January 29, 2007, 9:34 PM CT

Why Breast cancer incidence is decreasing?

Breast cancer incidence in the United States has dropped sharply and this decline might be due to the fact that millions of older women have stopped using hormone replacement therapy, according to research presented here at the 29th Annual San Antonio Breast Cancer Symposium.

The researchers reported that there was an overall 7% relative decline in breast cancer incidence between 2002 and 2003 and that the steepest decline (12%) occurred in women aged between 50 and 69 diagnosed with estrogen receptor-positive breast cancer. ER-positive breast cancer depends on hormones for tumor growth, according to the report.

From their data, the researchers concluded that as many as 14,000 fewer women were diagnosed with breast cancer in 2003 than in 2002, a year in which the American Cancer Society estimated 203,500 new cases of breast cancer were diagnosed.

"It is the largest single drop in breast cancer incidence within a single year I am aware of," said Peter Ravdin, MD, PhD, a research professor in the department of biostatistics at the University of Texas MD Anderson Cancer Center in a press release.

"Something went right in 2003, and it seems that it was the decrease in the use of hormone therapy, but from the data we used we can only indirectly infer that is the case," he said. "But if it is true, the tumor growth effect of stopping use of HRT is very dramatic during a short period of time, making the difference between whether a tumor is detected on a mammogram or not in 2003," Ravdin said.........

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January 24, 2007, 6:17 PM CT

Estrogen Interferes With Breast Cancer surveillance

Estrogen is known to enhance the growth and migration of breast cancer cells. Now researchers at the University of Illinois at Urbana-Champaign have found that estrogen also can shield breast cancer cells from immune cells.

According to a research findings published online this week in Oncogene, the researchers report that estrogen induces the expression of an inhibitor that blocks immune cells' ability to kill tumor cells. This is the first study to identify estrogen's role in shielding breast cancer cells from the action of immune cells.

The researchers analyzed estrogen's role in the cascade of events that occurs when immune cells, called natural killer cells, encounter a tumor cell. Under normal conditions, natural killer cells release granules that contain enzymes, called granzymes, which enter and kill the tumor cell.

The research team found that when estrogen binds to an estrogen receptor the complex promotes production of a granzyme inhibitor, proteinase inhibitor 9 (PI-9). The inhibitor binds the granzyme, preventing it from initiating the molecular cascade that kills tumor cells.

"It wasn't known that estrogen could do this in breast cancer cells," said principal investigator David J. Shapiro, a professor of biochemistry in the School of Molecular and Cellular Biology. "The amounts of estrogen required to do this are quite small".........

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January 24, 2007, 6:05 PM CT

Turning A Cellular Sentinel Into A Cancer Killer

Howard Hughes Medical Institute scientists have developed two strategies to reactivate the p53 gene in mice, causing blood, bone and liver tumors to self destruct. The p53 protein is called the "guardian of the genome" because it triggers the suicide of cells with damaged DNA.

Inactivation of p53 can set the stage for the development of different types of cancer. The researchers' findings show for the first time that inactivating the p53 gene is necessary for maintaining tumors. While the scientists caution that cancers can mutate to circumvent p53 reactivation, they believe their findings offer ideas for new approaches to cancer treatment.

The research was carried out independently by two Howard Hughes Medical Institute (HHMI) research teams led by Tyler Jacks at the Massachusetts Institute of Technology and Scott Lowe at Cold Spring Harbor Laboratory. Both papers were published online January 24, 2007, in advance online publication articles in the journal Nature. Eventhough scientists have long known that p53 inactivation plays a central role in the development of cancer, little was known about whether p53 inactivation played a role in maintaining cancers. And scientists were not sure whether switching p53 back on in tumor cells would have any therapeutic effect.........

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January 12, 2007, 4:44 AM CT

New Radiation Technique To Treat Liver Cancer

Physicians at Mayo Clinic are now using tiny glass bubbles filled with radioactive material to deliver high doses of tumor-killing radiation directly to liver tumors. They say the procedure is better tolerated than other forms of intra-arterial liver cancer treatments, and may be the best option for some patients who aren't candidates for other treatments, including surgery or liver transplantation.

The technique, called either radioembolization or intra-arterial brachytherapy, uses the blood supply to send the little spheres, smaller in diameter than a human hair, into the newly formed, microscopic vessels that feed cancer. They eventually become lodged at the tumor sites where they deliver a high dose of radiation.

And because these liver tumors use a supply of blood that is largely separate from the blood that nourishes normal liver tissue, few of the microspheres end up in the healthy liver, Mayo clinicians say.

