RE: [cdn-nucl-l] Fw: Chernobyl thyroid cancers

[JERRY CUTTLER <jerrycuttler@rogers.com>]

Zbigniew pointed out many years ago that thyroid cancer tumor nodules are quite common and are natural---nothing to do with radiation.  That's what was observed when screening of thyroids was carried out after the Chernobyl disaster.

 

I think the sentence "Radiation is a common cause of thyroid cancer" is very loose---not scientific at all.  It's just a scare.

Jaro <jaro-10kbq@sympatico.ca> wrote:

Dear Jerry & others, this might interest you....

Jaro
^^^^^^^^^^^^^^^^^^^^^


http://www.diagnosticimaging.com/showNews.jhtml?articleID=189400746
'Rise' in thyroid cancers comes from better detection methods
Diagnostic Imaging Online
June 14, 2006

More sophisticated detection methods account for a dramatic increase in
thyroid cancer over the last 30 years, rather than a true change in
occurrence of the disease, according to a study in the Journal of the
American Medical Association. Physician self-referral may also be a
contributing factor.

Radiation is a common cause of thyroid cancer, and some have questioned
whether the increase in thyroid cancer incidence was linked to greater
exposure to radiation in the environment.

But stable mortality rates despite the apparent rise in incidence led
researchers to conclude that the increase is actually due to better
detection, not greater occurrence of disease.

Dr. Louise Davies and Dr. H. Gilbert Welch of the VA Outcomes Group and
Dartmouth Medical Center investigated causes behind the increase of thyroid
cancer incidence from 3.6 per 100,000 in 1973 to 8.7 per 100,000 in 2002
(JAMA 2006;295:2164-2167).

The 2.4-fold increase is mostly due to the detection of subclinical
papillary cancers 2 cm or smaller. During the 30-year span, the incidence of
papillary cancers grew from 2.7 to 7.7 per 100 000, a 2.9-fold increase.

The researchers found no significant change in incidence of the less common
histological types: follicular, medullary, and anaplastic. In 2002, for
example, papillary cancers accounted for 88% of all thyroid cancers, while
9% were follicular, and 3% were either medullary or anaplastic.

"Given the known prevalence of small asymptomatic papillary thyroid cancers
at autopsy, we believe this suggests that increased diagnostic scrutiny has
caused an apparent increase in incidence of cancer rather than a real
increase," the authors said.

The use of ultrasound for thyroid disease became widespread in the 1980s,
while fine-needle aspiration flourished in the 1990s. Ultrasound can detect
nodules as small as 0.2 cm. FNA, which can be performed quickly during an
office visit, replaced lengthy nuclear medicine scans.

"The ability to detect small nodules and then aspirate their contents has
clearly facilitated the diagnosis of these smaller cancers," the authors
said.

In fact, overdiagnosis of the disease has itself become a concern. While
many people may die with papillary nodules, they do not die from them. Yet
75% of those with papillary cancers less than 1 cm undergo total
thyroidectomy. This procedure carries small but significant risks of
complications and requires lifetime maintenance and surveillance.

This concern is growing as thyroid ultrasound moves from the radiology
department to physicians' offices. When ultrasound is used as an
office-based adjunct to physical examination, the likelihood of
self-referral increases, along with the number of nodules -- and,
ultimately, cancers -- found and treated.

The authors suggest that follow-up for symptomatic thyroid nodules may be an
appropriate course and that papillary cancers smaller than 1 cm could be
classified as a normal finding.

They conclude that further research is needed to determine appropriate
management of small papillary cancers detected with ultrasound and
fine-needle aspiration. Data for the study came from Surveillance
Epidemiology and End Results (SEER) and the National Vital Statistics
System.

For more information from the Diagnostic Imaging archives:

Ultrasound helps reveal vascular patterns in thyroid cancer
http://www.dimag.com/showArticle.jhtml?articleID=170704231
=====================================



To: "Canadian Nuclear Discussion List"
, "ANS Member Exchange Listserv"

Subject: [cdn-nucl-l] Fw: Chernobyl thyroid cancers
From: "Jerry Cuttler"
Date: Mon, 12 Jun 2006 23:44:35 -0400

Not so rare at all ...

----- Original Message -----
From: "Zbigniew Jaworowski"
To: "Friends" ; ;

Sent: Monday, June 12, 2006 3:22 AM
Subject: Chernobyl thyroid cancers


> Friends,
> "The normally very rare thyroid (cancer) cases of young children" are not
> so rare at all. They are rare before screening, because they are "occult"
> and do not present any clinically adverse symptoms, usually untill the
> death in an old age.








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