Cancer spreading, but experts confident of taming it
ORLANDO, Florida
Cancer continues to spread quickly across the world, but medical researchers feel confident they can tame it. They say they have begun to target its inner workings with new and very promising molecular weapons.
"This is truly the golden age for experimental cancer therapy and we have an unprecedented opportunity to make real progress," University of California's Dr. Charles Sawyers said, echoing predominant feeling among some 25,000 cancer specialists, researchers, and representatives of medical and biotechnological companies that met in Florida in May for the 41st annual conference of the American Society of Clinical Oncology (ASCO).
His optimistic outlook was backed up by clinical trial results of new-generation, anticancer molecules that attack several of cancer's cellular mechanisms. They selectively block the growth of blood vessels that nourish tumors and the signals that order cancer cells to multiply.
Pfizer presented promising results of Sutent in reducing advanced breast, lung, and kidney cancer in patients who are unresponsive to existing treatments. Eli Lilly, AstraZeneca, and Amgen also have multitargeting anticancer treatments in the works. GlaxoSmithKline also announced encouraging preliminary results in clinical trials with Lapatinib to reduce breast cancer by zeroing in on the HER-2 protein.
However, experts like Prof. Bernard Stewart, coauthor of the World Health Organization's 2003 report on cancer, cautioned that "the new drugs will not necessarily eradicate tumors but, when used in combination with other agents, they may turn cases of rapidly fatal cancer into manageable, chronic illness."
Cancer specialists also stress that the new therapies' success will depend on improved diagnosis that can detect cancer cells when they first form in the body. In the coming years, experts predicted, medical research will perfect fluorescent probes capable of seeing small, precancerous cell formations. Current imaging techniques (mammograms, magnetic resonance, and tomodensitometry), as well as the prostate-specific antigen for prostate cancer, have proved how vital early detection is to reduce the death rate from cancer.
From 1993 to 2001, the yearly cancer death rate fell by 1.1 percent, while cancer survivors--no remission in at least five years--went from three million in 1971 to 9.8 million in 2001. Prevention continues to be the best way of reducing cancer, which is expected to rise from 10 million cases in 2000 to 15 million in 2020. In the 20th century, smoking-related cancer killed 100 million people.
H-bomb tests still cause cancer in Marshall Islands
MAJURO
A study has found that the number of cancers caused by hydrogen-bomb testing in the Marshall Islands is set to double, more than half a century after the tests were conducted in the tiny Pacific nation.
The study by the United States National Cancer Institute (NCI) estimated 530 cancers had already been caused by the tests, particularly the explosion of a 15-megaton hydrogen bomb codenamed Bravo on March 1, 1954. It said another 500 cancers were likely to develop among Marshall Islanders who were exposed to radiation more than 50 years ago.
"We estimate that the nuclear-testing program in the Marshall Islands will cause about 500 additional cancer cases among Marshallese exposed during the years 1946 to 1958, about a nine-percent increase over the number of cancers expected in the absence of exposure to regional fallout," the NCI study said.
The study said that because of the young age of the population when exposed in the 1950s, more than 55 percent of cancers have yet to develop or be diagnosed. The NCI completed the study in September last year but released the results only in April after officials from the Marshall Islands noticed a reference to it in a US Congressional report and requested a copy.
At the time of the Bravo test at Bikini Atoll, US officials played down the health implications for islanders. Bikini Islanders were not evacuated despite their land's being engulfed in snow-like radioactive fallout for two to three days after the Bravo bomb, which was equivalent to 1,000 Hiroshima bombs.
Although many islanders developed severe radiation burns and had their hair fall out as their land was engulfed in fallout, US Atomic Energy Commission authorities issued a statement following the test saying "there were no burns" and the islanders were in good health.
US officials later allowed islanders to return home to live in radioactive environments without performing any cleanup work on the islands. The US paid US$270 million in a compensation package in the mid-1980s, part of which went to the Majuro-based Nuclear Claims Tribunal. But the tribunal says only a limited amount was made available for payouts and has described the original settlement as "manifestly inadequate."
Danish study finds no increased risk from cell phones...
COPENHAGEN
Mobile phones do not increase the risk of cancerous tumors of the brain, according to a new study by the Danish cancer society.
The Kraeftens Bekaempelse's researchers interviewed 427 Danes with brain tumors and 822 others without tumors about their usage of mobile phones.
"This study shows very clearly that using portable phones does not increase the risks of developing brain cancer. And our findings are similar to those of other major studies, including a recent one published in Sweden," said Prof. Christoffer Johansen, who headed the research.
Another Nordic study, in which the Danish cancer society participated, also came to the same conclusions. "It is too soon to say if over the long term the frequencies of mobile phones, introduced in Denmark in the early 1980s ... will have a negative effect on the brain," Johansen said. "But since we have not seen for 20 years the slightest tendency toward a risk of cerebral tumors, it is difficult to imagine that using portable phones would be an essential factor in the risk of brain cancer."
