December 13, 2006, 4:40 AM CT

Older Men With Early Prostate Cancer

Recent findings from an observational study by researchers at the University of Pennsylvania School of Medicine suggest that men between 65 and 80 years of age who received treatment for early stage, localized prostate cancer lived significantly longer than men who did not receive treatment. The study would be published in the December 13th issue of the Journal of the American Medical Association.

Thanks to better cancer prevention education and the resulting wide-spread increase in using prostate-specific antigen (PSA) screenings, more men are being diagnosed with early-stage and low-or intermediate-grade prostate cancer. Studies have shown that the slow-developing nature of prostate cancer during its earliest stages makes treatment options, such as a radical prostatectomy (surgical removal of the prostate) and radiation therapy, controversial with unpredictable outcomes. Often, recently diagnosed men of this group were advised to just "watch and wait" to see how their situation progressed.

"For this study we looked back over the existing data of a large population of prostate cancer patients, aged 65 to 80, with small tumors that were at a low or intermediate risk of spreading," said senior author Katrina Armstrong, MD, MSCE, who worked on the study with colleagues from Penn's Abramson Cancer Center, Center for Clinical Epidemiology and Biostatistics, Leonard Davis Institute of Health and Economics, and Division of Internal Medicine, and Fox Chase Cancer Center. "After accounting for all their differences, we discovered that the men - who within six months of diagnosis underwent surgery or radiation therapy - were 31 percent less likely to die than those who did not undergo treatment during that time".........

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December 12, 2006, 5:11 AM CT

Breast Cancer Screening Trials For Under 50s

A ten year trial in which women between the ages of 40 and 50 were invited for annual breast screening did not show a significant reduction in breast cancer mortality.

The report by researchers at The Institute of Cancer Research is published recently in the Lancet. The trial was funded by Cancer Research UK, the Medical Research Council and the Department of Health. It involved around 160,000 women, of whom a third received annual screening invitations and two-thirds usual medical care.

The trial was the first of its kind to invite only women of 40 or 41 at the start of the trial to ensure all results were based solely on screening before age 50. Currently, when women reach the age of 50 they are invited for screening every three years by the NHS Breast Screening Programme.

The researchers estimated that screening from age 40 could save four lives for every 10,000 women screened. But it was reported that the benefit of screening women in their 40s needs to be balanced against possible negative considerations such as increased radiation exposure - which can contribute to breast cancer risk, and recalling women who do not have cancer for further tests - leading to their anxiety and resulting in higher financial costs for the screening programme.

Of those women invited for the first screening 68 per cent attended. But the figure fell in later rounds, partly due to women moving away from the study areas. This led scientists to conclude that the potential benefits of screening the under 50s could be greater than that observed.........

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December 12, 2006, 5:05 AM CT

Almost Half Of Lung Cancer Patients Go Back To Cigarettes

New research has shown that the development of lung cancer and surgery to remove it is still not enough to put many smokers off picking up cigarettes again.

A Washington University School of Medicine study of 154 smokers who had surgery to remove early stage lung cancer found almost half picked up a cigarette again within 12 months of their operations.

The researchers found that 43 per cent of patients smoked at some point after surgery and 37 per cent were smoking 12 months after their operation.

Furthermore, 60 per cent of those who took up smoking again did so within two months of surgery.

Highlighting the dangerous addictiveness of cigarettes, Mark Walker, a clinical psychologist and assistant professor of medicine at Washington University, said: "These patients are all addicted, so you cannot assume they will easily change their behaviour simply because they have dodged this particular bullet.

"Their choices are driven by insidious cravings for nicotine".

Contrary to predictions, researchers found no link between the quantity of smoking and the ability to quit, and also discovered that higher education was associated with a greater likelihood of smoking after surgery.

"It wasn't the number of cigarettes smoked daily that determined who couldn't quit, but how long they continued to smoke before surgery," Professor Walker explained.........

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December 8, 2006, 5:08 AM CT

Viagra Against Cancer?

Sildenafil and other "impotence drugs" that boost the production of a gassy chemical messenger to dilate blood vessels and produce an erection now also show promise in unmasking cancer cells so that the immune system can recognize and attack them, say researchers at the Johns Hopkins Kimmel Cancer Center.

