Politics of Cancer

Paul Henry Rosenberg rad at gte.net
Mon Jan 25 10:47:45 PST 1999


Kat McGowan wrote:


> >
> > >I find the figures given in the post partly copied below hard to believe. Does
> > >anyone have any comment?
> > >
> > >Carrol
> > >
> > >> In 1999, one in two American men and one in three American women will get
> > >> cancer. In the 1950s, one in four Americans were afflicted with this
> > >> deadly disease.
> >
>
> I had to de-lurk on this one. I got a similar email through another
> forward, and it got me riled. Number of problems with this, even if
> the projection is correct.
>
> #1: Cancer is mostly a disease of the old. People live longer & are
> much more likely to survive infectious disease, heart disease, stroke,
> than in 1950s--in short, cancer's much more likely to kill them simply
> because nothing else got to them first.

I've already answered this one twice. It is an effect, but the magnitude of increase overwhelms this effect.


> #2, diagnostic techniques have become much more sensitive (especially
> with the prostate specific antigen test), so the rate of *detection*
> has increased dramatically while death rates have stayed about the
> same or decreased somewhat for certain types of cancer (non-Hodgkin's
> lymphoma, eg.)I'm pretty sure that the official scientific consensus
> is that you can't really tell if more people have cancer now than in the
> 1950s.

There's a mish-mash of truth and fiction here. Yes, detection has improved, but early (pre-cancerous) detection can REDUCE incidence. (On a more detailed level, while death rates have decreased for some cancers, non-Hodgkin's lymphoma is not one of them [see below].)

If we were talking about "cancer" as a single disease, these objections might be harder to see through. But, in fact, what we see is different trends with different types of cancer, which helps us refute the notion that better detection is the dominant influence here.

*Living Downstream*, p. 41-2:

"Mortality and incidence do not always track each other. No cancers are increasing in mortality while dcreasing in incidence, but several cancers have increased in incidence even as their death rates have declined due to more effective treatments. According to SEER [Surveillance, Epidemiology and End Results, a National Cancer Institute-overssen tracking program] data, these include cancers of the ovary, testicle, colon and recturm, bladder, and thyroid.

"There are eight cancers whose incidence and mortality are both on the decline: those of the stomach, pancreas, larynx, mouth and pharynx, cervix, and uterus, as well as Hodgkin's disease and leukemia. Stomach cancer has been declining for decades, probably owning to improvements in food handling and the increased consumption of fresh foods made possible when refrigeration replaced more toxic methods of food preservation, such as smoking, salting and pickling. Pap smears have been credited with bringing down the incidence of cervical candcer because precanerous lesions can be detected and cut out before they are transformed into invasive tumors.

"However, these modest gains are swamped by the cancers that show both increasing incidence and increasing mortality: cancers of the brain, liver, breast, kidney, prostate, esophagus, skin (melanoma), bone marrow (multiple myelome), and lymph (non-Hodgkin's lymphoma) have all escalated over the past twenty years and show long-term increases that can be traced back at least forty years."


> Also--what does "get cancer" mean? Depends on how you define it.
> Doctors often can't agree on what is early cancer, pre-cancerous,
> or just weird cell growth. I can't remember if its half or most,
> but a lot of old men die with pre-cancerous or early-stage-cancer
> cells in the prostate--but they never knew about it, it didn't cause
> problems, and its not the cancer that kills them. Do they "have cancer"?

(1) While there may be problems with consistency of reporting, given the vast numbers we're dealing with, there's no reason to believe that any uncertainties involved produce a bias in one direction rather than another.

(2) As the passage above makes clear, early detection and treatment/removal of pre-cancerous cells (as with pap smears) is statitistically NOT counted as cancer and in fact can directly REDUCE incidence. After all, the cancer that's detected early but that doesn't result in successful preventative treatment would show up later on anyway.


> These numbers look like a classic case of factually correct, but terribly misleading.

I'm afraid this is more true of the objections you've raised than it is of the actual data.

Actually, that's too harsh. You make some good points, it's just that further investigation reveals that their impact is minimal with respect to the overall picture presented.

-- Paul Rosenberg Reason and Democracy rad at gte.net

"Let's put the information BACK into the information age!"



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