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Re: Does CT lung cancer screening LOWER lung cancer risk?
Yes, John,
Smoking is the main cause of lung cancer and every day I help patients kick
that adrenalin fix.
As Otto points out also, the small numbers don't evidence much here.
Howard Long
----- Original Message -----
From: "John Jacobus" <crispy_bird@YAHOO.COM>
To: "Howard Long" <hflong@pacbell.net>; "John Jacobus"
<crispy_bird@YAHOO.COM>; "Keith Welch" <welch@jlab.org>;
<radsafe@list.vanderbilt.edu>
Sent: Sunday, June 20, 2004 7:16 PM
Subject: Re: Does CT lung cancer screening LOWER lung cancer risk?
> Howard,
> I would say that since the differences between actual
> and expected cancers is so small, neither a
> detrimental or beneficial effect can be demonstrated.
>
> I would say stop smoking would provide a greater
> benefit than any supposed CT radiation dosage. As a
> physician, wouldn't you agree?
>
> --- Howard Long <hflong@pacbell.net> wrote:
> > "4,687 non-leukemic cancer deaths occurred in 50,115
> > [exposed] survivors
> > where we estimated 4,306 would have occurred, had
> > they not been exposed [to
> > 1 to 10 cSv or rads]." (ref below). Indeed, that
> > would suggest a slight
> > INCREASE in cancer deaths from CT, (c 1 rad).
> >
> > However, the small difference (8%) might be
> > explained by many variables.
> >
> > Mostly I doubt the conclusion because it is
> > inconsistent with other data:
> > The Breast Cancer Incidence Among Atomic Bomb
> > Survivors (Land CE, McGrgor
> > DH, JNatl Cancer Inst 1979 Jan;62(1):17-21 table 2
> > shows "average tissue
> > dose, rads Observed 109 vs Expected 127.8 p,0.0001",
> > but broken down,
> > rads 1-9, Observed 34 breast cancers, Expected 42.3
> > breast cancers!
> >
> > Thus for that dosage, there is evidence that 1-9 rad
> > acute exposure may
> > LOWER breast cancer risk. I abandoned design for a
> > study using mammography
> > and CT
> > because the 1 rad acute from the CT would lower the
> > power to detect
> > significant differences, since it would have much
> > the same benefit as the
> > exposure (no good placebo). This is much the same
> > problem as drug companies
> > are having with placebo in anti depressants (Wall St
> > Journal, 6/18/04).
> >
> > I think CT may LOWER lung cancer risk.
> >
> > Howard Long
> >
> > ----- Original Message -----
> > From: "John Jacobus" <crispy_bird@YAHOO.COM>
> > To: "Keith Welch" <welch@jlab.org>;
> > <radsafe@list.vanderbilt.edu>
> > Sent: Friday, June 18, 2004 1:43 PM
> > Subject: Re: Article: Lung cancer screening raises
> > lung cancer risk
> >
> >
> > > The Radiation Effects Research Foundation show 63
> > > deaths (2% of 3391 cancer deaths) between 5 mSv
> > and
> > > 200 mSv
> > >
> > http://www.rerf.or.jp/eigo/radefx/late/cancrisk.htm
> > >
> > > Of course I have not read any of the reports which
> > > might have more current information. However, it
> > > appears to be a bit of data mining
> > (word-smithing?) to
> > > enhance the risk value.
> > >
> > > Keith, the HPS position paper I think you are
> > > referring to is at
> > > http://hps.org/documents/radiationrisk.pdf
> > >
> > > --- Keith Welch <welch@jlab.org> wrote:
> > > > Is this really right? Are the bomb survivor
> > > > statistics correct? How does the cancer risk in
> > the
> > > > atomic bomb cohort reconcile with the HPS
> > position
> > > > paper on "radiation risk in perspective" which
> > > > states that quantitative risk estimates should
> > not
> > > > be used below 10 rem? (coincidentally, it seems
> > > > that position paper is no longer on the HPS
> > website.
> > > > Is it under revision?)
> > > >
> > > > "For example, 10 low-dose CT lung screening
> > > > examinations would produce lung doses in the
> > range
> > > > of
> > > > 25 to 90 mGy," he wrote. "Among approximately
> > 30,000
> > > > individuals in the cancer incidence cohort of
> > atomic
> > > > bomb survivors who received doses between 5 and
> > 100
> > > > mSv (mean dose, 29 mSv), there was a
> > statistically
> > > > significant increase in cancer risk (77 excess
> > > > cancers, p = 0.05) compared to that in the
> > control
> > > > population."
> > > >
> > > >
> > > > Keith Welch
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