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From: bzs@bu-cs.UUCP (Barry Shein)
Newsgroups: net.sci,net.politics,net.med
Subject: Cancer -- was 'Plutonium'
Message-ID: <651@bu-cs.UUCP>
Date: Wed, 21-May-86 22:53:14 EDT
Article-I.D.: bu-cs.651
Posted: Wed May 21 22:53:14 1986
Date-Received: Sat, 24-May-86 03:46:42 EDT
Organization: Boston Univ Comp. Sci.
Lines: 72
Xref: linus net.sci:597 net.politics:15462 net.med:3837

I recently mentioned an article indicating a rise in Cancer mortality
that I had heard a review of in the news. This seems to have generated
a large amount of interest so I went and got the original article to
answer questions as I realized that the information I got from the
popular press was scanty. The article is:

	Bailar, John C., Smith, Elaine M., Progress Against Cancer?
	The New England Journal of Medicine, May 8, 1986, pp 1226-1232.

I recommend you read it but I'll try and summarize a few salient points
that I found interesting:

First, one must distinguish between cancer incidence rates and cancer
survival (or conversely, mortality) rates. They can fluctuate independantly
as this article indicates, the latter being some measure of treatment
effectiveness while the former simply being a measure of, as it is called,
incidence.

The thrust of the article was summed up as:

  "The main conclusion we draw is that some 35 years of intense effort
  focused largely on improving treatment must be judged a qualified
  failure." (p 1231)

Importantly, their interest was in mortality and thus treatment efficacy
rather than incidence. Thus it is not as relevant as I had thought to
the effects of spewing contaminants such as plutonium in the atmosphere.
On the other hand, it is interesting in that it does leave one with
the impression that at this juncture prevention is probably the only
tool we can rely on to lessen the likelihood of dying of cancer. That
is, once you have cancer there has been little progress over the
past 35 years (that's since 1950 in the text) in treatment, in fact,
in some cases your chances of survival seem to have worsened.
Even with lung, stomach and cervical cancers removed (the latter two
because the authors claim they have little correlation with treatment)
and age adjustment the mortality curve looks grim, basically flat
since 1950 ("130.1/10,000 in 1950, 128.9 in 1980 ... It is difficult
to claim success in the war against cancer on the basis of these figures",
p 1231.)

I for one believe that reducing the manifold introductions of
radioactive pollution from such sources as nuclear power plants,
nuclear waste disposal and nuclear bomb testing to be an important
step. It is not the only step, stopping smoking is clearly indicated
as being very important as lung cancer has remained the stubbornest
form of cancer to treat and both a very prevalent and preventable form
of cancer in that, unlike sources of environmental pollution, you have
control over it.  Perhaps it is for that very reason (that *I* don't
put radiation in my body nor can seem to stop others from doing it)
that I am on this particular soapbox. I think Chernobyl was strong
warning.

Even though lung cancer remains a major factor in the increase in
cancer mortality I for one worry if we are not being a little naive
in convincing ourselves that this is solely attributable to tobacco
smoking and is not related to the various contaminants our lungs
are constantly subjected to, there was no attempt by the authors
to analyze this as they were not particularly interested in causes
of incidence but rather treatments although they do mention smoking
in conjunction with lung cancer. Note for example the huge synergistic
effects between tobacco and asbestos exposure in lung cancer rates
even though asbestos alone is a proven, powerful lung carcinogen.

The bottom line seems to be, prevention.

Note: The authors are from the Harvard School of Public Health
and the University of Iowa Medical Center respectively.

	-Barry Shein, Boston University

	"...there is no reason to think that, on the whole,
	cancer is becoming any less common." (p 1229.)