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Re: Study Finds Increased Lung Cancer Risk Following TreatmentforHodgkin's Disease
Professor Field,
Yes, as I expect you teach (and I was taught at UCB 40 years ago),
"Only double-blind, placebo studies should imply cause" -and are definitive .
These, and these only, provide "identical controls".
Statistically significant associations (meaning only that variation without has
less than 5% probability of being from chance, considering the variation within)
are merely "suggestive" - and of interest only as they fit other studies, have
cofounder consistency, fit related laboratory explanation of mechanisms, etc
Professr Cohen won accolades for great effort to disprove his finding that LNT
could not fit. Your case control study, likewise?
Howard Long.
"Field, R. William" wrote:
> Howard,
>
> Regarding your repeated assertions that the use of non identical controls
> invalidates findings from a case-control study, could you provide
> documentation (references) to support your assertion? By the way, what is
> an identical control?
>
> Bill Field
>
> At 06:54 PM 02/06/2002 -0800, hflong@postoffice.pacbell.net wrote:
> >1. Non-identical "controls", prohibit inference that "radiation caused
> >more cancer" here,
> >2. --as in the Iowa Study.
> >3. Also, the treatment dose was over the approx 50 rem "threshold" where
> >benefit turns to harm (cited by Luckey and ignored by LNT)
> >
> >Howard Long
> >
> >"Jacobus, John (OD/ORS)" wrote:
> >
> > > Howard,
> > > What are you talking about? What does this have to do with the Iowa study?
> > > What threshold are you talking about? The minimum treatment?
> > >
> > > -- John
> > > John Jacobus, MS
> > > Certified Health Physicist
> > > 3050 Traymore Lane
> > > Bowie, MD 20715-2024
> > >
> > > E-mail: jenday1@email.msn.com (H)
> > >
> > > -----Original Message-----
> > > From: hflong@postoffice.pacbell.net
> > > [mailto:hflong@postoffice.pacbell.net]
> > > Sent: Wednesday, February 06, 2002 3:57 PM
> > > To: Dukelow, James S Jr
> > > Cc: Jacobus, John (OD/ORS); RadSafe
> > > Subject: Re: Study Finds Increased Lung Cancer Risk Following Treatment
> > > fo r Hodgkin's Disease
> > >
> > > Cancer threshold?
> > > As in the Iowa study, apparently "controls" here were different from cases
> > > in ways that could explain association without the implied causality. In
> > > Iowa, it was smoking (only 32% of controls). Here, sicker Hodgkin's Disease
> > > patients would seem more likely to receive radiation, chemotherapy, and
> > > especially both - and these are the very patients more likely to get other
> > > cancers, (with or without the treatment, implied here to cause the other
> > > cancer).
> > > Common Cause.
> > >
> > > Above threshold dose also says nothing about rate of cancer with below
> > > threshold dose (an argument you've seen before here).
> > >
> > > Only double-blind, placebo studies should imply "cause".
> > > Others, like this one, are more accurately, "suggestive".
> > >
> > > Howard Long
> > >
> > > "Dukelow, James S Jr" wrote:
> > >
> > > > John Jacobus passed along to us:
> > > > -----Original Message-----
> > > > From: Jacobus, John (OD/ORS) [mailto:jacobusj@ors.od.nih.gov]
> > > > Sent: Wednesday, February 06, 2002 9:21 AM
> > > > To: RadSafe
> > > > Subject: Study Finds Increased Lung Cancer Risk Following Treatment for
> > > > Ho dgkin's Disease
> > > >
> > > > I received this from another mailing list and thought I would pass it
> > > along.
> > > >
> > > > -- John
> > > >
> > > > <snip>
> > > >
> > > > National Institutes of Health:
> > > > NCI Press Office (301) 496-6641
> > > > EMBARGOED FOR RELEASE
> > > > 4pm EST
> > > > Tuesday, February 5, 2002
> > > >
> > > > Study Finds Increased Lung Cancer Risk Following
> > > > Treatment for Hodgkin's Disease
> > > >
> > > > People with Hodgkin's disease (HD) who receive
> > > > chemotherapy, radiotherapy, or a combination of the two
> > > > treatments, are at higher risk of developing lung cancer,
> > > > according to a report in the Feb. 6, 2002, issue of the
> > > > Journal of the National Cancer Institute.* The study also
> > > > finds a higher risk for lung cancer among smokers treated
> > > > with both radiotherapy and chemotherapy.
> > > >
> > > > "It was the combined effect of smoking and treatment that
> > > > accounted for the bulk of lung cancers in this study,
> > > > underscoring the importance of smoking cessation in the
> > > > management of patients with Hodgkin's disease," the
> > > > authors conclude. "It is clear that the tremendous
> > > > improvement in the treatment of HD far outweighs any
> > > > therapy-related risks of lung cancers, especially when
> > > > compared with the enormous burden imposed by tobacco,"
> > > > said Lois Travis, M.D., Sc.D., of the National Cancer
> > > > Institute's Division of Cancer Epidemiology and Genetics
> > > > in Bethesda, Md., and first author of the study.
> > > >
> > > > <snip>
> > > >
> > > > For this study, the researchers looked at many different
> > > > factors, but focused on three main measures: the type and
> > > > cumulative amount of chemotherapy drugs, the radiation
> > > > dose, and tobacco use. All three exposures contributed
> > > > significantly to elevated lung cancer risks. Tobacco use,
> > > > chemotherapy, and radiotherapy doses of five Gray (Gy) or
> > > > more were reported in 96 percent, 63 percent, and 53
> > > > percent of case subjects (those who developed lung
> > > > cancer), respectively, and in 70 percent, 52 percent, and
> > > > 41 percent of patients who did not develop lung cancer.
> > > >
> > > > Subjects who received either radiotherapy alone or
> > > > chemotherapy with drugs called alkylating agents
> > > > experienced a significantly increased risk of lung cancer.
> > > > And when researchers looked at the group of patients who
> > > > received both alkylating agents and radiotherapy, the
> > > > numbers showed risks that were additive.
> > > >
> > > > <snip>
> > > >
> > > > =================
> > > >
> > > > Jim Dukelow comments:
> > > >
> > > > Something is strange here -- or, perhaps, I am missing something.
> > > >
> > > > It is reported that of the 444 control subjects (all of whom had been
> > > > treated for HD and had not developed lung cancer), 52% are reported to
> > > have
> > > > had chemotherapy and 41% reported to have had radiotherapy. And the
> > > missing
> > > > 7% -- "Take two aspirin and call me in the morning"?
> > > >
> > > > Also, the press release talks about patients who received radiotherapy
> > > ALONE
> > > > or chemotherapy with drugs called alkylating agents [with an implied
> > ALONE
> > > > there also] having so much of a risk increase. This is disingenuous,
> > > since
> > > > 96% of the "cases" -- those with lung cancer -- were smokers.
> > > >
> > > > Best regards.
> > > >
> > > > Jim Dukelow
> > > > Pacific Northwest National Laboratory
> > > > Richland, WA
> > > > jim.dukelow@pnl.gov
> > > >
> > > > These comments are mine and have not been reviewed and/or approved by my
> > > > management or by the U.S. Department of Energy.
> > > > ************************************************************************
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