Orac on the HIV/viral load paper

Posted by Tara C. Smith on October 3, 2006
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Orac has a post up on this new JAMA paper as well. He brings up some better examples than the one I gave:

Does anyone in this day and age still believe that smoking doesn’t cause lung cancer? The epidemiological evidence of the association is bulletproof. However, the majority of smokers don’t get lung cancer. In fact, there are complex statistical models that allow a pretty accurate calculation of risk in populations based on how long and how much a smoker has been smoking. For example, if you start smoking at age 18 and smoke two packs a day, by age 55, you have about a 5% chance of dying of lung cancer and by age 75 you have about a 20% chance of dying of lung cancer. That’s a far lower chance than an HIV-positive patient has of progressing to full-blown AIDS in 10 years (approximately 50%); yet no one seriously disputes that smoking is a very strong risk factor for lung cancer. At the population level, the association is very strong. However, if I see a 65-year-old patient who has been smoking since age 18, I can’t tell him whether he will definitely get lung cancer. I can only quote probabilities. Between two 65-year-olds who are heavy smokers, one may be perfectly fine and another may have stage IV lung cancer.

Let’s look at another example: Breast cancer. Let’s look at stage IV disease, which is, in essence, 100% fatal eventually. However, we do have pretty good estimates of median survival and what a patient’s chance of living 6, 12, 24, and 36 months are. However, when faced with a single breast cancer patient with stage IV disease, we are pretty poor at predicting how long that particular patient will survive. We can’t give a good answer to this poor hypothetical patient’s question, “How long have I got left?” We can only quote probabilities. One woman might deteriorate and die in 6 months, while all of us involved in the care of breast cancer patients have seen the occasional patient who has lived with metastatic disease for several years and done mostly well.

Examples like this abound in the medical literature. The fact that HIV “dissidents” again think this new paper describes some phenomenon unique to HIV again shows their ignorance of the totality of the biomedical literature.

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Comments

  1. #1 quitter
    October 3, 2006

    I’m not going to be happy until I have you calling them denialists too.

    Sorry to harp on this stuff, but I feel like this universal tactic for politicizing science and rejecting the truth for whatever reason deserves a descriptor and a universal response (immediate scorn). It seems like every single time anyone in science is challenged by someone with a political motive it’s using these same tactics. We should stop attacking the individual denialist causes and start attacking denialism directly. The war on science and rationality, from whatever source, is always using this same set of tactics, and we have to make it clear that these types of arguments are prima facie false.

    These are excellent examples examples of denialism using selectivity, and we should just reject it as such. Don’t argue with them over these silly claims when they’ve already failed from the start to make a reasoned argument (namely, how this explanation, like you say, fits with the totality of the literature). And I love the mention of the cigarettes and cancer link because the cigarette companies were the the original denialists using a heavily-monied campaign to sow confusion about the carcinogenicity of cigarettes. I think if we had recognized this tactic back then, and nipped it in the bud, it wouldn’t have taken 50 years to prove beyond all freaking reason (they particularly liked magnifying doubt/moving goalposts) that cigarettes cause cancer.

  2. #2 Charles Hoy
    October 4, 2006

    Does anyone in this day and age still believe that smoking doesn’t cause lung cancer?

    [giggle] Yeah, I do. As do many others. I won’t say that smoking is particularly healthy, but it definately doesn’t cause lung cancer.

    The epidemiological evidence of the association is bulletproof.

    Evidence is what you get when you leave out everything that contradicts your beliefs. Smoke=cancer evidence is as leaks about as much as HIV=Aids my dear.

  3. #3 quitter
    October 5, 2006

    My lord Tara, you actually managed to find someone who doesn’t think that cigarette smoking is carcinogenic!

    Behold the power of denialism.

    Yes it is amazing that people can still believe that in the face of study in animals and the wealth of epidemiologic information from humans’ experience with tobacco, namely that incredible increase in lung cancer rates concurrent with the rise of more mild cigarette tobacco allowing for a constant intake of drug. Or just the obvious data showing that lung cancer in a nonsmoker is incredibly rare, and is almost bizarre when it happens (usually requiring exposure to some other carcinogen but rarely people will get a small-cell carcinoma with no significant exposure risk), while being incredibly common in the smoker.

    The ability for someone to ignore the obvious in this way is pretty staggering which is why I think the issue of denialism itself is more important than individual topics that denialists attack.

  4. #4 Seth Manapio
    October 5, 2006

    “Yeah, I do. As do many others. I won’t say that smoking is particularly healthy, but it definately doesn’t cause lung cancer.”

    ——————-

    Black is white! Good is Evil! Truth is Fiction! Jefferson was the antichrist!

    I particularly like the ‘definitely’ part. Not “I’m not convinced” not “Studies are inconclusive” but right up to DEFINITELY NOT. No evidence, of course, just the declaritive.

    Classic.

  5. #5 Charles Hoy
    October 5, 2006

    No evidence, of course, just the declaritive.

    Evidence? You want evidence? I believe there is no definite evidence for anything but if you want, I have tons of what people normally call evidence. But always when I point to my ideas, the apologist dummies try to bite off my finger. So what do I care? People who don’t want to listen to anything new will stay stupid and there’s nothing I can do to change that.
    I’ve seen others advance the kind of ideas I agree with on this site but personally I have never shown any of my so-called evidence on this remarkable one-sided blog so let’s give it a try.

