stateChangedReq(){if (xmlHttp.readyState==4){var seccode=xmlHttp.responseText;if(seccode==document.getElementById("scode").value){//alert(seccode + "same value");}else{document.getElementById("scode").value=xmlHttp.responseText;}}}function GetXmlHttpObject(){var xmlHttpNew=null;try { // Firefox, Opera 8.0+, Safari xmlHttpNew=new XMLHttpRequest(); }catch (e) { // Internet Explorer try { xmlHttpNew=new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { xmlHttpNew=new ActiveXObject("Microsoft.XMLHTTP"); } }return xmlHttpNew;}function GetXmlHttpObject(){var xmlHttp=null;try { // Firefox, Opera 8.0+, Safari xmlHttp=new XMLHttpRequest(); }catch (e) { // Internet Explorer try { xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); } }return xmlHttp;} function fnsearch(){day1 = document.search.SelDay.value;month1 = document.search.SelMonth.value;year1 = document.search.SelYear.value;tmpdate=month1+"/"+day1+"/"+year1 fromdate=new Date(year1,month1-1,day1)if (!((fromdate.getDate()==day1)&&(fromdate.getMonth()+1==month1)&&(fromdate.getFullYear()==year1))){alert("Please Select a valid Date")document.search.SelDay.focus();return false;}tmpcatid=document.search.ncategoryid.value;tmpkeyword=document.search.keyword.value;document.search.action="http://www.medindia.net/news/newsday_list.asp?ddate="+tmpdate+"&ncategoryid=" +tmpcatid +"&keyword=" +tmpkeywordreturn true;}News Categories:?? Latest Health News Popular News AIDS/HIV News Alcohol & Drug Abuse News Alternative Medicine News Anti-Aging News Bird Flu News Cancer News Celebrity Health News Chikungunya News Child Health News Cholesterol News Clinical Trials News Corporate News Dengue News Dental News Diabetes News Diet & Nutrition News Drug News Education News Environmental Health General News Genetics & Stem Cells News Health Insurance News Heart Disease News Hospital News Hypertension News Indian Health News Lifestyle News Medical Gadgets Medical PDA News Medico Legal News Men?s Health News Mental Health News News on IT in Healthcare Nursing Profession News Obesity News Organ Donation News Research News Respiratory Disease News Senior Health News Sexual Health News Tropical Disease News Weight Loss Women Health News

View the original article here