Detecting the otherwise undetectable

The perfect pill is the one which treats the feared but undetectable illness. It leads to sales in the billions as everyone seeks to take it. Day dream profits for a pharmaceutical company, Nobel prize for the scientists behind it, new energy for the global economy … enormous potential … but we are not there yet.

The idea of testing for the otherwise undetectable cancer is here. It is only one step more to get to the day dream. The test delivers genetic mutation information, this must have pharma companies salivating. The now-detected but otherwise undetectable cancer is not treatable by non-medical means unless it is allowed to develop to the point where it is identified and treatable … unless medical therapies are developed. Demand for those pills will be huge. Genetically targeted therapies cost thousands.

Roll on the pill revolution.

Is this blood test, which got so much press coverage over the weekend, really as valuable as reports suggest? Fortunately some level heads from UK academic research were more careful when interviewed. Lets also look at it from a patient viewpoint and ask if it will serve the objective of earlier diagnosis in the way which is being suggested.

Screening was implied. Screening who, is not explained. A screening method must balance its costs against the savings created by earlier detection. This means criteria to refine those screened to the most likely people to show a positive result. Screening also has downsides. It has false negatives (failing to spot someone with cancer) and false positives (indicating cancer when there is none present). It can lead to over treatment and unnecessary long term side effects. And of course it creates anxiety – which would include those who have been diagnosed too early to be effectively treated because no tumours are visible. This will create demand for a pill.

Used in primary care the test would have value if a practitioner suspects cancer. Today such patients are sent for imaging and other tests to gather actual evidence. A blood test may do that quicker and would have particular value where symptoms are vague. It could lead to a quicker and more accurate diagnosis in cases of real uncertainty. But treatment may not necessarily start more quickly … unless a pill is available.

Before introducing the test we would have to be certain that all rare forms of cancer can be covered, maybe not immediately but quite quickly after the test becomes standard practice. Expanding eight cancers to several hundred could prove challenging. Its no use saying to a patient your vague symptoms don’t show you have one of the eight cancers if they are shortly afterwards diagnosed with a rarer cancer. From a patient viewpoint cancer is cancer, the test failed.

So once again I am finding myself appealing for context when clever medical science is discussed. The idea of a blood test providing early recognition of cancer has important implications. If the technique comes through the next stages of research showing a high percentage of accurate diagnoses, covering more cancers, with few (if any) false negatives or positives in early stage otherwise unidentifiable cancer, then we will be able to think about changes in primary care practice. The proper analysis of practical and cost issues, including the cost implications of consequent medical therapy, can then be addressed.

I think this is all a long time away and I have to ask, is a pill the real objective of this research? Society needs better ideas than this one to detect cancer earlier. Don’t day dream too soon.