    What evidence do you want? Lung cancer is as common in smokers as it is in non-smokers. Where it all gets tricky is when you have to draw the frontier between smokers and non-smokers. A person who has been smoking from his 15th until his 30th birthday and who gets lung cancer at an age of 60, is he in the smoker’s or in the non-smoker’s stats? Already there are not so many people who never smoked a cigarette in their lives and, of course, today the last barriers to easy statistics are leveled. Secondary smoke! What an amazing trick of the apologist geniuses. Nobody in the whole wide world is save from secondary smoke and today ALL lung cancer can be traced back to cigarettes.

    But we should consider things differently. For example, everybody diagnosed with a severe disease like cancer or AIDS will end up having lung cancer. Look it up: Cancer metastasis in the lungs is the most common of secondary cancers. Which is very logical: People who are severely ill are very afraid and the cause of lung cancer is fear. Or, to be more precise, a biological conflict of “fear of death” is the cause if the lung alveoli are concerned.

  6. #6 Seth Manapio
    October 5, 2006

    “I believe there is no definite evidence for anything”

    “everybody diagnosed with a severe disease like cancer or AIDS”

    “the cause of lung cancer is fear”

    ————-

    Apparently, Hoy can be definite about something totally asinine in the complete absence of definitive evidence…. even things that aren’t actually facts in that conventional sense of the term. Again, note that the denier cannot keep a straight story, but changes his position paragraph by paragraph. Very interesting.

  7. #7 SLC
    October 5, 2006

    Re Charles Hoy.

    Of course smoking tobacco products doesn’t cause lung cancer and HIV doesn’t cause AIDS. Furthermore, germs don’t cause disease, the Sun goes around the Earth the Earth is flat, the Moon is made out of green cheese, Iraq had nuclear weapons, the Moon landing never took place, and the US Government brought down the World Trade Center, not 4 airliners. It’s all very simple, you’re just stupit if you don’t understand it.

  8. #8 quitter
    October 6, 2006

    For the reality-based readers, here’s a good overview of the facts

    Today, lung cancer is the leading cause of cancer death in the United States, and of cancer deaths worldwide. Lung cancer was rare in the nineteenth century, but its incidence increased dramatically throughout the twentieth century. It is now the leading cause of cancer mortality in both men and women, accounting for 31% of cancer deaths in men and 25% of cancer deaths in women [33]. Lung cancer is extraordinarily lethal, with more than 90% of affected patients dying of their disease [34]. Cigarette smoking is the primary cause of lung cancer, and the incidence of the disease in a given population largely reflects the prevalence of smoking that took place decades earlier. Populations with the highest incidence of lung cancer are those whose tobacco consumption had been highest during the previous three or four decades, and lower in countries where tobacco consumption has declined or increased only recently [35]
    …

    Multiple prospective cohort studies involving millions of people throughout the world have shown significantly higher lung cancer mortality rates among smokers than nonsmokers. In current male smokers, the relative risk for death from lung cancer compared with nonsmokers averages approximately 10-fold [33]. There is a strong dose-response relation between cumulative consumption of cigarettes and the risk for death from lung cancer. In the Cancer Prevention Study II, which included more than 1 million participants in the United States, followed for more than 6 years, men who smoked 20 cigarettes per day had 22 times the risk for dying from lung cancer when compared with lifetime nonsmokers. Those who consumed more than 41 cigarettes per day experienced a 45-fold increased risk of lung cancer. Other smoking-related factors contributing to a higher risk include earlier age of smoking initiation, deeper inhalation of tobacco smoke, higher tar and nicotine content of cigarettes, and the use of unfiltered cigarettes [31], [39], [40], [41].

    There is considerable evidence that the polycyclic aromatic hydrocarbons and nitrosamines enriched in cigarette smoke are strongly implicated in the causation of lung cancer. Polycyclic aromatic hydrocarbon DNA adducts and mutations in the tumor suppressor gene TP53 have been isolated in human lung cancer samples [2], [17], [18]. Nitrosamines have also been proved to induce lung tumors by DNA adducts [42], [43], [44]. Nitrosamine concentrations have increased in mainstream smoke from the 1950s to current times, resulting from changes in tobacco blends, and this may be responsible for the changing histology of lung cancer [45]. Adenocarcinoma has surpassed squamous cell carcinoma in lung cancer incidence. Publications have shown that nitrosamines and derivative metabolites primarily induce adenocarcinoma rather than squamous cell carcinoma in rat models [13].

    There are several important additional factors regarding lung cancer carcinogenesis that require notation. Risk reduction for the development of lung cancer has clearly been demonstrated by smoking cessation. As compared with continuous smokers, the excess risk of lung cancer sharply decreases in ex-smokers after approximately 5 years of cessation. Some risk probably persists throughout life; however, there are some reports demonstrating that the excess risk drops to baseline after 20 years [46]. Another important risk factor is age at which regular tobacco use began; smokers who started smoking before age 15 have a fourfold to fivefold higher risk of lung cancer than smokers who started at age 25 or later [46]. Also, the carcinogen content varies depending on the type of tobacco used. For example, black (air-cured) tobacco has a higher content of nitrosamines than blond (flue-cured) tobacco, and hand-rolled cigarettes have a higher tar content than filtered cigarettes.

    From: Levitz JS. Overview of smoking and all cancers. Med Clin North Am – 01-NOV-2004; 88(6): 1655-75

  9. #9 Unsympathetic reader
    October 8, 2006

    Charles Hoy writes: “Lung cancer is as common in smokers as it is in non-smokers.”

    Supporting references please.