Tests at Hopkins on mice with implanted colon and breast tumors showed that tumor size decreased two- and threefold in sildenafil-treated animals, in comparison to mice that did not get the drug. In mice engineered to lack an immune system, tumors were unaffected, proof of principle, the researchers say, that the drug is abetting the immune system's own cellular response to cancer.

In a report reported in the Nov. 27 issue of the Journal of Experimental Medicine, the Hopkins team says boosted levels of the chemical messenger nitric oxide appear to dampen the effects of a specialized cell that diverts the immune system away from tumors, allowing swarms of cancer-attacking T-cells to migrate to tumor sites in the rodents.

Lab-grown cancer cells treated with sildenafil showed similar results, as did tissue samples taken from 14 head and neck cancer and multiple myeloma patients.

Sildenafil, marketed under the trade name Viagra, is one of a class of drugs used to treat erectile dysfunction in millions of men, and in recent years, its ability to stimulate the production of NO has been investigated by experts in diseases associated with the activity of blood vessels and blood components.........

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December 7, 2006, 9:54 PM CT

Blood Pressure Drugs And Pancreatic Cancer

Common blood pressure medications might help block the spread of pancreatic cancer, researchers at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia have found. The scientists showed in laboratory studies that two types of pressure-lowering drugs - ACE inhibitors and AT1R blockers - may help reduce the development of tumor-feeding blood vessels, a process called angiogenesis. Such drugs, they say, may become part of a novel strategy to control the growth and spread of cancer.

According to Hwyda Arafat, M.D., Ph.D., assistant professor of surgery at Jefferson Medical College, previous studies have linked a lower cancer incidence with the inhibition of the pancreas hormone angiotensin II (Ang II) by either ACE (Angiotensin I converting enzyme) inhibitors or AT1R (Ang II type 1 receptor) blockers. Ang II increases the production of VEGF, a vascular factor that promotes blood vessel growth in a number of cancers. High VEGF levels have been correlated with poor cancer prognosis and early recurrence. ACE is the enzyme that converts Ang I to Ang II.

Dr. Arafat and her co-workers examined the protein of both invasive pancreatic cancer and normal pancreatic tissue, analyzing the expression of ACE and AT1R in relation to VEGF. They also looked at the effects of blood pressure drugs captopril, an ACE inhibitor, and losartan, an AT1R blocker, on VEGF production in cancer cell lines.........

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December 3, 2006, 9:10 PM CT

Math Model To Predicts Cancer

Vito Quaranta clicks on a small black dot on his computer screen. The dot which represents about a thousand cancer cells begins to "grow," morphing into a mass with finger-like projections that looks like an invasive tumor.

The Vanderbilt professor of cancer biology envisions a future when computer simulations like this will be used to predict a tumor's clinical progression and formulate individualized therapy plans. For the last two years, he has headed a major effort to develop the kind of mathematical model for cancer invasion powerful enough for this purpose. The result was published as an entirely theoretical paper in the journal Cell and, if he is right, it represents a "sea change" in how biology is done.

The new approach is not so different from forecasting the weather.

"Today we can know pretty well that for the next few days we're going to expect good weather or that there's a storm on the way," Quaranta said. "That's the kind of predictive power we want to generate with our model for cancer invasion".

Quaranta and his colleagues at Vanderbilt University and the University of Dundee in Scotland developed a computational model for cancer invasion and described the model in the Dec. 1 issue of Cell. The model a series of mathematical equations that drive computer simulations of tumor growth suggests that the microenvironment around tumor cells determines the tumor's ultimate cellular makeup and invasive potential.........

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November 28, 2006, 4:59 AM CT

Big Bias In Who Gets Screened For Breast Cancer

Certain women may miss out on routine tests that screen for early signs of breast cancer.

Elderly women, women with publicly funded health insurance and women who don't go to an obstetrician and gynecologist for routine exams are all less likely than others to get a clinical breast exam and a recommendation for a mammogram.

"A physician's recommendation is why many women undergo screening in the first place," said Rajesh Balkrishnan, the Merrell Dow professor of pharmacy at Ohio State University. "Foregoing these exams can increase a woman's risk of developing an advanced stage of breast cancer. There are several reasons why a doctor may not give a patient a clinical breast exam or recommend a mammogram".

Balkrishnan led a study that uncovered some of these possible reasons. The findings currently appear online at the website of the journal Breast Cancer Research and Treatment.

