RE: NCRP 136 / Immunology, DNA repair, cancer...

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

>I never realized that "cancer is determined by how the body is able to

defend itself." So, I guess the 25% of the population that get cancer have 

defective immune systems.

---

In order for the immune system to function on a cellular level there must be 

antigens that the immune system can react against. These antigens must in 

some way be "specific" to the tumor. In principle there are no such specific 

antigens (an exception is for testis tumors where certain antigens are 

immunologically invisible in the healthy individual).



A tumor that has lost important histocompatibility functions cannot be 

attacked by the immune system. Cellular immune defence works if the normal 

histocompatibility antigens are expressed. Any attack on tumors by the 

immunity system must be against tumor _associated_ antigens (as opposed to 

specific). A tumor that loses its antigens (HLA expressed)  becomes 

"invisible" in an immunological sense (associated with more aggressive 

stages of the tumors).



No antitumoral immununity effect has ever been shown. The only tumor that 

may provide an exception (but it is not clear at all) is chronic myeloid 

leukemia.



Any cellular mess on an immunological level (HLA antigens etc) can be 

expected to be more pronounced at later stages when there already is other 

types of chaos (on a DNA level) inside the cell. This is the overwhelming 

evidence. What seems to initiate and drive the startup of most tumors are 1/ 

mutations relating to DNA integrity (DNA repair, chromatin structure etc) 2/ 

mutations relating to the cell cycle.



Mutations in tumors that relate to receptor antigens, signals on a membrane 

level etc seem to statistically belong to a later stage. This is, according 

to my opinion, the overall impression.



Therefore, I don't think that the immunology has any important role in the 

protection against cancer.



For clarification: DNA repair is not a function relating to immunology.

Induced DNA repair or protection (could be phycico-chemical in nature) can 

be induced however but that is another issue.



My personal opinion,



Bjorn Cedervall    bcradsafers@hotmail.com

http://www.geocities.com/bjorn_cedervall/





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