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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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Venezuelan officials announced this week that they would investigate whether enemies could have deliberately infected late President Hugo Chávez with cancer. Chávez died on March 5, apparently of a heart attack, after battling cancer for two years.
When the former Venezuelan president was diagnosed with an undisclosed form of cancer in 2011, he speculated that his enemies could have given him the disease. He also implied that U.S. agents could have developed a technology to induce cancer, according to a CNN news story at the time. The U.S. State Department called the accusation “absurd.”
The theory that someone could be infected with cancer is not biologically impossible, but it is unlikely. A healthy immune system will combat any foreign cells, including cancerous ones. Only three types of contagious cancers have been identified, and all occur in non-primates.
Scientific American spoke with Katherine Belov, professor of comparative genomics at the University of Sydney who studies a contagious cancer called Tasmanian devil facial tumor disease. She explains why contagious cancers are rare and whether cancer could infect another person.
[An edited transcript of the interview follows.]
What are contagious cancers?
In humans, we know that you can catch viruses, like the human papillomavirus, which make you more likely to get cancer. [HPV can cause cervical cancer in women, and genital warts and anal cancer in men.] In humans, environmental causes play an important role, too—cigarette smoke and radiation exposure can cause cancer. However, we don't have any clear examples of [naturally occurring] transmissible cancers in humans.
There is a transmissible cancer in dogs. It’s a sexually transmitted disease called canine transmissible venereal tumor, or CTVT. And there is also the Tasmanian devil facial tumor disease, which I work on. The devil’s cancer causes large ulcerations in their mouth and around their jaw. When they fight—and they fight a lot—they are biting other animals, and the cancerous cells are implanting in other animals’ wounds.
In both the Tasmanian devils and in the case of CTVT, the tumor evolved in really inbred populations of animals. There was a lack of diversity and so the cancer is genetically very similar to the animals it passes to.
Why does lack of diversity help the cancer jump from animal to animal?
The cancer is transmitted to animals that are genetically similar to one another and also to the tumor. The immune system doesn't "see" it and doesn't mount an immune response. The cancer can then grow until it kills the animal.
Over time the devil’s facial tumor disease would have encountered animals that were genetically dissimilar to it. But the cancer found a way to down-regulate [or produce fewer] cell-surface molecules, which are sort of red flags to the immune system in genetically different animals. These flags are part of the major histocompatibility complex [a set of molecules attached to cells that regulate interactions with immune cells]—they are MHC molecules. Without those special immune molecules the cancer is able to fly under the radar of the immune system and pass from animal to animal.
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Add CommentUm... look: Hugo Chavez has been good friends with Fidel Castro for a while. Both the author and the interviewee should examine the CIA experiments that were plotting to deliver cancer to Castro (I believe through a vaccine). The CIA tested these 'vaccines' on the mentally ill in the 60's and 70's. Really bad stuff. It did happen though, and Chavez had a right to be concerned. I doubt that Chavez's cancer was caused by the US though; I don't think there was enough incentive to perform an assassination in that way like there was with Castro. Castro desired to attack the US with nuclear weapons during the Cuban Missile Crisis.
Reply | Report Abuse | Link to thisCancer contagious?! If it were, don't you think that it would have been obvious by now?!
Reply | Report Abuse | Link to thisCancer is trasmissible in dogs, among the Tasmanian devils and those who are genetically similar. Isn`t there some similarity between all these mentioned characters?
Reply | Report Abuse | Link to thisYes, the CIA once showed a dart gun to a congressional committee that could inject cancer or a toxin into a person, and be unnoticeable, and probably untraceable. Chavez's cancer is a rare type almost always found in children, and only occasionally in teenagers. I would say though it wouldn't be the US gov't that ordered the assassination, more likely, Big Oil or Big Banking that can't stand all those resources being under public control. Remember Big Oil caused the entire Iran nightmare by having the CIA overthrow the elected leader of Iran because he was nationalizing Iran's Oil Industry. And any fool knows the Iraq War was just a proxy war for Big Oil to gain access to Iraq's huge, dirt cheap to produce Oil resources, and added benefit (to them) of tripling the price of Oil.
Reply | Report Abuse | Link to thisMore likely Chávez's enemies infected him with paranoia.
