December 28, 2007, 8:07 AM CT

CT faster more accurate than mammography

Cone-beam breast CT provides exceptional tissue contrast and can potentially reduce examination time with comparable radiation dose to conventional 2D mammography, as per a new study by a team of scientists from the University of Texas M. D. Anderson Cancer Center in Houston.

Cone-beam breast CT employs a large area x-ray beam in conjunction with a flat panel x-ray detector to scan and generate 3D images of the breast. The scanner is placed below a table on which the patient lies prone with the breast protruding through an opening. Only the breast is exposed to radiation resulting in improved image quality and sparing the rest of the patients body from unnecessary radiation exposure. The scan can be completed in less than one minute with a single complete rotation of the x-ray tube-detector gantry around the breast. Unlike conventional CT, the patient is not moved through the gantry during scanning.

For the study, the scientists used cone-beam CT on 12 mastectomy specimens. The scientists discovered that structured noise on cone-beam CT was minimal because of the absence of overlapping tissue; that breast anatomy was well resolved on all images as skin, adipose, and glandular regions; and that microcalcifications within cancers were clearly shown. In addition, they discovered that the detection of cancers based on morphologic assessment of tissue structures could potentially be improved compared with mammography because of the lack of overlapping glandular tissue......... Posted by: Betsy      Read more         Source

December 17, 2007, 8:45 PM CT

Scientists identify and repress breast cancer stem cells

By manipulating highly specific gene-regulating molecules called microRNAs, researchers at Cold Spring Harbor Laboratory (CSHL) report that they have succeeded in singling out and repressing stem-like cells in mouse breast tissue cells that are widely thought to give rise to cancer.

If certain forms of breast cancer do indeed have their origin in wayward stem cells, as we believe to be the case, then it is critical to find ways to selectively attack that tumor-initiating population, said Gregory Hannon, Ph.D., CSHL professor and Howard Hughes Medical Institute Investigator. Hannon also is head of a lab focusing on small-RNA research at CSHL and corresponding author of a paper reporting the new research, reported in the latest issue of Genes and Development.

We have shown that a microRNA called let-7, whose expression has previously been linked to tumor suppression, can be delivered to a sample of breast-tissue cells, where it can help us to distinguish stem-like tumor-initiating cells from other, more fully developed cells in the sample. Even more exciting, we observed that by expressing let-7 in the sample, we were able to attack and essentially eliminate, very specifically, just that subpopulation of potentially dangerous progenitor cells.

The study was done in collaboration with Senthil Muthuswamy Ph.D., an expert in breast cancer research who heads a CSHL lab focusing on understanding the changes in the biology of breast epithelial cells during the initiation and progression of cancer. Dr. Muthuswamy emphasized that a key ingredient that made this study successful is the use of a mouse breast-derived model cell system called COMMA-1D that not only includes differentiated cells but also stem-like progenitors, in varying stages of maturity, or differentiation......... Posted by: Betsy      Read more         Source

December 13, 2007, 9:58 PM CT

Stem cell transplant for breast cancer

High-dose chemotherapy and autologous stem cell transplantation, the controversial, arduous, yet once-popular combination therapy that fell out of favor as a treatment for breast cancer, has proven not to be beneficial as an adjuvant treatment for women with node-positive disease, as per an expansive analysis conducted by scientists at The University of Texas M. D. Anderson Cancer Center.

In a review of 15 randomized high-dose chemotherapy studies conducted around the world between 1988 and 2002, the researchers from M. D. Anderson, in collaboration with the European Blood and Marrow Transplant Group, report that while there was a slight benefit on relapse-free survival, there was no benefit to overall survival. Donald Berry, Ph.D., professor and head of the Division of Quantitative Sciences, presented the findings today at the 30th annual San Antonio Breast Cancer Symposium.

"Of all cancers, breast cancer is one of the most sensitive to therapy, resulting in a dramatic mortality decrease in the U.S. in recent years," says Berry. "Frequently, in recent breast cancer history, when we have run studies of adjuvant treatment for node- positive breast cancer, the findings have shown that an innovation indeed delays recurrence and prolongs survival. For example, we've shown that increasing doses of the chemotherapy regimen FAC within the standard dose range improves overall survival and disease-free survival. We've shown the same for the addition of paclitaxel. We've also proved that dose density, in terms of delivery every two weeks versus every three weeks, improves overall survival......... Posted by: Betsy      Read more         Source

December 11, 2007, 10:40 PM CT

Accuracy of diagnostic mammograms varies by radiologist

For women with breast symptoms such as lumps, the ability of diagnostic mammograms to detect breast cancer accurately depends strongly on which radiologist reads them, as per a Group Health study published online on December 11 in the Journal of the National Cancer Institute.

