Re: AW: Further thoughts on carcinogens

["Bjorn Cedervall" <bcradsafers@HOTMAIL.COM>]

>However, I wonder if such types of tests are really valid. If mutations 

>occurs in one test animal or cell line, does that mean that the substance 

>will cause cancer in humans?  Is there really an absolute

correlation?



The first papers about the mutation test in Salmonella typhimurium were 

published in the early 70:ies (1972-73?, one key paper by Bruce Ames was in 

PNAS in August 1973). I was working with the method (mixing the so called S9 

fraction with DNA and various nasty chemicals) in 1975 to test (mainly) 

alkylating agents for DNA damage - much was focused on reaction kinetics. I 

therefore followed the area closely for some years. As I remember the 

discussion around 1978 the performance of the test was interpreted as 

showing that something like 85 % of mutagens are carcinogens and 85 % of 

carcinogens are mutagens. I am sure that this view has been modified since 

then. What was recognized was that you need a battery of different kinds of 

experimental tests/indicators to show that something is carcinogenic (the 

nine Hill's criteria may be mentioned in this context).



Please comment if you think that this reflection needs to be improved,





Bjorn Cedervall    bcradsafers@hotmail.com

Assoc. Prof., Unit of Medical Radiation Physics,

Dept. Oncology and Pathology,

Karolinska Institutet, Box 260,

S-171 76 Stockholm, Sweden

Ph: Int + 468 336414

Fax: Int + 468 34 35 25

Mobile: Int + 4670 5395344





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