An interesting article from The Telegraph which to my mind poses an interesting dilemma in the ethics of mass screening when it involves radiation exposure as part of the screening process. Namely, is the risk of death from the screening process itself outweighed by the number of deaths prevented.

The opening from the article  :

People at a high risk of developing lung cancer could be screened for the disease in the future after the Government decided to pilot the idea.

The Department of Health-funded randomised controlled trial will initially involve 4,000 people in several local authority areas undergoing computerised tomography (CT) scans of their lungs, increasing to 32,000 in total next year.

CT scans uses low-dose radiation to build a high-resolution picture of soft tissue inside the body.

I already have issues with the last sentence mentioning “low-dose” before even getting to my main point.

CT scans or CAT scans involve large amounts of X-Rays. They are badged as nice and fluffy and safe because most people are wary of anything to do with radiation but in the case of CT scanning, the dose involved is actually quite high :

One study indicated that radiation by CT scans is often higher and more variable than cited and each of the 19,500 CT scans that are daily performed in the US is equivalent to 30 to 442 chest x-rays in radiation

In those terms, I suggest that CT scans should not really be seen as routine.

Imagine the reluctance to accept a “routine” CT scan if the following were prominently displayed in hospitals :

However, according to some estimates, the radiation exposure a patient receives from a full-body CT scan is often 500 times that of a conventional X-ray and about the same as that received by people living 2.4 kilometres away from the centres of the World War II atomic blasts in Japan.

Emotionally charged certainly but still showing CT scans for the high dose X-Ray machines dressed up as routine medical testing that they are.

Anyway, back to the point.

There have been several studies into the excess deaths from cancer due to CT scan X-Ray exposure and most point to a risk of getting cancer running at around 0.5% of people receiving a scan :

It has been estimated that CT radiation exposure will result in 29,000 new cancer cases just from the CT scans performed in 2007.  The most common cancers caused by CT are thought to be lung cancer, colon cancer and leukemia with younger people and women more at risk.

Claim source here

For the exact maths there that is 29000 cancer cases from 19500 scans er day over 365 days or 0.41% of total scans.

That would suggest that of the Department of Healths 32000 high risk guinea pigs, there will be around 131 new cancer cases due to the CT X-Ray exposure alone.

Around 6400 of those people will get cancer anyway at some stage (lifetime risk is around 20%) and possibly much more if the supposed “high risk” status is accurate but can we justify adding to that due to a preventative screening program?

Unfortunately due to the nature of the study involving people already at a high risk of lung cancer it would be difficult to attribute the cancers to the screening program itself :

According to details of the trial published in the journal Thorax, UK Lung Screen (UKLS) will choose patients aged 50 to 75 with a high risk of lung cancer – defined as a five per cent risk over five years – from NHS records.

One can only hope that the program saves more lives than it manages to kill although for our National Death Service, either outcome is seemingly a good result. It will also be interesting to see how well informed these trial patients are in terms of being told the extra risk of cancer that the scan itself involves.

One final point from the article, especially as it is one fact you don’t often see mentioned in the newspapers :

But Prot Field challenged what he called the “stigma” associated with lung cancer.

Many other cancers were the result of unhealthy lifestyles, he said.

He added: “Ten to 15 per cent of individuals who develop lung cancer have never smoked, which is more than the number of people who get ovarian cancer.

Not just smokers dying then as we are lead to believe by the bansturbators of this world although I am sure they would start waving 2nd, 3rd and nth hand smoking fake statistics around if asked.