When a woman gets a mammogram, she wants to know that if she has breast cancer, the mammogram will be likely to detect it, said study leader Diana Miglioretti, PhD, an associate investigator at Group Health Center for Health Studies. This is particularly important when the woman has a breast concern such as a lump.

Ideally, this ability to accurately detect cancer (known as sensitivity) would be consistently high, with few false-positivesbiopsies performed despite the absence of cancer. And it wouldnt depend on which radiologist was reading the mammograms. But thats not what we found, she added.

The research team examined how well 123 radiologists interpreted nearly 36,000 diagnostic mammograms done to evaluate breast problems, such as lumps, from 1996 through 2003 at 72 U.S. facilities, including six from Group Health, that contribute data to the Breast Cancer Surveillance Consortium.

For different radiologists, sensitivity ranged from 27 percent to 100 percent; and false-positives, from 0 to 16 percent. These differences were only partially explained by the characteristics of the patients and the experience of the radiologists......... Posted by: Betsy      Read more         Source

December 9, 2007, 5:17 PM CT

BRCA1 mutations cause breast cancer

An international team of scientists led by Columbia University Medical Centers Herbert Irving Comprehensive Cancer Center and Swedens Lund University has, for the first time, revealed how mutations in the BRCA1 gene lead to breast cancer. Findings show that one way BRCA1 mutations cause cancer is by knocking out a powerful tumor suppressor gene known as PTEN.

The new study will be published online on the Nature Genetics website on Dec. 9, 2007: http://www.nature.com/ng. It will appear in the January print issue of this journal. The study was led by Ramon Parsons, M.D., Ph.D., the Avon Foundation Professor of Medicine and Pathology at Columbia University College of Physicians and Surgeons and ke Borg, Ph.D., professor of oncology at Lund University. The papers first author was Lao Saal, Ph.D. (now finishing his medical degree at Columbia University College of Physicians and Surgeons).

These findings are exciting because ever since the link was established between BRCA1 and breast cancer more than 10 years ago, we have been frustrated by our lack of understanding about how mutations in this gene cause breast cancer. We have been stymied by our limited resources to treat these cancers, which are linked to very poor prognoses. Now that we know that PTEN is involved, we finally have a target for treatment for these cancers, said Dr. Parsons, the studys corresponding author. Dr. Parsons is director of the Avon Foundation Breast Cancer Research Laboratory and director of the Breast Cancer Program of the Herbert Irving Comprehensive Cancer Center at Columbia University Medical Center and NewYork-Presbyterian Hospital......... Posted by: Betsy      Read more         Source

November 28, 2007, 10:02 PM CT

Stereo Mammography Improves Cancer Detection

A new radiological diagnostic tool called stereo mammography allows clinicians to detect more lesions and could significantly reduce the number of women who are recalled for additional tests following routine screening mammography.

The findings from a clinical trial underway at Emory University were presented today at the annual meeting of the Radiological Society of North America held in Chicago.

In the study, stereoscopic digital mammography reduced false-positive findings by 49 percent in comparison to standard digital mammography, and reduced missed lesions by 40 percent, as per Dr. Carl DOrsi, MD, professor of radiology, Emory University School of Medicine, and director of breast imaging.

This finding is very significant because it shows the technology cuts by almost half the number of women who are recalled for additional tests, reduces the number of false positives that typically occur in standard mammograms and eliminates significant anxiety in patients and their loved ones, says Dr. DOrsi.

Standard mammography is widely considered to be one of the most difficult exams to read because lesions may be disguised by normal tissue," says Dr. D'Orsi. "At the same time, false-positives can also occur because of the two dimensional images provided by the existing technology......... Posted by: Betsy      Read more         Source

November 15, 2007, 9:59 PM CT

Similarities In Dog, Human Breast Cancer

Pre-cancerous mammary lesions in dogs and humans display a number of of the same characteristics, a discovery that could lead to better understanding of breast cancer progression and prevention for people and pets, said a Purdue University scientist from the School of Veterinary Medicine.

A group of researchers including Sulma Mohammed have found similarities between non-malignant lesions that are considered to carry risk for developing breast cancer in both canines and humans. Breast cancer is the second leading cause of cancer deaths in women.

"Dogs develop these lesions spontaneously in contrast to other available models and are exposed to the same environmental risk factors as humans," said Mohammed, an associate professor in comparative pathobiology. "These shared features make the dog an ideal model to compare the breast lesions that will progress to cancer and those that will regress. Such a model will facilitate customized therapy and prevention strategies." .

