We know how to stop many cancers before they begin, scientists say. But more work is to be done.
"Nearly half of cancers can be prevented," says Christopher Wild at the opening session of a global scientific meeting on cancerous environmental causes held in June. Wild was formerly director of the International Agency Organization of the World Health Organization for Cancer Research.
"The biology of cancer and treatment is where the majority of money goes," he said, but the caution gave more attention. "I'm not saying we should not work to improve the treatment, but we do not balance it properly."
Perhaps no question about cancer is more conflict than its causes. People wonder, and debate by scientists, if most malignancies come from random mutations of DNA and other occasions at times or from exposure to carcinogens, or from behaviors that can be avoided .
At the conference in Charlotte, N.C., scientists exerted a re-examination of the role of environmental explosions by applying modern molecular methods of toxicology. They call for a more aggressive collection of human pathology examples and environmental examples, including water and air, so that cellular responses to chemicals can be identified.
Hope is by identifying specific traces of exposures to specimens of human cancers, scientists can identify the causes of environmental illness that can be avoided. "More than 80,000 chemicals are used in the United States, but only a few have been tested for carcinogenic activity," says Margaret Kripke, an immunologist and emeritus professor at MD Anderson Cancer Center, during a meeting.
] "This is a very neglected area of cancer research for the last few decades," said Kripke, the driving force behind the conference, which was put on by the American Association for Cancer Research. "Environmental toxicology was very popular in the 1950s and 1960s," he said, but genetics began to go beyond the study of the causes of cancerous environment. "Toxicology has fallen by the road."
As cigarette-related cases have fallen, malignancies that are not related to smoking are rising, Kripke said. Recent evidence suggests a throbbing rate of lung cancer among incumbents. That tendency implies other environmental factors.
Worldwide, the general range of cancer is rising. This year, 18 million people will discover some types of cancer and more than 9 million will die from it.
Infections – many preventable, such as human papillomavirus -make up for 15% of new cases.
Another rising cause is obesity, including urbanization. People generally get less physical activity and eat different cities, and pollution is much heavier. "As people move to cities, they will continue to be cancer rates," Wild said.
One of the biggest barriers to prevent cancer is that many people do not think it's possible. The development "requires long-term vision and commitment," Wild said. "Funding is limited, and there is little investment in the private sector."
A change in the way the benefits of cancer prevention are helpful can help. "When IARC was in, something I struck was the power of economic arguments in health arguments to prevent cancer," Wild said.
Costs of cancer treatment can be prevented. But losing productivity from premature deaths in Brazil, Russia, India, China and South Africa alone is $ 46.3 billion a year, he said. "Developing countries are not ready to deal with the increase of cancer burden."
The exact proportion of cancer that comes from exposure to the environment and work on carcinogens is uncertain. In 2009, a report by the President's Panel of Panel was called before about roughly 6% "woefully outdated" and low. A 2015 paper by more than one hundred concerned scientists cited "credible" estimates of 7% to 19%.
Scientist at the Charlotte meeting identified the complexity of the causes of cancer and the need for toxicologists to update the procedures to reflect the complexity, as through the study of interactions environmental and genetic hazards, and by analyzing cells after an integration of exposures. "Most toxic exposures can not happen one at a time," says Rick Woychik, deputy director of the National Institute of Environmental Health Sciences.
Until recently, many toxicological experiments have been made on rodents, as it is unreasonable to deliberately check the possible carcinogens in humans. But these animal experiments are zealous and slow in action, he said.
New alternatives are now being tested. "We learned from pharma with robots and high-throughput technology you can interrogate many biology quickly and at lower costs," he said.
Epidemiological research on human exposures has eliminated the difficulty in proving cause-effect – that a particular substance really causes cancer – and with the lack of survey data from questionnaires.
At conferences, scientists offer glimpses of new technologies that help fill in the lack of information.
MIT's Bogdan Fedeles said how DNA serves as a lifetime of "recording device." He and others use duplex sequencing to examine human samples for genetic "fingerprint exposure."
Allan Balmain, a geneticist at the University of California, San Francisco, spoke about mutational signatures on malignancies. In liver cancer, for example, these signs may offer factors that cause stiffness-such as smoking, alcohol or aflatoxin, a mold product that grows in some foods.
Many chemicals that cause or stimulate cancer growth are made within our bodies. "Not all about the environment," Balmain said.
Others exhibited an imaginary shift in how scientists are referring to carcinogens. Key features may include the capacity of something to stimulate the growth of malignant cells, or encourage inflammation-which does not necessarily cause harm to DNA, which has long been seen as necessary.
"The answer to & # 39; What a cancer arthritis? & # 39; is changing" says Ruthann Rudel, a toxicologist at the Silent Spring Institute that publishes breast cancer carcinogens. Detailed new techniques to screen breast cancer cells for changes in response to specific chemical exposures.
High public health fields. Professor Polly Hoppin, of the University of Massachusetts, Lowell, discussed industrial contamination of drinking water at Camp Lejune, NC, wind pollution in St. Petersburg. John the Baptist Parish, La., And potential exposures to carcinogens from fracking and planning the production of plastic in Pennsylvania.
Hoppin describes the U.S. experience to stop smoking. Scientists know that smoking causes cancer in the 1950s, he said. Implementing knowledge that requires policy and incentives – such as high cigarette taxes and smoking restrictions in the public – and hold decades.
"Science is not enough," Hoppin said. "How many lives can be saved if we want to act earlier?"
Elaine Schattner is a New York physician who writes a book on cancer attitudes to be published by the Columbia University Press.