 Novel Drugs Block Tumor Growth
Good ole aspirin finds use against stomach cancer
ASPIRIN LOWERS RISK OF STOMACH CANCER
HONG KONG
A study by a Hong Kong University research team found that long-term use of aspirin may reduce the risk of stomach cancer. The team reviewed data from 2,831 stomach-cancer patients and found that long-term use of aspirin or steroid-free antiinflammatory drugs could reduce the risk of stomach cancer by 22 percent.
The results were published in the Journal of the National Cancer Institute, but researcher Dr. Benjamin Wong said it was too early to forecast whether aspirin could be used to treat cancer. "The results we have at this stage is for prevention only and we do not want to cause confusion that this could also be for treatment purposes," said Wong.
He added this was merely a "first step" to prove the principle that aspirin could reduce the risk of cancer and stressed more tests needed to be done, including a clinical trial, to prove the results were accurate.
Globally, stomach cancer is the fourth most common cancer with an estimated 876,300 new victims recorded in 2000. It is also the second leading cause of cancer deaths, according to the World Health Organization.
GENETIC SWITCH FOR BREAST CANCER...
WASHINGTON
Researchers reporting at the 24th annual congress of the International Association for Breast Cancer Research in Sacramento, California say they have discovered a genetic switch in mice that can prevent or reverse the effects of breast cancer.
A team of scientists from Canada, Switzerland and the University of California at Davis demonstrated that removing a single gene known as beta-1 integrin prevented or halted breast cancer growth in laboratory mice. The gene is a principal regulator of normal breast tissue growth and survival.
"It's enormously gratifying," said Robert Cardiff, one of the authors of the study. "Our findings suggest paths forward that may help us alter the biological path of breast cancer and more successfully treat-and even potentially prevent-this cancer in humans."
...BLOOD TEST FOR DETECTING IT
OSLO
A simple blood test could in the future be used to detect breast cancer, which affects 10 percent of women in the Western world, a Norwegian group developing the method said.
"When you get a disease, it's not only the primary site of the disease that responds. There are responses in other parts of the body as well. Our method aims at detecting those responses," said Anders Loenneborg, head of the DiaGenic research company. "Cancer provokes a different activity of genes in the blood. We are trying to find a pattern of gene activity that is characteristic to breast cancer."
Loenneborg said his group had already managed to detect a "pattern" of 49 genes found in women with breast cancer where the illness had been detected by traditional methods like mammography and ultrasound.
DiaGenic is currently researching whether this pattern is specific to breast cancer or applies to other kinds of cancer or illnesses. If their results prove conclusive, the detection method could be put on the market in two years, "if we have all the optimal conditions," that is, if financing and opportunities permit, Loenneborg said.
The biggest advantage of the blood test method is that it provides the possibility of early detection. "These changes in the gene activity are the first changes that take place. So you can detect the cancer at a very early stage," Loenneborg said.
The method would make it possible to detect a tumor measuring less than five millimeters.
The blood test is also simple. "You can take a blood sample anywhere and send the sample to a centralized lab," he said. This would allow people to avoid waiting queues and eliminate the need for each hospital to install special equipment.
The method would at first be used as a complement to mammography, not as a replacement.
EXPERIMENTAL DRUGS SLOW TUMOR GROWTH IN MICE
BOSTON
Experimental drugs have shown promising results in inhibiting the growth of deadly brain tumors in animals and are expected to be equally effective in humans, US researchers said.
The drugs significantly slowed the growth of human tumors that were implanted in laboratory mice by blocking the process by which the tumor grows new blood vessels that allow it to thrive and grow.
One of the drugs-ZD6474-delayed the growth of three types of central nervous system tumors by up to three weeks, a significant achievement given the short life cycle of a mouse and the fact that the drug was only given to the animal for 10 days, the researchers said.
The same drug was found to be effective against three different types of brain tumors, "a remarkable finding given that brain tumors are very distinct in their biologic makeup," said Jeremy Rich, an assistant professor of medicine in the Brain Tumor Center at North Carolina's Duke University.
Three of the experimental drugs are in a new class of small molecule inhibitors that are designed to prevent growth factors from activating themselves inside cancer cells.
Cancer cells overproduce growth factors that cause cells to rapidly reproduce to unnaturally prolong their lives, to grow blood vessels to support their growth and to invade surrounding tissue.