Due to the success of mammographic screening and awareness by women, abnormal cell growth within breast tissues is frequently diagnosed, Mohammed said. These intraepithelial lesions are recognized risk factors for invasive cancer, and their presence affects patient management decisions......... Posted by: Betsy      Read more         Source

November 13, 2007, 9:39 PM CT

Proteins As urvival Markers in Some Breast Cancers

New research suggests that the presence or absence of two proteins may be important markers for long-term survival in some breast-cancer patients.

One of the proteins, called ErbB-4, is important for the growth and differentiation of several types of cells in the body. The second protein, called Wwox, is a tumor suppressor - it helps prevent cells from becoming malignant - and it is missing in a number of breast cancers. Researchers don't yet understand how it works.

The research shows that the two proteins work together, and that their absence is linked to shorter survival in breast cancer. Furthermore, the study shows that Wwox keeps ErbB4 on the cell surface, and that this is linked to better survival.

The study was done by scientists at the Ohio State University Comprehensive Cancer Center in collaboration with scientists in Finland, and it was published in a recent issue of the journal Cancer Research.

"Our findings suggest that the interaction of these two proteins is clinically important in breast cancer," says first author Rami I. Aqeilan, research assistant professor of molecular virology, immunology and medical genetics at Ohio State's Comprehensive Cancer Center.

"The findings must be verified, but they suggest that we can use these proteins as clinical markers that predict better survival. Therapeutically, perhaps we can design drugs or inhibitors that interact with ErbB-4 to help control the growth of these tumors."........ Posted by: Betsy      Read more         Source

November 13, 2007, 9:24 PM CT

Simpler way to assess breast cancer risk

A new, simpler model for predicting breast cancer risk in postmenopausal women appears to be as accurate as a more complicated method currently used to decide if women would benefit from medicine to reduce their risk of getting cancer, as per research published recently in the Journal of the National Cancer Institute.

A team of scientists led by Rowan T. Chlebowski, a lead investigator at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LA BioMed), sought a simpler method for measuring breast cancer risk so women and their doctors could easily determine when the women would be likely to benefit from tamoxifen therapy for reducing their chances of getting breast cancer.

"For the first time, a postmenopausal woman can use a simple model and determine by herself if she is at increased risk of getting breast cancer, said Dr. Chlebowski. She could then raise this issue with her health care provider because interventions to reduce her risk of breast cancer are now available".

Using data from the Womens Health Initiative, a 15-year research program involving 161,808 postmenopausal women and funded by the National Institutes of Health, the scientists found postmenopausal women were at an increased risk of developing breast cancer if they were: 55 years of age or older and had either had a breast biopsy at any time, regardless of findings, or had a first-degree relative (mother, sister or daughter) who had breast cancer diagnosed at any age......... Posted by: Betsy      Read more         Source

November 7, 2007, 8:59 PM CT

Extracts of catfish caught in polluted waters

Exposing estrogen-sensitive breast cancer cells to extracts of channel catfish caught in areas with heavy sewer and industrial waste causes the cells to multiply, as per a University of Pittsburgh study being presented at the annual meeting of the American Public Health Association in Washington, D.C. The abstract, number 159141, will be presented at a special session on Contaminants in Freshwater Fish: Toxicity, Sources and Risk Communication, at 8:30 a.m., Wednesday, Nov. 7.

The study, which tested extracts from channel catfish caught in the Allegheny and Monongahela rivers near Pittsburgh, suggests that the fish, caught in areas of dense sewer overflows, contain substances that mimic the actions of estrogen, the female hormone. Since fish are sentinels of water quality, as the canary in the coal mine is a sentinel of air pollution, and can concentrate fat soluble chemicals from their habitats within their bodies, these results suggest that pharmaceutical estrogens and xeno-estrogenic chemicals, those that mimic estrogens in the body, may be making their way into the regions waterways.

We believe there are vast quantities of pharmaceutical and xeno-estrogenic waste in outflows from sewage therapy plants and from sewer overflows, and that these chemicals end up concentrated and magnified in channel catfish from contaminated areas, said Conrad D. Volz, Dr.P.H., M.P.H., principal investigator, department of environmental and occupational health, University of Pittsburgh Graduate School of Public Health. Sewer overflows result from inadequate sewer infrastructure, which releases raw, untreated sewage directly into area rivers during wet weather, as per Dr. Volz. In Pittsburgh alone, 16 billion gallons of raw, untreated sewage are deposited into area rivers every year with major implications for public health......... Posted by: Betsy      Read more         Source