|
New Blood test for cancer a breakthrough in detection
Cancer cells divide roughly 40 times before death occurs. Your death.
But even the best current cancer screening systems do not spot a cancer until it has already divided about 20 times. Physical symptoms of a tumour might not even appear until the division reaches 30 times.
Now two groups of scientists from Kansas and Nottingham University have developed a simple blood test which measures antibodies automatically produced by the immune system in response to the first sign of a cancer cell. Although the test was originally developed for lung cancer, its logic can be applied to any cancer. It could be the best screening test for cancer around in a couple of years.
As the first cancer cell develops, so it produces irregular proteins not normally present in the body. The immune system produces antibodies against these antigens, as they are called, immediately and so the test can pick up a cancer right from the outset. A pilot test, called the EarlyCDT-lung test, on lung cancer is already showing remarkable success with smokers.
The test will shortly be available in the UK but privately. Before the NHS adopts the test, the usual clinical trials will be needed.
Chris Comments: Apparently in the American Pilot test, merely having the test encouraged some smokers to wake up and stop smoking even though they tested clear.
Frankly, any test that does away with screening mammograms has got to be a good thing, especially if it proves 100 per cent accurate. (Mind you 60 per cent accuracy would be better than mammography, if the figures presented at the European Breast Cancer Symposium a couple of years ago are to be believed!)
And accuracy is a very big issue. We have already witnessed twenty years of the PSA test (which relies on measuring a protein antigen produced by the cancer), and even today some cancer centres say it is wonderful, while others deride it. Figures show at least one in eight PSA tests are inaccurate. So is this new test better, or are we getting carried away again?
Secondly, my concern is rushing off into treatment at the first sign of a protein. This is going to be a huge conundrum. We have recently had Danish Researchers studying mammograms where the unscreened group developed far less breast cancers across a six year period. The conclusion was not that mammograms caused cancer, but that the body was capable of healing itself in many cases if left alone. The researchers quoted other sources suggesting that many of us have cancer at least 6 times in our lives without ever knowing. The body deals with it. If we are to rush into drugs and cancer treatments at the first sign of an antibody, couldnt that be just as dangerous? I dont know. While discovering you have cancer cells present as early as possible will certainly mean more people will reach the 5-year survival point (irrespective of whether or not they have treatment), I would like to see if this means many, many more people will be simply diagnosed with cancer in this case a cancer that may never have ultimately taken hold of their body.
On balance this new test seems excellent news.
|