A question regarding immune systems?

Hi There Folks

Cancer 101 - well I'm not the person to run this course. Also what I know about the immune system you could write on the back of a postage stamp in quite large letters. However, from what I have learned over the years is that cancer is an overall name for a variety of diseases, just as infection is a generic name for a wide variety of diseases. So some cancers are linked to an infectious agent such as human papilloma virus, hence a vaccine can be developed to prevent the HPV infection ending up as cancer. Other cancers are caused by agents that damage the DNA of normal cells and the resulting damaged cells develop into cancerous cells - so UV radiation and melanoma, smoking and certain types of lung cancer and head and neck cancer. Similarly there are a group of cancers that are occupation linked, so from what is known there are cancer causing agents in those particular workplaces that can result in cancer - for example the rubber industry and certain types of bladder cancer. Other cancer there are certain genes that are linked.

However, the problem is that we are dealing with population studies to find these things out and there is an awful lot of things we do not know. Most of us have at some stage or another been exposed to asbestos, but most of us will not get mesothelioma, only some will. So having a cancer linked gene increases the risk for the individual, it doesn't say they will get cancer. There are other factors involved.

I think that somewhere on the cancer councils website is a "what is cancer" section.

Hope that helps

Sailor

Never go into strange places on a falling tide without a pilot. Thomas Gibson Bowles

Hi Silly,

I don't think anyone knows the answer. I have never smoked, I've been vegetarian for over 25 years and prior to my tongue ( and subsequent neck cancer) I was slim and fit - gym 5 times a week, and very rarely sick. I am a teacher so my immune system is pretty good. My doctor told me that there were 5 main risk factors for tongue cancer - sharp teeth is the only category that applied to me. I feel that the immune system is very much involved, but just how, I don't know.

CJF

Hi,

The immune system is involved, but immune systems are complicated and the cell dynamics and biochemistry involved hurt my brain.

I'm not sure if terms like 'good' and 'strong' really apply to immune systems. Indigenous Australians for example would have had 'excellent' immune systems wholly adapted for the tough Australian continent and live outdoors, but then exposure to simple chicken pox took the lives of thousands of individuals.

Our immune systems are constantly adapting and learning. Its primary role is to recognize 'self' from 'non-self' and remove the non-self bits that pop up. These non-self bits can be bacteria, viruses, or cells that look and behave differently (ie. cancer cells).

Cancer actually hijacks a part of the human body's immune response and can recruit and then convert your immune cells to stop working for you and start working against you. That is why cancer is so dangerous - it uses complicated biochemistry to turn immune cells that were sent to destroy it into cells that then help it grow and spread.

This isn't a sign of a 'weak' immune system, it's a sign of a clever disease. And cancer can be considered very clever: 1 in 2 or 3 (depends on the report you are reading) people will get some type of cancer (ie. cells that grow into a tumour that the body has not removed).

There are so many types of cancer cells and cancer cell lines. Your body has been doing a good job removing cells with the potential to turn into cancer (cells that weren't copied correctly for example) since the moment you were conceived. And yes, it has been fighting colds and cuts that entire time too. Some places suggest that weird and potentially dangerous cells are produced over 10,000 times a day - you have never noticed this though because your immune system has been hard at work keeping things clean and tidy.

All it takes is one cancer cell to outsmart your immune system and avoid removal and however 'good' your immune system was until that point means nothing. Once your body fails to recognise that group of cells as 'non-self' your immune system has lost. It will still continue to fight all the things it has learnt to fight though such as colds and infections from cuts.

Ben

Thanks,you expressed this so clearly what I've read in some scholarly articles.If I understand it correctly different cancers can alter something in particular genes so that they can't do their job properly and they don't fight the cancer. Genetic research is so important because it may lead to treatments tailored to each type and stage of cancer. In the future,albeit a distant future, getting cancer may not be any worse than getting a bacterial infection.