The Danish cancer society, however, recommends that rather than holding the mobile phone to the ear, everyone, especially children and teenagers, should make use of the ear pieces in the hands-free kits that usually come with mobile phones.
...but Swedes disagree, find link with brain cancer
PARIS
A Swedish study is poised to sharpen debate about the safety of mobile phones, for it contends that users of digital phones in rural areas may be at greater risk of brain cancer.
Incidence of brain tumors in rural zones of Sweden was found to be far higher among users of the Global System for Mobile Communication (GSM) network than among rural nonusers and GSM users in urban areas, the study says. Its authors say the link is troubling, although they acknowledge that the amount of data is low and wider research is needed to amplify the findings.
As for the possible cause, the study suggests that mobile handsets in rural areas deliver a higher dose of electromagnetic radiation because they have to transmit a stronger signal to distant transmission masts. Transmission masts in urban areas are closer together, which means the phone's signal and thus radiation level are correspondingly weaker, it says.
The study, headed by Lennart Hardell, a professor of oncology at University Hospital in Orebro, appears in Occupational and Environmental Medicine.
The team trawled through a databank of the population of central Sweden, a swath of the country that includes its major cities as well as the remote countryside. Around 1,400 adults ages between 20 and 80 were diagnosed with a malignant or benign brain tumor between January 1997 and June 2000. Their profiles were compared with a similar number of healthy adults, matched for age and sex and living in the same geographical area.
The investigators sent out a questionnaire to all to ask about daily use of mobile and cordless phones. The study found that how long users spent on the phone had no impact on the probability of being diagnosed with a brain tumor. But where they lived was a big factor, and especially for digital mobile phones.
Residents of rural areas who had been using a digital mobile for more than three years were more than three times likelier to develop a tumor than urban counterparts. Among those who had been using the phone for more than five years, the risk quadrupled. No such effect was seen for old-fashioned analog or cordless phones.
First blood test for asbestos-related cancer
SYDNEY
Australian researchers have developed the world's first blood test that could help early detection of the deadly mesothelioma, an asbestos-related form of lung cancer.
Research team leader Bruce Robinson of the University of Western Australia said there is no cure for the disease, but early detection and treatment could lead to a breakthrough. "Sometimes it can take a very long time to diagnose this cancer but if you've got a blood test, it can help you diagnose it straight away, then the possibility exists that you could get in and treat earlier," said Robinson.
"The test is a breakthrough because it's a simple blood test," Dr. Nick Pavlakis, a leading mesothelioma researcher in Sydney, said. "It could therefore be applied to patients who are at risk, those who have symptoms of the disease or a history of exposure [to asbestos]."
New therapy reduces painful side effects
SINGAPORE
Singaporean researchers have discovered a new way to combat cancer that delivers drugs with microscopic precision and minimizes painful side effects. Scientists from the Institute of Bioengineering and Nanotechnology have created "smart" polymer nanoparticles that deliver anticancer drugs directly to diseased tissues.
The new cancer treatment, which has been successfully tested on small animals, would significantly reduce side effects, such as fatigue and hair loss, that cancer patients who undergo traditional chemotherapy commonly suffer.
"Previous attempts by other scientists involved the use of core-shell nanoparticles that were only sensitive to temperature," said lead scientist Yang Yi-Yan.
Drug delivery may be controlled by superficially heating or cooling the environment of the nanoparticles. Yang said the novelty of the invention was "the ability of nanoparticles to target drugs to deep tissues or cell compartments without changes in temperature."
Biological signals tagged onto the nanoparticles, which are less than 200 nanometers in size, enable them to recognize tumor sites in the body and subsequently release the anticancer drugs into the cancer cells. A nanometer is a billionth of a meter, or roughly one-hundred-thousandth the diameter of a human hair.
The technology will undergo clinical trials within the next five years. It is expected to make inroads into the cancer-drug-delivery market, which is forecast to grow to US$15.4 billion by 2007.
Exercise boosts chances of survival
WASHINGTON
Women stricken with breast cancer can boost their chances of survival by 50 percent with some exercise, according to a study in the Journal of the Medical Association.
"This is good news for women with breast cancer," said Dr. Michelle Holmes, a Harvard Medical School assistant professor who led the study. "Women with breast cancer have little to lose and much to gain from exercise."
The study was conducted among some 3,000 nurses diagnosed with different stages of breast cancer between 1984 and 1998 and who were monitored until June 2002. It showed that walking at an average pace for three to five hours a week reduced the risk of death by 50 percent compared with more sedentary women.
"The most logical explanation is that physical activity lowers hormone levels, and the lower hormone levels reduce the chances of a recurrence," Homes said. "Women don't have to run marathons for the maximum benefit," she added.
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