20 Possible Causes of Cancer
For the most part, none of us know why we got cancer. Women who carry one of the gene mutations, BRCA1 or BRCA2, can blame it on that. People who have been smokers or exposed to asbestos and later are diagnoses with lung cancer can identify possible reasons. There are a few other more rare known carcinogens, but we are mostly left to blame it on rotten bad luck. Many of us suspect that there is something (actually, many somethings) about our environment that may be the culprit. It is virtually impossible to tease out specific environmental factors. How do you design a study that looks at exposure to, say, dry cleaning fluids while insuring that every other possible thing about the study group is identical. (that is, did everyone always eat the same foods, use the same cleaning products, breath the same air, etc.) My own hunch is that an individual's cancer is caused by a lethal combination of genetic vulnerability and exposure to something toxic--that is, both our bodies and the world are responsible.
For myself, I suspect that my father's work as the director of the Army's first nuclear power plant (long before anyone wore badges to measure radiation exposure) may be to blame. Who knows what was on his clothes when he came home and hugged me every night? I do know that he, a non-smoker, died of a virulent form of lung cancer that, two years later, killed the man who succeeded him in the same job.
At any rate, this is an article from The New York Times that reports on a new American Cancer Society list of twenty possible carcinogens that should be further studied. I would welcome your comments and thoughts.
July 15, 2010
U.S. Groups Target 20 Possible Causes Of Cancer
Filed at 2:55 p.m. ET
WASHINGTON (Reuters) - The American Cancer Society and three federal agencies named 19 chemicals
and shift work on Thursday as potential causes of cancer that deserve more investigation. The group published a report with the backing of international experts who said the 20 potential causes they identified had fairly good evidence that they may be a danger and deserved more follow-up.
Most are familiar names, such as chloroform, formaldehyde and polychlorinated biphenyls or PCBs, but the list includes indium phosphide, a relatively new compound used in making flat-screen televisions.
All have been classified as possible carcinogens by the International Agency for Research on Cancer or IARC, the United Nations cancer agency.
"These particular ones were picked for two reasons. One is there is more of a hint in most cases that they might be involved with cancer," Elizabeth Ward of the American Cancer Society, who helped lead the work, said in a telephone interview. But at the same time, she said, the studies that could make a definitive link are missing. The second reason is that some of the potential agents or causes are very common. "We are focusing on things like formaldehyde, where there really has been widespread exposure in many industries," Ward said.
"Or in some cases the exposure is not widespread but is something that is increasing and there is insufficient data."The National Institute for Occupational Safety and Health or NIOSH, National Institute of Environmental Health Sciences and the National Cancer Institute also helped sponsor the report, which names the
-Lead and lead compounds
-Cobalt with tungsten carbide
-Refractory ceramic fibers
-Styrene-7,8-oxide and styrene
-Dichloromethane, methylene chloride (DCM)
-Tetrachloroethylene (perc, tetra, PCE)
-Polychlorinated biphenyls (PCBs)
-Di(2-ethylhexyl) phthalate (DEHP)
The study is published in the journal Environmental Health Perspectives and at http://monographs.iarc.fr/ENG/Publications/techrep42/index.php.
Ward said indium caught the group's attention because it is becoming increasingly common. Used to make microelectronics, animal data suggested it might cause lung damage and genetic changes when breathed in, she said.
"It is a particularly important component of the flat displays of TVs that have been so popular," she said. Workers in assembly plants and those recycling discarded televisions might be most at risk, she said. "Some of this kind of work done is in developing countries," she noted. "They are broken apart and valuable
components extracted. It is an example of a newly emerging hazard."
Cancer is the No. 2 killer of Americans and people in most industrialized countries, after heart disease.
In May the President's Cancer Panel said Americans are being "bombarded" with cancer-causing chemicals and radiation but many experts said it overplayed some causes for which there is very little evidence of a cancer-causing effect, such as cell phones.