"The technique is a clever way of exploiting the differences in blood supply between the liver tumor and normal liver tissue," says Mayo Clinic interventional radiologist Ricardo Paz-Fumagalli, M.D. He, along with Mayo Clinic radiation oncologists, deliver the therapy to patients.

There are two primary blood vessels that bring blood to the liver. Normal liver tissue receives about three-fourths of its blood supply from the portal vein and only about one-fourth from the hepatic artery and its branches, explains Paz-Fumagalli. Liver tumors, on the other hand, get most of their life-sustaining blood supply from the hepatic artery and absorb a greater proportion of the radioactive microspheres. "So if you give a treatment through the arteries, it more specifically hits the tumor, and the normal liver is relatively spared," he says.........

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January 10, 2007, 9:56 PM CT

Online Prayer May Help Breast Cancer Patients

Interesting news on breast cancer reported by Reuters and CNN.

Praying online in a support group may help women with breast cancer cope with the disease more effectively, a new study shows.

Dr. Bret Shaw of the University of Wisconsin-Madison and his colleagues observed that patients with breast cancer who used a higher percentage of religion-related words in their communications with an Internet support group had lower levels of negative emotions, better functional well-being, and more confidence in their ability to deal with their illness.

"Patients with breast cancer who want to pray can use online support groups as a place to cope with their illness with other people going through similar situations," Shaw told Reuters. "Our data suggest that this might make you feel better".

Shaw decided to launch the study after observing how common it was for people to use prayer in online support groups. "We noticed a lot of people were exchanging prayers on line, praying for themselves and other group participants," he said.

However, he added that "some women were so kind of turned off by the overly religious tone of the groups that they did not want to participate".

To investigate the health, social and emotional effects of online prayer for women with breast cancer, Shaw and his team loaned a group of women computers associated with the Web. They also provided training on computer and Internet use. The women were surveyed at the study's outset and again after four months of support group participation.........

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January 10, 2007, 4:31 AM CT

Cancer-related Gene Critical For Placenta Development

An important cancer-related gene may play a critical role in the development of the placenta, the organ that controls nutrient and oxygen exchange between a mother and her fetus during pregnancy, and perhaps in miscarriages.

Those conclusions come from a new study of the retinoblastoma (Rb) gene in mice. In humans, this gene, when mutated, raises the risk of a rare cancer of the eye called retinoblastoma. Two decades ago, it was identified as the first tumor-suppressor gene, a class of genes that protects cells from becoming malignant. It has since been shown to be inactivated in a number of cancers.

In this study, scientists shut off the Rb gene in stem cells that give rise to most of the placenta, resulting in an abnormal placenta and death of the embryos.

The findings provide new insights into development of the placenta and into how the Rb gene blocks tumor growth.

They also raise the possibility that this important tumor-suppressor gene might play a role in miscarriages.

The study, led by scientists at the Ohio State University Comprehensive Cancer Center, is reported in the January 2007 issue of the journal Genes and Development.

"Our findings strongly suggest that the Rb gene is important in the development of the placenta, but they have other important implications, as well," says principal investigator Gustavo Leone, assistant professor of molecular virology, immunology and medical genetics and a researcher with Ohio State's Comprehensive Cancer Center and human cancer genetics program.........

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January 8, 2007, 9:28 PM CT

Nanoparticles Pack Multiple Assault On Tumors

A collaborative team led by Erkki Ruoslahti, M.D., Ph.D., of the Burnham Institute for Medical Research at UC Santa Barbara (Burnham) has developed nanoparticles that seek out tumors and bind to their blood vessels, and then attract more nanoparticles to the tumor target. Using this system the team demonstrated that the homing nanoparticle could be used to deliver a "payload" of an imaging compound, and in the process act as a clotting agent, obstructing as much as 20% of the tumor blood vessels. These findings are pending publication in the Proceedings of the National Academy of Sciences and will be made available at the journal's website during the week of January 8, 2007.

The promise of nanomedicine is based on the fact that a particle can perform more functions than a drug. Multifuncionality is demonstrated in the current study, in which researchers from Burnham, UC San Diego, and Massachusetts Institute of Technology designed a nanoparticle that combined tumor-homing, self-amplification of the homing, obstructing tumor blood flow, and imaging.

Using a screening technique developed previously in Ruoslahti's laboratory, the group identified a peptide that homed to the blood vessels, or vasculature, inside breast cancer tumors growing in mice. The peptide was comprised of five amino acids: Cysteine-Arginine-Glutamic acid-Lysine-Alanine, abbreviated CREKA.........