The researchers gathered data from the National Ambulatory Medical Care Survey (NAMCS), a database run by the Centers for Disease Control and Prevention. The NAMCS contains information on a nationally representative sample of practicing physicians and patient visits throughout the United States. The researchers restricted their data set to doctor office visits by women 40 and older from 1996 through 2004.........

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November 27, 2006, 5:04 AM CT

Chemotherapy Temporarily Affects The Brain

Scientists have linked chemotherapy with short-term structural changes in cognitive areas of the brain, as per a new study. Reported in the January 1, 2007 issue of CANCER (http://www.interscience.wiley.com/cancer-newsroom), a peer-evaluated journal of the American Cancer Society, the study reveals that within 12 months of receiving adjuvant chemotherapy, significant regions of the brain linked to memory, analysis and other cognitive functions were significantly smaller in patients with breast cancer who received chemotherapy than those who did not. Within four years after therapy, however, there were no differences in these same regions of the brain.

While the development of chemotherapy has had substantial and beneficial impact on cancer survival rates, it is also associated with significant short- and long-term adverse effects. Gastrointestinal complaints, immunosuppression, and painful mucositis, for example, are the immediate risks of the therapy.

Patients receiving chemotherapy have also long complained of problems with memory, problem-solving and other cognitive abilities. Eventhough chemotherapy was thought not to affect brain cells due to the blood-brain barrier, recent clinical studies have confirmed declines in cognitive functions in patients receiving chemotherapy. Animal studies have shown physical changes in the brain and in neurons caused by chemotherapy drugs. In human studies, however, the little data that is available is only available through imaging and is not consistent in the long-term. In addition, lack of controls in studies makes it difficult discern cancer- versus drug-effects.........

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November 22, 2006, 4:45 AM CT

Side-effect-free chemotherapy

Treating cancer with chemotherapy can be as destructive to healthy cells as it is to tumour cells, causing notorious, debilitating side effects. US scientists have now developed an enzyme with the potential to eliminate the extreme fatigue, sickness and hair loss that result from this cell damage and strike fear into the hearts of cancer patients.

The researchers, led by Zaver Bhujwalla from Johns Hopkins University in Baltimore, developed a traceable enzyme to activate cancer prodrugs. The enzyme can be tracked on its journey within the body, to ensure that it has been cleared out of healthy tissue before the prodrug is introduced.

'Blood vessels of tumour cells are much leakier than normal, healthy vasculature so the enzyme leaks into the tumour but is cleared out of healthy tissue by the bloodstream,' Bhujwalla explained.

The enzyme, cytosine deaminase was chemically tagged with two tracers, gadolinium, which is a contrast agent that can be visualised using magnetic resonance imaging (MRI); and rhodamine, which is an optically visible tracer. Using rhodamine allowed the researchers to view sections of tissue microscopically and verify that their MRI images were accurate.

'This is the first time that a prodrug enzyme has been made visible with MRI,' Bhujwalla told Chemistry World. 'It's crucial because this type of imaging can be used in a clinical setting.'.........

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November 16, 2006, 9:40 PM CT

Tooth Whiteners Do Not Cause Cancer

Common tooth whitening products, which have been used by millions of people, are found to be safe and do not increase the risk of oral cancer when used as directed. This exhaustive review of the literature, including numerous unpublished clinical studies involving over 4,000 human subjects, appeared in an article by Dr. Ian Monroe entitled, " Use of Hydrogen Peroxide-Based Tooth Whitening Products and it Relationship to Oral Cancer," published in Journal of Esthetic and Restorative Dentistry.

Clinical and laboratory data on tooth whitening products show no evidence for the development of oral cancer or of other effects that could be associated with increased oral cancer risk. Exposures to hydrogen peroxide, generally the effective ingredient in tooth whiteners, are too low and of too short of a duration (30-60 minutes) to cause any oral tissue changes that could enhance risks for oral cancer development. Concentrations of hydrogen peroxide rapidly decline to near undetectable levels usually within 15 to 60 minutes.

Given the likely use of tooth whitening products by smokers, the review also sought to examine any possibility of increased oral cancer development due to combined exposure (i.e., hydrogen peroxide and carcinogenic agents that are present in cigarette smoke). A possible combined-effect, as seen in the increased likelihood of lung cancer development in smokers also exposed to asbestos, was found to be groundless with regards to bleaching and smoking and further illustrates the relative safety of tooth whitening products.........

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