In the past five years, cancer researchers have targeted their efforts on agents that can block the process by which endothelial cells form new blood vessels to bring oxygen and nutrients to tumors. More than 60 antiogenic agents, which block new cell growth, are in clinical trials in the US, and while they appear to be safe and well tolerated, positive the-rapeutic outcomes have been scarce, according to a recent article in the Journal of the American Medical Association.
As a result, researchers continue to explore new antiogenic agents in hopes of transforming cancer from an acute, lethal illness into a chronic, manageable one by slowing the growth of tumors.
The Duke University researchers also had some success using two compounds in unison: AEE788, which targets a protein that cells use to grow new blood vessels, to resist dying, and to invade other cells, and RAD001, which targets a different cancer cell protein, disrupting a cell's metabolism and preventing normal cell development. The two compounds are slated for testing in humans.
HIGHER PROSTATE-CANCER RECURRENCE RISK FOR OBESE MEN
WASHINGTON
Obese men who have prostate cancer are at a higher risk of suffering from aggressive tumors, or a recurrence of cancer, than their slimmer counterparts, according to two studies published in the Journal of Clinical Oncology.
"The primary role of obesity in prostate cancer is still unclear, but it appears to induce the development of more aggressive tumors," said lead author Christopher Amling of the Naval Medical Center's Department of Urology in San Diego.
"I would advise patients to maintain a normal body weight to limit the possibility that they would develop clinically significant, more aggressive prostate tumors," he said.
Two studies examined the relationship between obesity and reappearances of prostate cancer across a broad range of men who had had their prostate gland removed due to cancer.
Amling's team studied more than 3,000 prostate-cancer patients, 19 percent of them obese. Another study, led by Stephen Freedland of Johns Hopkins School of Medicine at Baltimore, Maryland, examined more than 1,000 people, 22 percent of them obese. According to Amling and Freedland, proteins and hormones contained in body fat might favor the growth of cancerous prostate tumors among obese men.
SINGAPORE-MADE NOSE CANCER KIT GOES GLOBAL
SINGAPORE
A drop of blood is all that doctors will need to check for nose cancer with a Singapore-made detection kit that will be sold globally. The kit will make it possible to obtain a diagnosis within a few hours by adding several chemicals to the blood and placing the mixture into a special machine, the Straits Times reported.
The test, which will cost about US$18, is just as accurate but simpler and faster than the traditional blood test, which takes several days and requires an expert technician to culture the blood cells, process them, and read the results. However, it is still not as thorough as a nasal endoscope, where a specialist inserts a flexible scope into a patient's nasal passage.
"The gold standard for diagnosis is, of course, the nasal endoscope, but this is limited to specialists who have the equipment and expertise," said ear, nose, and throat specialist Goh Yau Hong. "But the kits can provide early screening. So a patient can go to a GP (general practitioner) first and get the test. It will identify who should go for more complex tertiary care."
The test kit was based on technology developed by the Nanyang Technological University in Singapore three years ago. It has been packaged for widespread use by Inflexion, a fledgling marketing company.
Nose cancer is the fifth most common cancer in Singapore. It is the fourth most common among men in Southern China and Hong Kong, according to Pacific Bridge, a consulting firm for medical companies in Asia.
RICH COUNTRIES FACE CANCER "EPIDEMIC" FROM ASBESTOS
PARIS
Lung cancer caused by asbestos will cause 100,000 deaths in the developed world alone over the next 25 years.
The British Medical Journal (BMJ) said in an editorial in January that the disease "is increasing in frequency, and there is nothing we can do now to prevent it in workers exposed to asbestos throughout the 1950s, 1960s, and 1970s."
"Many countries are seeing the rising tide of an epidemic, and all doctors need to know how to recognize and diagnose this disease and what treatments are available," the editorial said.
The type of cancer is malignant pleural mesothelioma, in which irritation caused by inhaling asbestos fibers provokes a tumor in the lung lining. Those most at risk are men who worked in the building industry, particularly carpenters and joiners, before asbestos was outlawed. But wives and daughters who washed the overalls of asbestos workers have also developed and died from mesothelioma.
The substance became widely deployed from the 1940s as a heat insulator and fire retardant, appearing in partitions, filters, brake linings, and cement.
In Britain, deaths from mesthelioma are running at more than 1,800 a year, accounting for about one in 200 deaths in men and one in 1,500 in women, the BMJ said.
The epidemic will peak in 2015-2020, both in Britain and Europe, although the peak has probably already passed in the US, which acted faster to curb asbestos use. The authors, all leading authorities in cancer treatment and epidemiology, are led by Tom Treasure, a professor at Guy's Hospital, London.
|