Reply | Report Abuse | Link to thisI don't see any mention of any evidence or indication that the cancer was somehow intentionally given to Chávez - so why are we continuing this absurd speculation? Knowing that your dying is always extremely difficult...
Of course, he could have been abducted by aliens and used in DNA experiments...
The cancer death of Jack Ruby was deliberately induced by an extended chest X-ray....so they say
Reply | Report Abuse | Link to thisMore likely why are you making absurd speculation about something you have zero knowledge, but have decided that you know everything. The Venezuelan gov't claims to have evidence and the type of cancer certainly is evidence, time will tell if they release what they have, as they promise. Until then anyone who claims it is absurd speculation could well be about as bright as the average alien abductee.
Reply | Report Abuse | Link to thisI do know that those suffering from the severe side effects of cancer treatments and facing impending death are highly susceptible to mental disorders.
Reply | Report Abuse | Link to thisIf you have issues with my comments, why not address them without personal insults? Obviously my remarks were intended to be facetious, unless you are naive enough to think I was seriously suggesting that aliens are behind Chávez's cancer.
Why hasn't the type of cancer been disclosed? How would keeping that secret help to determine whether it was intentionally given to Chávez, how it was done or who did it? I know from personal experience that many people Chávez's age develop various types of cancers for many reasons without any help from other individuals.
I also understand that power corrupts, and can aggravate paranoiac tendencies without any help from cancer treatments or the very real threat of terminal cancer. You may not know anything about any of this, but I assure you that I do...
For now let's just enjoy the fact that Chavez is gone.
Reply | Report Abuse | Link to thisI regard someone calling a serious discussion of a VERY IMPORTANT issue like Presidential Assassinations - whether done covertly OR overtly - as some nutty paranoia is most definitely a personal insult. Are you trying to tell me the assassination of the Kennedy's was "paranoia", oh you can't because is it was done overtly, otherwise YOU WOULD call it paranoia.
Reply | Report Abuse | Link to thisThe ONLY rational conclusion is you believe assassins ARE ALWAYS to dumb to use covert means - yep with modern biotech what it is now, and $trillions in Oil Wealth at stake, you are emphatically stating that anyone who suggests a suspicious death was due to covert means is automatically some paranoid, alien abductee type.
Boy I would hate to see you on a jury of peers.
And it could be they are keeping the details of their evidence secret, as the police typically do, until they can build a solid case, often if evidence is leaked prematurely the bad guys have a chance to cover their tracks or plant counter-evidence. What has been rumored, as I said, is that the cancer was a type almost always found in children.
I certainly did not insult you when I implied that the possible paranoia of a dying man might be responsible for his perception that someone had intentionally given him cancer.
Reply | Report Abuse | Link to thisYou certainly were overtly attempting to insult me when you commented to me:
"More likely why are you making absurd speculation about something you have zero knowledge, but have decided that you know everything."
BTW, what does "More likely why are you..." mean - in English? I certainly don't know everything, but I am entitled to express my opinions without being insulted by blubbering morons.
One obvious speculation which seems to have been excluded by the largely left-wing media of our days is that he was killed by the Cuban health system.
Reply | Report Abuse | Link to thisWe don't know what sort of cancer he had, apparently, but some above say it was a childhood kind. Treatment of some childhood cancers is the one area where there has been some success in western medicine in the last years. Perhaps the Cuban system wasn't state-of-the-art here. Surely it's permitted to enquire whether he might still be alive if he'd had the best of western medical care.
Where do we keep all the oil we have stolen from Iran, Iraq , Venezuela et alia and why haven't they noticed its gone? Since chavez was a buffoon destroying his own economy and addicted to our oil money, why would we pick him of all the people in the world when so many need killing? What's our plan for getting their oil at less than market rates? Do your tin hats deflect ALL rational thought?
Reply | Report Abuse | Link to thisThe primary cancer in Venezuala was Chavez himself.
Reply | Report Abuse | Link to thisI'm a little surprised to see these accusations taken seriously. It's obviously a ploy to keep the anti-American fever running high long enough to elect Chavez's protoge to continue his ruinous policies.
I can think of a few ways that someone could be deliberately be infected with cancer that this article didn't mention. If someone had access to Chávez's drinking water or food they could poison it with aflatoxin, which I believe is one of the most carcinogenic substances known to man. But, I think that would still take multiple exposures to cause cancer. Also, someone could poison him with some sort of radioactive poison. Or, he could be poisoned with dioxin, similar to Viktor Yushchenko, which could cause cancer...but if poisoned with dioxin, or dioxin like compound, one would most likely develop cholracne, which I don't believe Chavez had. Or, if someone were able to obtain blood from Chavez then they could create a cancer specifically for him that would get past his immune system and then infect him with it.