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December 26, 2006, 8:00 PM CT

Profiling Of Cancer Genes

A research team at UT Southwestern Medical Center has for the first time identified several genes whose expression is lost in four of the most common solid human cancers - lung, breast, prostate and colon cancer.

The findings, which researchers say could form the basis for a new early detection screen for certain cancers, are published recently in the online journal Public Library of Science Medicine.

The expression of genes that inhibit cancer development, so-called tumor suppressor genes, is often lost in tumor cells. This can occur through a mutation in the gene's DNA sequence or through deletion of the gene. Loss of tumor suppression function also can occur in a process called methylation, where a chemical called a methyl group is attached to a DNA region near the gene and prevents it from being activated, essentially "silencing" the gene.

"These results show the power of studying tumors on a genome-wide basis, looking at many genes at the same time," said Dr. John Minna, the study's senior author and director of the W.A. "Tex" and Deborah Moncrief Jr. Center for Cancer Genetics and the Nancy B. and Jake L. Hamon Center for Therapeutic Oncology Research at UT Southwestern.

In an effort to identify new tumor-suppressor genes that might be important to lung and breast cancer development, the UT Southwestern team examined which genes are active in those kinds of tumors and compared them to gene expression profiles from normal lung epithelial cells. The researchers then examined the gene expression profiles of these various cell types before and after treatment with a drug that inhibits methylation.........

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December 18, 2006, 7:43 PM CT

Characteristics Of Fast-growing Skin Cancers

What are the characteristics of a fast-growing melanoma? Scientists have identified several characteristics that would make it easy to identify fast-growing melanomas. A melanoma lesion is more likely to go faster if they are thicker, symmetrical, elevated, have regular borders or have symptoms. These findings are from the results of a recent study that is reported in the latest issue JAMA/Archives journals. The study also observed that rapidly progressing melanoma is more likely to occur in elderly men and individuals with fewer moles and freckles, and its cells tend to divide more quickly and have fewer pigments than those of slower-growing cancers.

"Anecdotal experience suggests that there is a form of rapidly growing melanoma, but little is known about its frequency, rate of growth, or associations," the authors write as background information in the article. One previous study suggested that how quickly a melanoma grew predicted how likely the patient was to relapse at one year or to survive without relapsing. Other research indicates that different types of melanoma grow at different rates; for instance, an aggressive type known as nodular melanoma grows more quickly than any other kind.

Wendy Liu, M.B.Ch.B., Ph.D., Peter MacCallum Cancer Center, East Melbourne, Australia, and colleagues investigated melanoma growth rate in 404 consecutive patients (222 male, 182 female, average age 54.2) with invasive melanoma. Participants' skin was examined by a dermatologist and information about such characteristics as the number of typical and atypical moles was recorded. In addition, the patients were interviewed as soon as possible after diagnosis and preferably with a friend or family present. The researchers gathered information about demographics, skin cancer risk factors, the characteristics of the tumor and who first detected the cancer-the patient, a family member or friend, or a physician.........

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December 15, 2006, 4:28 AM CT

Potential For Breast Cancer Spread

Scientists are always trying to find ways to predict the behaviors of cancer cells. One area of interest is to identify proteins and other biomarkers linked to the potential of cancer spread. Over the years a number of biomarkers were identified and the scientists are continuing to uncover more of these. Recently scientists observed that expression of two different proteins taken from primary tumor biopsies is highly linked to spread of breast cancer to nearby lymph nodes. Researcher say this protein profile could help identify at an early stage those patients whose disease is likely to metastasize.

In the December 15 issue of Cancer Research, the scientists say over-expression of one unidentified protein and under-expression of another is 88 percent accurate in identifying breast cancer that has spread in a group of 65 patients, in comparison to an analysis of lymph nodes and outcomes.

If the predictive and diagnostic power of these proteins is validated, they could be analyzed in primary tumor biopsies that are routinely collected at the time of diagnosis, saving some women from extensive and possibly unnecessary therapy as well as from undergoing a second surgery to collect lymph nodes for analysis, the scientists say.

"We want to be able to predict, at the earliest stages, if a tumor has spread and how dangerous it will be," said the study's lead author, Dave S. B. Hoon, Ph.D., director of Molecular Oncology at the John Wayne Cancer Institute, Saint Johns Health Center, in Santa Monica, California. "These two proteins may allow us to target aggressive tumors with more extensive treatment management to some women, while sparing others from needless therapy".........

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