Reply | Report Abuse | Link to thisBenzene causes cancer. Crude oil contains benzene. Venezuela's product is crude oil. Could Hugo Chávez Have gotten too close to Venezuela's product?
Reply | Report Abuse | Link to thisWikipedia says: 'One way of understanding the carcinogenic effects of benzene is by examining the products of biological oxidation. Pure benzene, for example, oxidizes in the body to produce an epoxide, benzene oxide, which is not excreted readily and can interact with DNA to produce harmful mutations."
and
"OSHA regulates levels of benzene in the workplace. The maximum allowable amount of benzene in workroom air during an 8-hour workday, 40-hour workweek is 1 ppm. Because benzene can cause cancer, NIOSH recommends that all workers wear special breathing equipment when they are likely to be exposed to benzene at levels exceeding the recommended (8-hour) exposure limit of 0.1 ppm."
"Benzene increases the risk of cancer and other illnesses. Benzene is a notorious cause of bone marrow failure. Substantial quantities of epidemiologic, clinical, and laboratory data link benzene to aplastic anemia, acute leukemia, and bone marrow abnormalities.[43][44] The specific hematologic malignancies that benzene is associated with include: acute myeloid leukemia (AML), aplastic anemia, myleodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML)."
"Benzene targets liver, kidney, lung, heart and the brain and can cause DNA strand breaks, chromosomal damage, etc."
Benzene is a very powerful carcinogen. "List of IARC [International Agency for Research on Cancer] Group 1 carcinogens
From Wikipedia, the free encyclopedia" includes Benzene in the list of the most carcinogenic chemicals.
It's pleasant to think, as the interviewee appears to, that to deliberately transmit cancer is so horrible that people wouldn't do it. But we haven't found anything so horrible that someone won't do it.
Reply | Report Abuse | Link to thisGovernments and criminal organizations (redundant?) are known enthusiasts for targeted assassination, and would effectively subsidize the development of a technology that would make it easy and reliable to undetectably murder a specific individual. Such murders may be ongoing, but without always attracting notice as deliberate acts. The murder of Georgi Markov by ricin injection was clumsy and in retrospect obvious, and perhaps ricin is insufficiently subtle for discreet political murder. But perhaps cancer is, or can be made to be.
My old undergraduate biology professor was outrage years ago when I suggested that eventually modern genetic engineering techniques would be used to create weapons. But that is like Alfred Nobel thinking that the invention of dynamite would put an end to war. Ha! Good luck with that.
Matisse, your comment "The theory that someone could be infected with cancer is not biologically impossible, but it is unlikely" is inaccurate and misleading to say the least.
Reply | Report Abuse | Link to thisAnyone familiar with recent history knows that the CIA developed such cancers way back in the 1960's as a way of eliminating opposition leaders. A statement such as yours, coming from a science writer for this esteemed magazine is almost unforgivable. I suggest that you learn more about your subject and its history, the next time you propose to write an article.
If I had to infect someone with cancer, I'd use plutonium, which is said that a minuscule ampunt of it is able to increase the risk of lung cancer by 60%, on the other hand, how much is a 60% of 1%?.
Reply | Report Abuse | Link to thisAnd then there is the reliability of such assasination attempt, if the cancer is found early, you have high chances of surviving it, and having time to investigate why did you got it, or simply to keep doing what you were doing that got you into the position for someone to want to give you cancer.
All in all, I think the Litvenko way or the rumanian that got killed by ricin pellet would be a better assasination way.
I don't believe any of the shit coming out of venezuela; the people in government there seem so weird!
Reply | Report Abuse | Link to thisIt is highly unlikely to infect someone with cancer unless maybe you have experimental and unrestricted access to the person.
Reply | Report Abuse | Link to thisNo reason to assassinate Chavez?
Reply | Report Abuse | Link to this5 WORDS: World's Largest Proven Oil Reserves
A random American living in 1980:
Reply | Report Abuse | Link to this"Stealth bomber? If it were [true], don't you think that it would have been obvious by now?!